Category Archives: Healthy Aging

Low LDL cholesterol associated with worse cognitive performance

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Summary: cholesterol plays critical roles in cell membranes and steroid hormone production. This study associates low LDL cholesterol with worse cognitive performance. As expected, the effect is amplified by inflammation. Care should be taken to apply a balanced approach to cholesterol lowering therapies.

A truly fascinating study was just published in the journal Neurobiology of Aging investigating lipoproteins and loss of cognitive function. The authors state:

“The aim of this study was to examine the associations between high-density lipoprotein (HDL) and low-density lipoprotein (LDL) cholesterol, triglycerides, and cognition and focus on the modifying effect of inflammation.”

They collected biological and cognitive data on 1003 persons ≥ 65 years of age over 6 years of follow-up, measuring cognition with the Mini-Mental State Examination (general cognition), Auditory Verbal Learning Test (memory), and Coding Task (information processing speed). High HDL was associiated with better memory performance, but their data seem to suggest the importance of sufficient LDL cholesterol in brain neuronal membranes:

“We found an independent association between high HDL cholesterol and better memory performance. In addition, low LDL cholesterol was predictive of worse general cognitive performance and faster decline on information processing speed.”

Not at all surprisingly they found that inflammation compounds the adverse effects of low LDL:

“Furthermore, a significant modifying effect of inflammation (C-reactive protein, α-antichymotrypsin) was found. A negative additive effect of low LDL cholesterol and high inflammation was found on general cognition and memory performance.”

And since high triglycerides are commonly provoked by the high insulin levels due to insulin resistance which also have deleterious effects on the brain…

“Also, high triglycerides were associated with lower memory performance in those with high inflammation.”

The authors conclude by suggesting that HDL, LDL and inflammatory indicators can be used as predictors of poor cognitive function:

“Thus, a combination of these factors may be used as markers of prolonged lower cognitive functioning.”

This compels us to use caution and see the ‘big picture’ when designing strategies to manage lipids—care should be taken to not suppress LDL cholesterol to too low a level.

The important role of autoimmunity in cardiovascular disease

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Summary: Inflammation of the blood vessels is the fundamental factor in cardiovascular diseases including heart attack and stroke. Vascular inflammation due to autoimmunity, a widespread phenomenon, is not encompassed by the ‘traditional’ metabolic risk factors. In the clinic the autoimmune components of vascular disease must be investigated and treated.

The authors of a paper published in the clinical journal Mædica observe:

“Inflammation plays a crucial role in atherogenesis either by local cellular mechanisms or humoral consequences…inflammation and endothelial dysfunction are triggered by cardiovascular risk factors: hypercholesterolemia, hypertension, smoking or diabetes. In other cases inflammation precedes atherosclerotic changes that occur in autoimmune diseases, as systemic lupus erythematosus and rheumatoid arthritis. In these diseases atherogenesis is mostly independent from conventional risk factors. Irrespective of its cause systemic inflammation is correlated with cardiovascular events.”

They also note:

“The pathogenic mechanisms of autoimmune disorders include an important localized or systemic inflammatory response. This may trigger as an “innocent bystander” reaction a peculiar type of endothelial injury that predisposes to atherogenesis. Many of these diseases are associated with early, accelerated atherosclerosis. This can also be due to concomitant presence of conventional risk factors, but is determined mainly by specific autoimmune and pro-inflammatory mechanisms or by specific medication (i.e. long term systemic corticosteroid use). In these cases atherosclerosis occurs in population subgroups traditionally protected from the atherosclerotic process, as young women that develop systemic lupus erythematosus. Atherothrombosis became the main cause of mortality in autoimmune disorders…Endothelial dysfunction found in early stages of athero genesis in autoimmune diseases is independent from traditional risk factors, depends only on the severity of systemic inflammation.”

As stated by the authors of a paper published in The Netherlands Journal of Medicine, autoimmune conditions such as rheumatoid arthritis and SLE have long been known to increase cardiovascular risk:

“Immune-mediated inflammatory diseases (IMIDs), including rheumatoid arthritis and spondyloarthritis, are associated with increased cardiovascular morbidity and mortality, independent of the established cardiovascular risk factors. The chronic inflammatory state, a hallmark of IMIDs, is considered to be a driving force for accelerated atherogenesis.”

They discuss autoimmunity and cardiovascular disease using as models RA, psoriatic arthritis and ankylosing spondyloarthritis, SLE and role of innate and adaptive immunity, concluding:

“Over the past two decades it has become increasingly clear that chronic inflammation is an independent risk factor for cardiovascular events, with an impact over and above established risk factors. Since IMIDs are protracted disorders, the focus on adequate cardiovascular prevention in these patients is long overdue. Pathophysiologically, chronic inflammation provides a direct link between IMIDs and accelerated atherogenesis.”

A fascinating review article, rich with references to other valuable citations, was published recently in the International Journal of Inflammation that expands on the role of oxidative stress in eliciting an autoimmune response that produces cardiovascular inflammation. The authors state:

“Recently, it has become clear that atherosclerosis is a chronic inflammatory disease in which inflammation and immune responses play a key role. Accelerated atherosclerosis has been reported in patients with autoimmune diseases, suggesting an involvement of autoimmune mechanisms in atherogenesis. Different self-antigens or modified self-molecules have been identified as target of humoral and cellular immune responses in patients with atherosclerotic disease. Oxidative stress, increasingly reported in these patients, is the major event causing structural modification of proteins with consequent appearance of neoepitopes. Self-molecules modified by oxidative events can become targets of autoimmune reactions, thus sustaining the inflammatory mechanisms involved in endothelial dysfunction and plaque development.”

The authors acknowledge the role of infectious agents as instigators of autoimmune activity, but emphasize the role of modified self-antigens:

“Although infectious agents have been associated with the activation of immune mechanisms, evidence exist that the main antigenic targets in atherosclerosis are modified endogenous structures [12]. Atherosclerotic plaques express autoantigens that are targeted by both IgM and IgG. It is likely that these autoimmune responses initially have a beneficial effect facilitating the removal of potentially harmful antigens [13, 14]. However, studies performed on hypercholesterolaemic mice deficient in different components of innate and adaptive immunity uniformly indicate that the net effect of immune activation is proatherogenic and that atherosclerosis, at least to some extent, should be regarded as an autoimmune disease.”

They go on to discuss the roles of oxidized LDL, heat shock proteins, Beta2-glycoprotein I (β2-GPI), and oxidized hemoglobin as oxidized agents that act as autoantigens eliciting an autoimmune response implicated in atherogenesis and cardiovascular disease, then conclude by stating:

“Excessive oxidative stress and low-grade chronic inflammation are major pathophysiological factors contributing to the development of cardiovascular diseases…In addition to pro-inflammatory properties, self molecules modified by oxidative events can become targets of autoimmune reactions, thus sustaining the inflammatory mechanisms involved in endothelial dysfunction and plaque development…Modulation of the immune system could represent a useful approach to prevent and/or treat these diseases.”

An excellent paper published in the journal Nature Reviews Rheumatology (formerly Nature Clinical Practice Rheumatology) discusses the mechanisms of atherosclerosis in autoimmune diseases. The authors note:

“Many components of the immune system are involved in the pathologic processes underlying the development of atherosclerosis: macrophages that develop into foam cells; T cells; autoantibodies; autoantigens that are components of vessel walls and cholesterol particles; and cytokines that are secreted by cells within atherosclerotic plaques, including interleukin (IL)-1, IL-2, IL-6, IL-8, IL-12, IL-10, tumor-necrosis factor, interferon-gamma and platelet-derived growth factor.”

They note evidence for the role of cellular immunity…

“Several autoimmune diseases are characterized as being TYPE 1 T HELPER (TH1) CELL-mediated or TYPE 2 T HELPER (TH2) CELL-mediated conditions. A study in which ApoE-/- mice were treated with pentoxifylline (an inhibitor of the TH1 differentiation pathway) for 12 weeks suggested that atherosclerosis is a TH1-mediated process.”

And the participation of humoral immunity is characterized by antibodies to oxidized LDL cholesterol and to heat-shock proteins (HSPs):

“Oxidized LDL (oxLDL) is the type of LDL cholesterol most likely to be taken up by macrophages that develop into foam cells. Increased levels of anti-oxLDL antibodies have been detected in patients with early-onset peripheral vascular disease, severe carotid atherosclerosis, and angiographically verified coronary artery disease (CAD). In addition, raised levels of oxLDL antibodies were found to be predictive of progression of carotid atherosclerosis, MI, and death…it was found that individuals with atherosclerosis had significantly higher levels of anti-HSP65 antibodies than controls.”

It has long been known that antiphospholipid antibodies (aPL) and anticardiolipin antibodies (aCL) can be associated with cardiovascular disease, and the authors discuss their relation to arterial intima–media thickness (IMT, pathological thickening of the blood vessel wall). They conclude:

“The complex involvement of the immune system in the pathogenesis of atherosclerosis is most evident in patients with autoimmune diseases, but is also important in the general population. Immunomodulation of atherosclerosis carries great potential for future human therapies…

  • Autoimmune rheumatic diseases are characterized by enhanced atherosclerosis, which leads to cardiovascular disease
  • Some forms of atherosclerosis can be detected at the preclinical stage
  • Both cellular and humoral components of the immune system are involved in the pathogenesis of atherosclerosis
  • Classical and nonclassical risk factors for atherosclerosis are associated with accelerated atherosclerosis in autoimmune rheumatic diseases
  • Atherosclerosis can be immunomodulated in experimental models in various ways, which include induction of immune tolerance”

The authors of a paper published in the journal Stroke observe that inflammation plays the critical role in arterial plaque destabilization:

“Inflammation is not only instrumental in the development of human atheromatous plaques, but, importantly, plays a crucial role in the destabilization of internal carotid artery plaques, thus converting chronic atherosclerosis into an acute thrombo-embolic disorder.”

Expanding on this…

“…a complex endothelial dysfunction induced by elevated and modified low-density lipoproteins (LDL), free radicals, infectious microorganisms, shear stress, hypertension, toxins after smoking or combinations of these and other factors leads to a compensatory inflammatory response. Endothelial dysfunction is characterized by decreased nitric oxide synthesis, local oxidation of circulating lipoproteins and their entry into the vessel wall. Intracellular reactive oxygen species similarly induced by the multiple atherosclerosis risk factors lead to enhanced oxidative stress in vascular cells and further activate intracellular signaling molecules involved in gene expression. Upregulation of cell adhesion molecules facilitates adherence of leukocytes to the dysfunctional endothelium and their subsequent transmigration into the vessel wall. As outlined in this review, the evolving inflammatory reaction is instrumental in the initiation of atherosclerotic plaques and their destabilization.”

The authors summarize the stream of events leading to plaque rupture:

“Inflammation plays an important role in the progression of atherosclerosis and ICA plaque destabilization converting a chronic process into an acute disorder with ensuing thrombo-embolism. During atherosclerosis, T cells and macrophages infiltrate the vessel wall triggered by endothelial dysfunction, and locally interact in a synergistic manner. Autoreactive T cells recognize oxLDL, HSP and shared microbial antigens by molecular mimicry and locally release proinflammatory cytokines. Macrophages on stimulation by T-cell-derived cytokines and transformation into foam cells after uptake of oxLDL secrete MMP predisposing the plaques to subsequent rupture. Plaque-associated macrophages, moreover, are an important cellular source of TF. On plaque rupture TF-rich plaque material gets in contact with the circulation and activates the extrinsic coagulation pathway…Vaccination against modified LDL and HSP can slow development of atherosclerotic plaques. Current therapeutics effective in preventing atherosclerosis and stroke such as statins, ASS [aspirin] and renin-angiotensin system inhibitors may exert part of their effects by modulating inflammatory responses in the vessel wall.”

The authors of a review article published in Clinical and Developmental Immunology consider epigenetic mechanisms involved in autoimmune cardiovascular risk. They state:

“Autoimmune diseases (AIDs) have been associated with accelerated atherosclerosis (AT) leading to increased cardio- and cerebrovascular disease risk…many new genes and signalling pathways involved in autoimmunity…have been further detected. Epigenetics, the control of gene packaging and expression independent of alterations in the DNA sequence, is providing new directions linking genetics and environmental factors. Epigenetic regulatory mechanisms comprise DNA methylation, histone modifications, and microRNA activity, all of which act upon gene and protein expression levels. Recent findings have contributed to our understanding of how epigenetic modifications could influence AID development.

In other words, environmental factors that modulate gene expression play a role in ‘turning on’ autoimmunity that promotes heart attacks and strokes. As the authors note:

“It is widely known that AIDs are the result of interaction between predisposing genetic factors, deregulation of the immune system, and environmental triggering factors.”

Of great importance is that these factors can be modified:

“Moreover, epigenetic changes may be reversed. A remarkable example of disease in which epigenetic abnormalities and patterns of inheritance are extremely complex is SLE. The high incidence of twin pairs in which SLE develops in only one of the siblings supports the notion that environmental factors and their involvement in epigenetic modifications could affect the onset of disease.”

And there seem to be differences of autoimmune expression depending on the disease and the individual:

“Significant evidence has shown that there is heterogeneity in the characteristics of vasculopathies underlying different autoimmune diseases such as APS, SLE, RA, and pSS. It has been also shown a relevant heterogeneity with respect to inflammatory risk factors. The data presented in this revision further indicated that epigenetic mechanisms also seem to influence inflammation and cardiovascular disease in those autoimmune conditions.”

The authors of a paper published in Zeitschrift für Rheumatologie (Journal of Rheumatology) note that EULAR (the European League Against Rheumatism) recommends aggressive cardiovascular risk factor management for rheumatoid arthritis, which would be reasonable extrapolate to other autoimmune diseases:

“Beyond the traditional CV risk factors, chronic systemic inflammation has been shown to be a crucial factor in atherosclerosis development and progression from endothelial dysfunction to plaque rupture and thrombosis. Numerous studies have shown that atherosclerosis is not a passive process characterized by accumulation of lipids in the vessel walls, but rather represents active inflammation of the vasculature…According to the recently published EULAR recommendations for CV risk screening and management in patients with inflammatory arthritis, annual CV risk assessment is recommended for all patients with RA. Any CV risk factors identified should be optimally managed. In addition to appropriate CV risk management, aggressive suppression of the inflammatory process is recommended to further lower CV risk.”

Stroke in young women, particularly in the absence of ‘traditional’ risk factors such as elevated cholesterol, hypertension, metabolic syndrome and obesity, etc. is a great concern. In a paper published recently in the Canadian Journal of Neurological Sciences the authors state:

“In women ages 15-45 years, an additional set of risk factors are important in the pathogenesis of ischemic stroke. Some of these pertain strictly to women, and relate to exogenous hormones and pregnancy. Various other conditions are more common in women, which include migraine with aura, selected vascular disorders and autoimmune conditions. These differences do have implications for management in both the primary and secondary prevention of stroke in this age group.”

Of interest to clinicians is another paper in the same journal drawing attention to the role of the cytokine transforming growth factor-β (TGF-β) in vascular inflammation. The authors investigated polymorphisms of the TGF-β gene in ischemic stroke:

“Inflammation plays a pivotal role in the pathogenesis of atherosclerosis and of cerebrovascular complications. Transforming growth factor-β (TGF-β) is a pleiotropic cytokine with a central role in inflammation. To investigate whether polymorphisms of the TGF-β1 gene can modify the risk of ischemic stroke (IS) in Chinese population, we conduct this hospital-based, case-control study.”

They determined the transforming growth factor-β1 genotype in 450 Chinese patients (306 male and 144 female) with ischemic stroke compared to 450 control subjects (326 male and 124 female).

“Subjects carrying 869TT were susceptible to IS (odds ratio [OR] =1.58). Further analysis of IS data partitioned by gender revealed the female-specific association with 869T/C (OR=2.64).”

While the 869TT genotype of the TGF-β1 gene increased the risk of stroke for both sexes, the increase in risk for stroke was 264% for females.

The authors of an interesting paper published recently in the Endocrine Journal investigate the association of chronic inflammation in autoimmune thyroiditis with endothelial (vascular) dysfunction:

“Our study aims to investigate the presence of the well known preceding clinical situations of atherosclerosis like endothelial dysfunction and inflammation in subclinical hypothyroidism.”

They evaluated 37 patients with subclinical hypothyroidism (29 women, 8 men) in comparison to 23 healthy volunteers (19 women, 4 men) for endothelial dysfunction as measured by brachial artery responses to endothelium-dependent (flow mediated dilation, FMD) and endothelium-independent stimuli (sublingual nitroglycerin (NTG)). They also measured serum TNF-alpha, interleukin-6, and hs-CRP, and estimated insulin resistance by HOMA score. The data make paint an interesting picture:

“There were no significant differences in age, body mass index, waist circumference, HOMA scores. There was a statistically significant difference in endothelium-dependent (FMD) and endothelium-independent vascular responses (NTG) between the patients with subclinical hypothyroidism and the normal healthy controls…The TSH and LDL, IL-6, TNF-alpha and hs-CRP levels in the patient group were significantly higher than those in control group. A positive correlation was found only between endothelium-dependent vasodilation and TNF-alpha, hs-CRP and IL-6, TSH, total cholesterol, LDL and triglycerides. Neither of the groups were insulin resistant and there was not any difference either in fasting insulin or in glucose levels. We found endothelial dysfunction in subclinical hypothyroidism group.”

The vascular inflammation associated with autoimmune thyroiditis stands out in high relief against a background of normal traditional risk factors like BMI, waist circumference and insulin resistance. The authors conclude:

“Our findings suggest that there is endothelial dysfunction and low grade chronic inflammation in SH due to autoimmune thyroiditis. There are several contributing factors which can cause endothelial dysfunction in SH such as changes in lipid profile, hyperhomocysteinemia. According to our results low grade chronic inflammation may be one of these factors.”

Finally, in the journal Circulation Research the authors of a commentary  on a study just published in the Journal of Clinical Investigation ask the question “Is Atherosclerosis an Allergic Disease?“:

“A new report in the Journal of Clinical Investigation adds to the ever-increasing evidence that immunological mechanisms play an important role in atherogenesis. These new observations suggest involvement of IgE and its FcϵR1α receptor in the promotion of atherosclerosis, and specifically in plaque instability and clinical events.”

They further note, importantly…

“In addition, aside from conditions in which there are generalized increases in IgE levels, such as parasitic infections and hyper-IgE syndromes, elevated IgE levels usually reflect allergic-type immune responses.”

This is one mechanism by which food and other allergies contribute to the inflammation of cardiovascular disease. The authors conclude:

“The report by Wang et al and other reports describing the potential importance of mast cells to CVD have provided a compelling case to study the role of IgE in inflammatory conditions such as atherosclerosis. It adds to the growing evidence of the importance of immune function in atherogenesis and in particular of the role that immunoglobulins play, both through antigen-specific interactions and antigen-independent regulatory roles.”

Bottom line: In clinical management of cardiovascular disease the autoimmune components should be investigated and addressed with a rational treatment strategy.

Diabetes is a significant risk factor for all-cause dementia and Alzheimer’s disease

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There has been a burst of papers drawing further attention to the damage that glucose and insulin dysregulation does to the brain. A study just published in the journal Neurology investigates specifically…

“…the association between glucose tolerance status defined by a 75-g oral glucose tolerance test (OGTT) and the development of dementia.”

The authors subjected 1,017 community-dwelling dementia-free subjects 60 years and older to an oral glucose tolerance test, then followed them for 15 years. The outcome measure was clinically diagnosed dementia. What did their data show?

The age- and sex-adjusted incidence of all-cause dementia, Alzheimer disease (AD), and vascular dementia (VaD) were significantly higher in subjects with diabetes than in those with normal glucose tolerance. These associations remained robust even after adjustment for confounding factors for all-cause dementia and AD, but not for VaD (all-cause dementia: adjusted hazard ratio [HR] = 1.74; AD: adjusted HR = 2.05; VaD: adjusted HR = 1.82). Moreover, the risks of developing all-cause dementia, AD, and VaD significantly increased with elevated 2-hour postload glucose (PG) levels even after adjustment for covariates, but no such associations were observed for fasting plasma glucose (FPG) levels: compared with those with 2-hour PG levels of <6.7 mmol/L [120.6 mg/dl], the multivariable-adjusted HRs of all-cause dementia and AD significantly increased in subjects with 2-hour PG levels of 7.8 to 11.0 mmol/L [140.4 to 198 mg/dl] or over, and the risk of VaD was significantly higher in subjects with levels of ≥11.1 mmol/L [199.8 mg/dl].”

This is striking. The risk of all-cause dementia doubled for those with diabetes, and there was a significant increase in the risk of all-cause dementia and Alzheimer’s disease with a 2 hour post-glucose load level of 140.4 mg/dl or more. Moreover, fasting glucose levels did not reveal the danger that was disclosed only by the functional OGTT. I always risk desensitizing my patients to the damage done to the brain by glucose and insulin dysregulation; better to let the authors’ conclusion do the talking:

“Our findings suggest that diabetes is a significant risk factor for all-cause dementia, AD, and probably VaD. Moreover, 2-hour PG levels, but not FPG levels, are closely associated with increased risk of all-cause dementia, AD, and VaD.”

Meanwhile, a time study just published in the journal Diabetic Medicine also examines the association of diabetes with Alzheimer’s disease. The authors’ intent was to determine…

“…whether diabetes mellitus influences functional status in patients with Alzheimer’s disease.”

They studied 608 community-dwelling patients with Alzheimer’s disease, assessing diabetes at the beginning. Functional status was examined twice yearly with the Activities of Daily Living scale. Each patient also had a baseline functional disability determined if their Activities of Daily Living score was less than 6. Decreases in these metrics over four years of follow-up exams was used to define worsening of functional disability due to AD. Their data also reveal the ruination of the brain by glucose intolerance:

“At baseline, diabetes was present in 63 participants (10.4%) and, compared with those without diabetes, was associated with functional impairment [age- and sex-adjusted OR = 2.73]. After controlling for confounders, the association remained significant [OR = 2.04]. Follow-up demonstrated a significant interaction between duration of Alzheimer’s disease and diabetes, which was associated with progression of functional impairment in patients who had been diagnosed with Alzheimer’s disease for less than 1 year, but not in those who had been diagnosed with Alzheimer’s disease for more than 1 year. Abnormal one-leg balance, polymedication and obesity seem to be important factors explaining the association between diabetes and functional status.”

Clinicians (non-neurologists), how often do you check one-leg balance? The authors’ data suggests that a year after a clear-cut Alzheimer’s diagnosis the damage is too extensive to discriminate the effect of diabetes, thus they conclude:

“At baseline, the presence of diabetes significantly increases the risk of functional disability in patients with Alzheimer’s disease; our longitudinal data confirm that in patients with a recent diagnosis of Alzheimer’s disease (but not in those who have had Alzheimer’s disease for longer than 1 year), diabetes continues to worsen functional status.”

Regarding mechanisms, an interesting paper just published in Current Diabetes Reviews examines recent findings illuminating the link between IGF-1 signaling and diabetes-associated dementia. The authors state:

“Patients with type 2 diabetes (T2DM) have a two- to three-fold increased risk for Alzheimer’s disease (AD), the most common form of dementia. Vascular complications might explain partially the increased incidence of neurodegeneration in patients with T2DM. Alternatively, neuronal resistance for insulin/insulin-like growth factor-1 (IGF-1) might represent a molecular link between T2DM and AD, characterizing AD as “brain-type diabetes”.”

They describe recent research findings that suggest decreased IGF-1 signaling (IIS) in the brain is a compensatory attempt to reduce the accumulation of toxic β-amyloid (Aβ):

“According to this hypothesis, brains from AD patients showed substantially downregulated expression of the Insulin receptor (IR), the IGF-1 receptor (IGF-1R), and the insulin receptor substrate (IRS) proteins…suggesting that decreased IIS [insulin/IGF-1 signaling] might be involved in the pathogenesis of both T2DM and AD. In contrast, type 2 diabetic patients suffering from AD accumulate less β-amyloid (Aβ) compared to non-diabetic AD patients raising the question, whether the changes in IIS are cause, consequence, or compensatory counterregulation to neurodegeneration. Recent data in C. elegans showed that reducing IIS decreases Aβ toxicity. This effect is accomplished via two transcription factors…suggesting that Insulin/IGF-1 transmitted signals influence Aβ proteotoxicity.”

This important point should not go unnoticed by those who are contemplating therapies that increase IGF-1—they may increase risk factors for Alzheimer’s disease and dementia.

And another paper recently published in Neurology highlights the damage done to the brain by advanced glycation end products due to poor glucose tolerance. The authors observe:

“Several studies report that diabetes increases risk of cognitive impairment; some have hypothesized that advanced glycation end products (AGEs) underlie this association. AGEs are cross-linked products that result from reactions between glucose and proteins. Little is known about the association between peripheral AGE concentration and cognitive aging.”

They studied 920 elders without dementia, 495 with diabetes and 425 with normal glucose, and examined baseline AGE concentration by urine pentosidine in association with performance on the Modified Mini-Mental State Examination (3MS) and Digit Symbol Substitution Test (DSST) at baseline and repeatedly over 9 years. What did the data show?

“On both tests, there was a more pronounced 9-year decline in those with high and mid pentosidine level [more AGEs] compared to those in the lowest tertile. Incident cognitive impairment was higher in those with high or mid pentosidine level than those in the lowest tertile.”

We are probably just beginning to understand the ways that glucose and insulin regulation, whose profound leverage on the physiology is evolutionarily preserved from relatively primitive organisms to humans, has on the brain. Regarding damage done by excessive glucose interaction with tissues, it is not necessary for glucose dysregulation to have progressed to diabetes as the authors conclude:

“High peripheral AGE level is associated with greater cognitive decline in older adults with and without diabetes.”

 

Hormesis: a critical principle for clinical management, weight loss and healthy aging

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Biological systems respond differently to high and low amounts of the same substances and to continuous and intermittent application of the same stimuli. Hormesis is very important to understand for designing programs for medical treatment, exercise, weight loss and more. As stated in a paper published in the journal Ageing Research Reviews:

“Hormesis is a term used by toxicologists to refer to a biphasic dose–response to an environmental agent characterized by a low dose stimulation or beneficial effect and a high dose inhibitory or toxic effect. In the fields of biology and medicine hormesis is defined as an adaptive response of cells and organisms to a moderate (usually intermittent) stress. Examples include ischemic preconditioning, exercise, dietary energy restriction and exposures to low doses of certain phytochemicals.”

In other words, something that can be damaging or toxic at a higher dose may elicit a beneficial response at a lower one. This applies to calorie restriction and exercise as well as medicines. Research on hormesis has advanced in the past decade:

“Recent findings have elucidated the cellular signaling pathways and molecular mechanisms that mediate hormetic responses which typically involve enzymes such as kinases and deacetylases, and transcription factors such as Nrf-2 and NF-κB. As a result, cells increase their production of cytoprotective and restorative proteins including growth factors, phase 2 and antioxidant enzymes, and protein chaperones.

Thus plants from vegetables to wine grapes subject to moderate stress produce a richer yield of beneficial substances, and…

“A better understanding of hormesis mechanisms at the cellular and molecular levels is leading to and to novel approaches for the prevention and treatment of many different diseases.”

Intermittent caloric restriction is emerging as an effective and practical method for  successful long term weight loss and the longevity promoting effects of diet (see the earlier post on intermittent versus continuous calorie restriction and weight loss). Understanding the principle of hormesis is at the core of the Lapis Light Program for Weight Loss and Gene Modulation. As stated in another paper in the same journal:

“Reducing energy intake by controlled caloric restriction or intermittent fasting increases lifespan and protects various tissues against disease, in part, by hormesis mechanisms that increase cellular stress resistance.”

Regarding brain health in particular the author of another paper notes:

“It is likely that the capacity of the brain to remain healthy during aging depends upon its ability to adapt and nurture in response to environmental challenges. In these terms, main principles involved in hormesis can be also applied to understand relationships at a higher level of complexity such as those existing between the CNS and the environment.”

And yet another paper on aging in general beautifully articulates the practical meaning of hormesis:

“Hormesis in aging is represented by mild stress-induced stimulation of protective mechanisms in cells and organisms resulting in biologically beneficial effects. Single or multiple exposure to low doses of otherwise harmful agents, such as irradiation, food limitation, heat stress, hypergravity, reactive oxygen species and other free radicals have a variety of anti-aging and longevity-extending hormetic effects. Detailed molecular mechanisms that bring about the hormetic effects are being increasingly understood, and comprise a cascade of stress response and other pathways of maintenance and repair. Although the extent of immediate hormetic effects after exposure to a particular stress may only be moderate, the chain of events following initial hormesis leads to biologically amplified effects that are much larger, synergistic and pleiotropic. A consequence of hormetic amplification is an increase in the homeodynamic space of a living system in terms of increased defence capacity and reduced load of damaged macromolecules. Hormetic strengthening of the homeodynamic space provides wider margins for metabolic fluctuation, stress tolerance, adaptation and survival. Hormesis thus counter-balances the progressive shrinkage of the homeodynamic space, which is the ultimate cause of aging, diseases and death. Healthy aging may be achieved by hormesis through mild and periodic, but not severe or chronic, physical and mental challenges, and by the use of nutritional hormesis incorporating mild stress-inducing molecules called hormetins. The established scientific foundations of hormesis are ready to pave the way for new and effective approaches in aging research and intervention.”

An interesting paper published in the journal Molecular Neurobiology examines the hormetic effects of caloric restriction on the extremely important process of neuroplasticity.

“Aging is associated with the decline of cognitive properties. This situation is magnified when neurodegenerative processes associated with aging appear in human patients. Neuronal synaptic plasticity events underlie cognitive properties in the central nervous system.”

The authors comment on the hormetic effects of intermittent caloric restriction on the aging brain and nervous system:

“Caloric restriction (CR; either a decrease in food intake or an intermittent fasting diet) can extend life span and increase disease resistance. Recent studies have shown that CR can have profound effects on brain function and vulnerability to injury and disease. Moreover, CR can stimulate the production of new neurons from stem cells (neurogenesis) and can enhance synaptic plasticity, which modulate pain sensation, enhance cognitive function, and may increase the ability of the brain to resist aging.”

As in all other systems of the body…

“The beneficial effects of CR appear to be the result of a cellular stress response stimulating the production of proteins that enhance neuronal plasticity and resistance to oxidative and metabolic insults; they include neurotrophic factors, neurotransmitter receptors, protein chaperones, and mitochondrial biosynthesis regulators.”

The authors of a paper published in the journal Neurochemical Research also consider the role of hormesis in neuroprotection and brain aging.

“The predominant molecular symptom of aging is the accumulation of altered gene products. Moreover, several conditions including protein, lipid or glucose oxidation disrupt redox homeostasis and lead to accumulation of unfolded or misfolded proteins in the aging brain. Alzheimer’s and Parkinson’s diseases or Friedreich ataxia are neurological diseases sharing, as a common denominator, production of abnormal proteins, mitochondrial dysfunction and oxidative stress, which contribute to the pathogenesis of these so called “protein conformational diseases”. The central nervous system has evolved the conserved mechanism of unfolded protein response to cope with the accumulation of misfolded proteins. As one of the main intracellular redox systems involved in neuroprotection, the vitagene system is emerging as a neurohormetic potential target for novel cytoprotective interventions. Vitagenes encode for cytoprotective heat shock proteins (Hsp) Hsp70 and heme oxygenase-1, as well as thioredoxin reductase and sirtuins.”

Furthermore…

“Nutritional studies show that ageing in animals can be significantly influenced by dietary restriction. Thus, the impact of dietary factors on health and longevity is an increasingly appreciated area of research. Reducing energy intake by controlled caloric restriction or intermittent fasting increases lifespan and protects various tissues against disease.”

A fascinating study recently published in the Journal of Surgical Research examines the hormetic benefits of short-term preoperative caloric restriction on the response to surgical trauma. The authors state:

“Lifespan extension is achieved through long-term application of dietary restriction (DR), and benefits of short-term dietary restriction on acute stress and inflammation have been observed….We hypothesized that short-term DR in humans reduces the acute phase response following a well defined surgical trauma.”

They randomized thirty live kidney donors to either 30% preoperative dietary restriction followed by 1 d of fasting or a 4 d ad libitum diet prior to surgery. In addition to white blood cell subsets and numbers, they measured serum cytokine production after stimulation of whole blood with lipopolysaccharide (LPS). An excellent response to short-term caloric restriction was documented:

“A clear trend towards lower numbers of postoperative circulating leukocytes was observed in the DR group. IL-8 serum levels were significantly higher in the DR group over the first 6 postoperative days. After LPS stimulation, significantly less TNF-α was produced by blood obtained postoperatively compared with preoperative blood from the DR group. This was not observed in the control group.”

In other words, the short-term caloric restriction group expressed a much ‘better’ (less damaging) inflammatory response to surgical trauma compared to the control group. This begs for more research into the adoption of short-term or intermittent caloric restriction as the standard of care in preparation for surgery.

The phenomenon of hormesis in biology is a vast subject that every clinician must be familiar with to most effectively calibrate the dose of a wide range of interventions from medicines and supplements to exercise, caloric restriction and therapies that stimulate the body by the use of hands, needles or any other sensory-based modality—even subtle aspects of counseling and imagery. It is fundamental to our system of weight loss and gene modulation.

The advantages of intermittent versus continuous calorie restriction for long term weight loss

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There is an accumulation of fascinating scientific evidence that intermittent calorie restriction (ICR) offers a number of advantages over continuous calorie restriction (CCR) for successful long term weight loss and the ‘turning on’ of genes that favor longevity. Consider a study published recently in the International Journal of Obesity in which the investigators compared ICR and CCR for weight loss and metabolic disease risk markers in overweight women. The authors state:

“Excess weight and weight gain during adult life increases the risk of several diseases including diabetes, cardiovascular disease (CVD), dementia, certain forms of cancer including breast cancer, and can contribute to premature death. Observational and some randomised trials indicate that modest weight reduction (>5% of body weight) reduces the incidence and progression of many of these diseases. Although weight control is beneficial, the problem of poor compliance in weight loss programmes is well known.”

Moreover…

“Even where reduced weights are maintained, many of the benefits achieved during weight loss, including improvements in insulin sensitivity, may be attenuated due to non-compliance or adaptation. Sustainable and effective energy restriction strategies are thus required.”

In other words, a method that can be comfortable enough to be accepted into daily life for the long that also avoids loss of improvements due to adaption is required.

“One possible approach may be intermittent energy restriction (IER), with short spells of severe restriction between longer periods of habitual energy intake. For some subjects such an approach may be easier to follow than a daily or continuous energy restriction (CER) and may overcome adaption to the weight reduced state by repeated rapid improvements in metabolic control with each spell of energy restriction.”

So the authors set out to…

“…compare the feasibility and effectiveness of IER with CER for weight loss, insulin sensitivity and other metabolic disease risk markers…This is the largest randomised comparison of an isocalorific intermittent vs. continuous energy restriction to date in free living humans..”

They designed a randomised comparison of a 25% energy restriction as IER (~2266 kJ/day which equals 541 calories per day for 2 days/week) or CER (~6276 kJ/day equaling 1499 calories each day for 7 days/week) in 107 overweight or obese premenopausal women for a 6 month study period. They measured an extensive list of biomarkers at baseline and after 1, 3 and 6 months: weight, anthropometry (size, weight and proportions), biomarkers for breast cancer, diabetes, cardiovascular disease and dementia risk; insulin resistance (HOMA), oxidative stress markers, leptin, adiponectin, IGF-1 and IGF binding proteins 1 and 2, androgens, prolactin, inflammatory markers (high sensitivity C-reactive protein and sialic acid), lipids, blood pressure and brain derived neurotrophic factor. What did the data show?

“Last observation carried forward analysis showed IER and CER are equally effective for weight loss, mean weight change for IER was −6.4 kg vs. −5.6 kg for CER. Both groups experienced comparable reductions in leptin, free androgen index, high sensitivity C-reactive protein, total and LDL cholesterol, triglycerides, blood pressure and increases in sex hormone binding globulin, IGF binding proteins 1 and 2. Reductions in fasting insulin and insulin resistance were modest in both groups, but greater with IER than CER; difference between groups for fasting insulin −1.2 μU/ml, and insulin resistance −1.2 μU/mmol/L.”

Regarding concerns about tolerance…

“A recent blinded trial of a 2 day VLCD [very low calorie diet] (1311 kJ/day [313 calories per day!]) reported no adverse effects on cognition, energy levels, sleep or mood, suggesting symptoms are expected with VLCD and therefore experienced and could potentially be overcome with appropriate counselling. Importantly IER did not lead to overeating on non-VLCD days.”

The authors briefly summarize the results of their comparison of IER and CER by concluding:

“IER is as effective as CER in regards to weight loss, insulin sensitivity and other health biomarkers and may be offered as an alternative equivalent to CER for weight loss and reducing disease risk.”

That’s not all though. The authors additionally note an extremely interesting observation with profound implications and potential for benefit regarding additional benefits of an intermittent very low calorie method:

“Recent reviews speculate that IER may be associated with greater disease prevention than CER due to increased cellular stress resistance, in particular increased resistance to oxidative stress. This is thought to be mediated by ‘hormesis’ whereby the moderate stress of energy restriction increases the production of cytoprotective, restorative proteins, antioxidant enzymes and protein chaperones. Alternate day fasting has been linked to increased SIRT-1 gene expression in muscle, and to greater neuronal resistance to injury compared to CER in C57BL/6 mice. The tendency for greater improvements in oxidative stress markers in our IER than in the CER group may support these assertions. Declines in long term protein oxidation product aggregates suggest IER as a possible activator of catabolism and autophagy.”

In other words, intermittent calorie restriction can be as effective as continuous calorie restriction for weight loss, but have the added advantage of ‘turning on’ genes beneficial for health and longevity and preventing adaptation that would result in regaining weight.

Other investigators also have compared intermittent with continuous calorie (daily) calorie restriction as in a study published recently in the journal Obesity Reviews. The authors set out to…

“…evaluate and compare the effects of daily CR versus intermittent CR on weight loss, fat mass loss, lean mass retention and visceral fat mass reduction, in overweight and obese adults.”

They undertook a review of studies that were randomized control trials, had a primary endpoint of weight loss and/or body composition changes, used daily CR or intermittent CR as the primary focus of the intervention; had a study duration of 4–24 weeks, and involved adult populations who were overweight or obese subjects but not diabetic. These included 11 daily continuous calorie restriction trials and five intermittent CR trials published between 2000 and 2010, along with two unpublished trials of intermittent CR from their own lab. What did all these studies add up to?

“Results reveal similar weight loss and fat mass loss with 3 to 12 weeks’ intermittent CR (4–8%, 11–16%, respectively) and daily CR (5–8%, 10–20%, respectively). In contrast, less fat free mass was lost in response to intermittent CR versus daily CR.”

This is a significant advantage of ICR over CCR (continuous = daily calorie restriction). The authors conclude by stating:

“In sum, intermittent CR and daily CR diets appear to be equally as effective in decreasing body weight, fat mass, and potentially, visceral fat mass. However, intermittent restriction regimens may be superior to daily restriction regimens in that they help conserve lean mass at the expense of fat mass. These findings add to the growing body of evidence showing that intermittent CR may be implemented as another viable option for weight loss in overweight and obese populations.”

Numerous other studies have examined the distinctive benefits of intermittent calorie restriction. A paper published recently in the journal Oncogene investigates the positive effects of brief ICR compared to CCR for cancer patients. The authors state:

“The dietary recommendation for cancer patients receiving chemotherapy, as described by the American Cancer Society, is to increase calorie and protein intake. Yet, in simple organisms, mice, and humans, fasting—no calorie intake—induces a wide range of changes associated with cellular protection, which would be difficult to achieve even with a cocktail of potent drugs. In mammals, the protective effect of fasting is mediated, in part, by an over 50% reduction in glucose and insulin-like growth factor 1 (IGF-I) levels.”

They point out that cancer cells are unable to respond to the positive stimuli of calorie restriction:

“Because proto-oncogenes function as key negative regulators of the protective changes induced by fasting, cells expressing oncogenes, and therefore the great majority of cancer cells, should not respond to the protective signals generated by fasting, promoting the differential protection (differential stress resistance) of normal and cancer cells.”

Moreover…

“Preliminary reports indicate that fasting for up to 5 days followed by a normal diet, may also protect patients against chemotherapy without causing chronic weight loss. By contrast, the long-term 20 to 40% restriction in calorie intake (dietary restriction, DR), whose effects on cancer progression have been studied extensively for decades, requires weeks–months to be effective, causes much more modest changes in glucose and/or IGF-I levels, and promotes chronic weight loss in both rodents and humans.”

They go on to review studies on fasting, cellular protection and chemotherapy resistance, and futher compare them to those on continuous calorie restriction and cancer treatment. The authors conclude:

“Although additional pre-clinical and clinical studies are necessary, fasting has the potential to be translated into effective clinical interventions for the protection of patients and the improvement of therapeutic index.”

A study published in the Journal of Molecular and Cellular Cardiology offers evidence that intermittent calorie restriction activates genes that help in the recovery from heart damage. The authors state:

“Chronic heart failure (CHF) is the major cause of death in the developed countries. Calorie restriction is known to improve the recovery in these patients; however, the exact mechanism behind this protective effect is unknown. Here we demonstrate the activation of cell survival PI3kinase/Akt and VEGF pathway as the mechanism behind the protection induced by intermittent fasting in a rat model of established chronic myocardial ischemia (MI).“

Two weeks after myocardial ischemia was induced in their study animals, they were randomly assigned to a normal feeding group (MI-NF) and an alternate-day feeding group (MI-IF). After 6 weeks the authors evaluated the effect of intermittent fasting on cellular and ventricular remodeling and long-term survival. The results were truly striking:

“Compared with the normally fed group, intermittent fasting markedly improved the survival of rats with CHF (88.5% versus 23% survival). The heart weight body weight ratio was significantly less in the MI-IF group compared to the MI-NF group (3.4 ± 0.17 versus 3.9 ± 0.18. Isolated heart perfusion studies exhibited well preserved cardiac functions in the MI-IF group compared to the MI-NF group. Molecular studies revealed the upregulation of angiogenic factors such asHIF-1-α (3010 ± 350% versus 650 ± 151%), BDNF (523 ± 32% versus 110 ± 12%), and VEGF (450 ± 21% versus 170 ± 30%) in the fasted hearts. Immunohistochemical studies confirmed increased capillary density in the border area of the ischemic myocardium and synthesis VEGF by cardiomyocytes. Moreover fasting also upregulated the expression of other anti-apoptotic factors such as Akt and Bcl-2 and reduced the TUNEL positive apoptotic nuclei in the border zone.”

This is a dramatic indication that intermittent calorie restriction can be used to protect and repair heart tissue. The authors conclude:

“Chronic intermittent fasting markedly improves the long-term survival after CHF by activation through its pro-angiogenic, anti-apoptotic and anti-remodeling effects.”

Another fascinating study published recently in the journal Cancer Prevention Research demonstrates that intermittent calorie restriction is clearly superior to both continuous calorie restriction and an unrestricted diet for breast cancer prevention. Specifically, the authors studied…

“The effect of chronic (CCR) and intermittent (ICR) caloric restriction on serum adiponectin and leptin levels…in relation to mammary tumorigenesis.”

Their subjects were assigned to ad libitum fed, ICR (3-week 50% caloric restriction followed by 3-wks 100% AL consumption), and CCR groups.

“Mammary tumor incidence was 71.0%, 35.4%, and 9.1% for AL, CCR, and ICR mice, respectively. Serum adiponectin levels were similar among groups with no impact of either CCR or ICR. Serum leptin level rose in AL mice with increasing age but was significantly reduced by long-term CCR and ICR. The ICR protocol was also associated with an elevated adiponectin/leptin ratio. In addition, ICR-restricted mice had increased mammary tissue AdipoR1 expression and decreased leptin and ObRb expression compared with AL mice. Mammary fat pads from tumor-free ICR-mice had higher adiponectin expression than AL and CCR mice whereas all tumor-bearing mice had weak adiponectin signal in mammary fat pad.”

This amounts to an impressive ‘turning on’ of genes that protect against breast cancer for ICR. In conclusion…

“…we did find that reduced serum leptin and elevated adiponectin/leptin ratio were associated with the protective effect of intermittent calorie restriction.”

A paper published in the journal Nutrition and Cancer demonstrates that ICR offers a greater protective effect than CCR for prostate cancer. The authors state:

“Prostate cancer is the most frequently diagnosed cancer in men. Whereas chronic calorie restriction (CCR) delays prostate tumorigenesis in some rodent models, the impact of intermittent caloric restriction (ICR) has not been determined. Here, transgenic adenocarcinoma of the mouse prostate (TRAMP) mice were used to compare how ICR and CCR affected prostate cancer development.”

Their animal models for prostate cancer were assigned to ad libitum (AL), ICR, and CCR groups. There were distinctive differences according to the manner of calorie restriction that dramatically favored the ICR over both the AL and CCR cohorts:

“ICR mice were older at tumor detection than AL and CCR mice. There was no difference for age of tumor detection between AL and CCR mice. Similar results were found for survival. Serum leptin, adiponectin, insulin, and IGF-I were all significantly different among the groups.”

Not only did the subjects on CCR live longer with healthier biomarkers than the ones on either the free diet or CCR, there was no difference between the AL and CCR groups for age of tumor detection or survival. The implication is exciting: the benefits were due not to the weight loss component but to the way in which ICR affects gene expression. The authors conclude:

“These results indicate that the way in which calories are restricted impacts both time to tumor detection and survival in TRAMP mice, with ICR providing greater protective effect compared to CCR.”

A paper published in the The Journal of Nutritional Biochemistry also offers evidence that intermittent calorie restriction protects heart tissue:

“It has been reported that dietary energy restriction, including intermittent fasting (IF), can protect heart and brain cells against injury and improve functional outcome in animal models of myocardial infarction (MI) and stroke. Here we report that IF improves glycemic control and protects the myocardium against ischemia-induced cell damage and inflammation in rats.”

The authors showed by echocardiographic analysis of heart structur and function that intermittent fasting attenuates the disease related increase in heart thickness, end systolic and diastolic volumes, and ejection fraction. Additionally…

“The size of the ischemic infarct 24 h following permanent ligation of a coronary artery was significantly smaller, and markers of inflammation (infiltration of leukocytes in the area at risk and plasma IL-6 levels) were less, in IF rats compared to rats on the control diet. IF resulted in increased levels of circulating adiponectin prior to and after MI.”

There is now a large body of evidence showing that ICR increases the protective hormone adiponectin much more than CCR. The authors conclude:

“Because recent studies have shown that adiponectin can protect the heart against ischemic injury, our findings suggest a potential role for adiponectin as a mediator of the cardioprotective effect of IF.”

A paper published in the journal Ageing Research Reviews discusses how IFR and CCR can protect the brain from accelerated neurodegeneration associated with aging. The authors note:

“The vulnerability of the nervous system to advancing age is all too often manifest in neurodegenerative disorders such as Alzheimer’s and Parkinson’s diseases. In this review article we describe evidence suggesting that two dietary interventions, caloric restriction (CR) and intermittent fasting (IF), can prolong the health-span of the nervous system by impinging upon fundamental metabolic and cellular signaling pathways that regulate life-span.”

As we’ve seen regarding cardioprotection and tumorigenesis…

“CR and IF affect energy and oxygen radical metabolism, and cellular stress response systems, in ways that protect neurons against genetic and environmental factors to which they would otherwise succumb during aging. There are multiple interactive pathways and molecular mechanisms by which CR and IF benefit neurons including those involving insulin-like signaling, FoxO transcription factors, sirtuins and peroxisome proliferator-activated receptors. These pathways stimulate the production of protein chaperones, neurotrophic factors and antioxidant enzymes, all of which help cells cope with stress and resist disease.”

These studies comprise the first post that illustrates the scientific basis for the Lapis Light Weight Loss & Gene Modulation Program that customizes intermittent calorie restriction according to the individual’s weight management and other health needs. Subsequent posts will offer additional scientific evidence important for other aspects of the program.

How much alcohol is a healthy dose for women?

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A study just published in PloS Medicine (Public Library of Science) offers more evidence that alcohol consumed in moderation can promote overall health and successful aging for women. The data presented also helps to firm up guidelines for determining amounts that are beneficial and harmful. The authors state:

“Observational studies have documented inverse associations between moderate alcohol consumption and risk of premature death. It is largely unknown whether moderate alcohol intake is also associated with overall health and well-being among populations who have survived to older age. In this study, we prospectively examined alcohol use assessed at midlife in relation to successful ageing in a cohort of US women.”

They defined “successful ageing” as being free of 11 major chronic diseases and having no major cognitive impairment, physical impairment, or mental health limitations, and applied this to the 13,894 Nurses’ Health Study participants who survived to age 70 or older for whom they had comprehensive and continuously updated health data. This was correlated with habits of alcohol consumption. Their data paints an interesting picture:

“…light-to-moderate alcohol consumption at midlife was associated with modestly increased odds of successful ageing. The odds ratios were 1.0 (referent) for nondrinkers, 1.11 for ≤5.0 g/d, 1.19 for 5.1–15.0 g/d, 1.28 for 15.1–30.0 g/d, and 1.24 for 30.1–45.0 g/d. Meanwhile, independent of total alcohol intake, participants who drank alcohol at regular patterns throughout the week, rather than on a single occasion, had somewhat better odds of successful ageing; for example, the odds ratios were 1.29 and 1.47 for those drinking 3–4 days and 5–7 days per week in comparison with nondrinkers, respectively, whereas the odds ratio was 1.10 for those drinking only 1–2 days per week.”

In other words, consuming 30 to 45 grams of alcohol per day conferred a 24% increase in the odds for successful aging. Moreover, drinking 5-7 days per week increased the odds of a good outcome by 47%. The authors conclude:

“These data suggest that regular, moderate consumption of alcohol at midlife may be related to a modest increase in overall health status among women who survive to older ages.”

So how much is 30 to 45 grams of alcohol? A ‘standard drink‘ = 10 grams of pure alcohol. A 750 ml (regular size) bottle of red wine with a typical 14% alcohol volume equals approximately 8.3 standard drinks (82.8 grams of pure alcohol). A 30 ml (one ounce) shot of 80 proof (40% alcohol volume) is 9.4 grams of pure alcohol (just shy of one standard drink). An ounce of stronger spirits like 94 proof gin or vodka is 11.12 grams of pure alcohol.

 

Green tea polyphenols protect against sunburn and improve skin quality

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Skin protection strategies during sun-drenched activities while minimizing vitamin D attenuating sunscreens can include green tea polyphenols according to a study recently published in The Journal of Nutrition. The authors first observe:

“Dietary constituents including polyphenols and carotenoids contribute to endogenous photoprotection and modulate skin characteristics related to structure and function of the tissue. Animal and in-vitro studies indicate that green tea polyphenols affect skin properties.”

They performed a 12-wk, double-blind, placebo-controlled study during which 60 female volunteers consumed either a beverage with green tea polyphenols or a control drink. During the study they measured skin photoprotection, structure, and function at baseline, 6 weeks and 12 weeks.  Their data showed  impressive benefits:

“Following exposure of the skin areas to 1.25 minimal erythemal dose of radiation from a solar simulator, UV-induced erythema decreased significantly in the intervention group by 16 and 25% after 6 and 12 wk, respectively. Skin structural characteristics that were positively affected included elasticity, roughness, scaling, density, and water homeostasis.”

Additionally…

“Intake of the green tea polyphenol beverage for 12 wk increased blood flow and oxygen delivery to the skin. Likewise, in a separate, randomized, double-blind, single-dose (0.5, 1.0, and 2.0 g) study of green tea polyphenols, blood flow was maximized at 30 min after ingestion.”

The green tea polyphenol beverage used in the study provided a dose of 1402 mg total catechins per day. Because the average 6 ounce cup of green tea contains between 50 and 100 mg of catechins and can vary widely depending on the tea and other factors, taking green tea polyphenols in a reliable supplemental form is more practical than attempting to drink  fifteen or more cups of tea. There is no good reason why the authors’ conclusion does not also apply to men:

“In summary, green tea polyphenols delivered in a beverage were shown to protect skin against harmful UV radiation and helped to improve overall skin quality of women.”

While generally safe, because there is some evidence that green tea catechins may enhance the Th2 (humoral) immune response, clinicians should bear this in mind and individuals receiving treatment for Th2-dominant autoimmune disorders should discuss the use of green polyphenols with their provider.

The highest amounts of calcium intake increase the risk of fracture

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Patients are often surprised to learn that osteoporosis is not a calcium deficiency disorder but rather a failure to maintain the microarchitecture of the bone of which the protein matrix is a critical component. Moreover, earlier posts on magnesium and calcium have document the pro-inflammatory potential of calcium supplementation. Now fascinating research just published in the British Medical Journal offers evidence that calcium above the lowest quintile does not improve the risk of fracture of any type, while the highest levels actually increase the risk of fracture. The authors set out to…

“……investigate associations between long term dietary intake of calcium and risk of fracture of any type, hip fractures, and osteoporosis.”

They note that confusion regarding the issue of calcium requirements has been…

“…reflected by the wide range of daily calcium recommendations for individuals older than 50 years: at present 700 mg in the UK, 800 mg in Scandinavia, 1200 mg in the United States, and 1300 mg in Australia and New Zealand.”

The authors investigated 61,433 women born between 1914 and 1948 for 19 years for correlations between dietary intake of calcium and fractures of any type, hip fractures, and osteoporosis. They took into consideration vitamin D consumption, hormonal status, and other pertinent biological and lifestyle factors including physical activity. Perhaps not surprisingly in light of other evidence that has emerged recently about calcium, their data challenges the conventional wisdom:

“These findings show an association between a low habitual dietary calcium intake (lowest quintile) and an increased risk of fractures and of osteoporosis. Above this base level, we observed only minor differences in risk. The rate of hip fracture was even increased in those with high dietary calcium intakes.“

In others, amounts higher than the lowest level of calcium intake adequate to avoid gross insufficiency and compromised bone micoarchitecture there were not only no significant benefits, the highest levels of intake increased fracture risk. The authors comment:

“The present results may reflect a situation when a moderate intake of calcium* combined with adequate intake of other micronutrients is sufficient to meet the structural and functional demands of the skeleton. High levels of intake did not further decrease the rate of fracture, and might even increase the rate of hip fractures…Moreover, use of supplemental calcium has been associated with higher rates of hip fracture both in a cohort study and in randomised controlled trials…Furthermore, high calcium doses slow bone turnover and also reduce the number of active bone remodelling sites. This situation can lead to a delay of bone repair caused by fatigue, and thus increase the risk of fractures independent of bone mineral density.”

*Their data indicate that a total dietary intake of 700 mg of calcium per day is sufficient to prevent fracture and osteoporosis. The authors conclude:

“Incremental increases in calcium intake above the level corresponding to the first quintile of our female population were not associated with a further reduction of osteoporotic fracture rate.”

Considering that chronic inflammation can be a primary factor in causing loss of the protein ‘scaffolding’ of bone responsible for strength, resilience, and the matrix to which minerals attach, these findings invoke recollection of the recent evidence that calcium supplementation can increase the inflammation of  cardiovascular disease. In case you missed it, a recent research paper published in the British Medical Journal follows up on earlier reports of this association. The authors’ intent was…

“To investigate the effects of personal calcium supplement use on cardiovascular risk in the Women’s Health Initiative Calcium/Vitamin D Supplementation Study (WHI CaD Study), using the WHI dataset, and to update the recent meta-analysis of calcium supplements and cardiovascular risk.”

The examined the data from a randomised, placebo controlled trial of calcium alone or with vitamin D in 36,282 postmenopausal women over seven years for myocardial infarction, coronary revascularisation, death from coronary heart disease, and stroke. The data told an interesting story:

“In the WHI CaD Study there was an interaction between personal use of calcium supplements and allocated calcium and vitamin D for cardiovascular events…Calcium or calcium and vitamin D increased the risk of myocardial infarction (relative risk 1.24 (1.07 to 1.45), P=0.004) and the composite of myocardial infarction or stroke (1.15 (1.03 to 1.27), P=0.009).”

Clinicians and patients need to appreciate that inflammation, a fundamental causal factor in both osteoporosis and cardiovascular disease, can be made worse by calcium supplements. The authors conclude:

“Calcium supplements with or without vitamin D modestly increase the risk of cardiovascular events, especially myocardial infarction, a finding obscured in the WHI CaD Study by the widespread use of personal calcium supplements. A reassessment of the role of calcium supplements in osteoporosis management is warranted.“

 

Pro-aging signaling, cancer and diabetes are reduced with LESS growth hormone effect

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Research just published in the journal Science Translational Medicine is a further reminder of the critical need  for caution and sound physiological thinking when considering the use of growth hormone. The authors note in their introduction:

“Reduced activity of growth hormone (GH) and insulin-like growth factor–1 (IGF-1) signaling proteins or of their orthologs in nonhuman organisms…contribute to extended life span and protection against age-dependent damage or diseases…”

Pursuant to these earlier observations they formulated an important investigative objective:

“Mutations in growth signaling pathways [that diminish the GH effect] extend life span, as well as protect against age-dependent DNA damage in yeast and decrease insulin resistance and cancer in mice. To test their effect in humans, we monitored for 22 years Ecuadorian individuals who carry mutations in the growth hormone receptor (GHR) gene that lead to severe GHR and IGF-1 (insulin-like growth factor–1) deficiencies.”

Combining this information with surveys that identified the cause and age of death for their subjects who died before this period, the data paint a compelling picture:

“The individuals with GHR deficiency exhibited only one nonlethal malignancy and no cases of diabetes, in contrast to a prevalence of 17% for cancer and 5% for diabetes in control subjects.“

They describe earlier studies that help explain the very low incidence of cancer. In one, serum from subjects with GHR deficiency had reduced DNA breakage yet increased apoptosis in human mammary epithelial cells treated with hydrogen peroxide. In others, serum from GHR-deficient subjects caused reduced expression of RAS, PKA (protein kinase A), and TOR (target of rapamycin) and up-regulation of SOD2 (superoxide dismutase 2) in treated cells. These changes in signaling promote cellular protection and life-span extension in model organisms.

Importantly, in their present study the authors also observed:

“……reduced insulin concentrations and a very low HOMA-IR (homeostatic model assessment–insulin resistance) index in individuals with GHR deficiency, indicating higher insulin sensitivity, which could explain the absence of diabetes in these subjects.”

These comments, along with an earlier post on growth hormone research, are a plea for caution along with sound thinking. There seem to be good reasons why we have evolved to reduce growth hormone activity with age. The authors advance the idea that blocking growth hormone receptor function may…

“…prevent or reduce the incidence of cancer, diabetes, and other age-related diseases, including inflammatory disorders, stroke, and neurodegenerative diseases.”

Clinicians and individuals tempted to experiment with growth hormone therapy should consider the authors’ conclusion:

“Our finding that human GHRD [growth hormone receptor deficient] subjects are protected against age-related pathologies is consistent with the elevated cellular protection in both yeast and human cells with reduced expression of specific pro-growth genes and with the effect of serum from GHRD subjects in lowering their expression. The results from the human cohort also show similarities with those from GHRD- and GH-deficient mice, which display lower incidence (49%) or delayed occurrence of fatal neoplasms and increased insulin sensitivity… These results provide evidence for a role of evolutionarily conserved pathways in the control of aging and disease burden in humans.”

Low cholesterol associated with higher mortality

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Most readers here are aware that cholesterol is the substrate for all steroid hormones and a component of all cell membranes, so that when too low it is a contributing factor to a range of disorders. A study just published in the Journal of Epidemiology provides more evidence for the association between low cholesterol and death from all causes. The authors state:

“We investigated the relationship between low cholesterol and mortality and examined whether that relationship differs with respect to cause of death.”

They conducted their study using 12,334 healthy adults from 12 rural areas in Japan. They correlated serum total cholesterol with total mortality, noting sex and cause of death. The average follow-up period was 11.9 years. What did their data show?

“As compared with a moderate cholesterol level (4.14-5.17 mmol/L)[161.5-201.5 mg/dL], the age-adjusted hazard ratio (HR) [risk] of low cholesterol (<4.14 mmol/L)[161.5 mg/dL] for mortality was 1.49 [50% increase in mortality]… High cholesterol (≥6.21 mmol/L)[≥242 mg/dL] was not a risk factor. This association was unchanged in analyses that excluded deaths due to liver disease… The multivariate-adjusted HRs [hazard ratios = risks]…of the lowest cholesterol group for hemorrhagic stroke, heart failure (excluding myocardial infarction), and cancer mortality [were] significantly higher than those of the moderate cholesterol group, for each cause of death.”

Numerous lines of reasoning, documented in a broad accumulation of scientific evidence (of which a small ‘taste’ is reported in this venue) converge on the assertion that inflammation, rather than cholesterol per se, is the primary villain in cardiovascular disease. Clinicians and patients alike should bear in mind the authors’ conclusion:

“Low cholesterol was related to high mortality even after excluding deaths due to liver disease from the analysis. High cholesterol was not a risk factor for mortality.“