Mechanisms of cognitive decline, one of the greatest threats of aging

Posted on April 11, 2010 by Dr. Jonathan

Nature Vol 464 There is a lot being written about the ability of the brain to compensate for age-related changes with enhanced connectivity and efficiency that makes for better judgment and emotional maturity. The sad truth is that the brains of at least 50% of us will have sustained too much damage for this to come to fruition. The authors of an extensive review just published in the journal Nature begin with a statement important for anyone reading this:

“Cognitive frailty is emerging as one of the greatest health threats of the twenty-first century. As the life expectancy of the population has increased, so too has the prevalence of cognitive decline and dementia, largely in the form of Alzheimer’s disease, which now affects almost 50% of adults over the age of 85 in the United States1. This startling figure can only grow as the average age of the population rises, so understanding the basis of cognitive decline during ageing is critical.”

They proceed to describe some of the major categories that define the process of molecular aging as it pertains to cognitive decline, noting that:

“…altered regulation of fundamental mechanisms of ageing may contribute to the pathogenesis of neurodegenerative disorders.”

It is this kind of attention to fundamental mechanisms with a systems biology perspective that is inherent to the functional medicine approach. The authors identify these major factors:

Mitochondrial dysfunction (the ability of brain cells to produce energy to function and repair)
Oxidative damage
Epigenetic changes (changes in genes due to environmental stimuli)
Autophagy and protein turnover (housecleaning)
Insulin signalling

Additionally, they describe the role of the brain as the master regulator of aging throughout the body.

Their list is not complete—there are additional factors that we attend to including neurotransmitter metabolism and receptor sensitivity, fatty acid cell membrane integrity, the role of steroid hormones in the brain, autoimmune inflammation, excess cortisol (stress hormone) production, etc. If you want to be realistic about a strategy for preventing cognitive decline and Alzheimer’s disease, these are the kinds of things that you have to ask you doctor about and make sure they are being attended to.

Acute or critical care hospitilization damages cognitive function in older adults

Posted on March 15, 2010 by Dr. Jonathan

JAMA 022410 This is something to take to heart if you or someone you know require hospital care for an acute or critical illness. This paper just published in The Journal of the American Medical Association presents a study that set out to…

“To determine whether decline in cognitive function was greater among older individuals who experienced acute care or critical illness hospitalizations relative to those not hospitalized and to determine whether the risk for incident dementia differed by these exposures.”

If you have experience with this their conclusion will not surprise you:

“Among a cohort of older adults without dementia at baseline, those who experienced acute care hospitalization and critical illness hospitalization had a greater likelihood of cognitive decline compared with those who had no hospitalization. Noncritical illness hospitalization was significantly associated with the development of dementia.”

Note the last sentence: even noncritical illness hospitalization was associated with dementia. You too may have been distressed to see older folks decline in cognitive function following hospitalization due to depletion of critical internal resources that were already suboptimal, oxidative stress, etc.—and nothing was done to help it (even though functional medicine resources are available). Considering the central role of the brain in regulating all bodily functions, this must be kept in mind when evaluating subsequent health complaints of any kind.

Does your brain seem like it isn’t working as well? This predicts further decline.

Posted on January 27, 2010 by Dr. Jonathan

A study just published in the journal Alzheimer’s & Dementia is a ‘heads-up’ for those who want to avoid cognitive impairment and dementia down the road. The researchers observed 213 subjects over an average of 7 years and documented that those with subjective cognitive impairment (SCI) declined significantly more rapidly to poor brain health and dementia than those with no experience of cognitive impairment. They concluded: “These results indicate that SCI in subjects with normal cognition is a harbinger of further decline in most subjects during a 7-year mean follow-up interval.” Having a little trouble remembering names, where you put your keys, what you came into the room for? Are you learning new things as easily as you did 5 years ago? Don’t wait, determine your brain health strategy now.

Anti-inflammatory diets slow brain aging

Posted on January 14, 2010 by Dr. Jonathan

Here we have important evidence that what we eat has a big effect on how our brain ages. A review of recent studies was published in The Journal of Neuroscience that highlights the importance of slowing down the “age-related neurodegenerative diseases superimposed on a declining nervous system [that] could enhance the motor and cognitive behavioral deficits that normally occur in senescence.” The authors note that drugs are not available, so “it is important to determine what methods can be used today to increase healthy aging [and] forestall the onset of these diseases.” They emphasize the benefit of “diets rich in antioxidants and anti-inflammatory components such as those found in fruits, nuts, vegetables, and spices” to “lower age-related cognitive declines and the risk of developing neurodegenerative disease.” Are you getting what you need to slow the pace of neurodegeneration? The right tests can tell.

Insulin resistance and dementia or Alzheimer’s disease

Posted on November 29, 2009 by Dr. Jonathan

No doubt about it, you have to take care of your blood sugar and insulin to prevent your brain from degenerating. Here are several papers published in prestigious journals that show the strong connection between insulin resistance and dementia or Alzheimer’s disease:

Insulin resistance and cognitive impairment in Archives of Neurology
Hyperinsulinemia and risk of Alzheimer’s disease in Neurology
Insulin resistance and executive dysfunction in the Journal of the American Geriatrics Society
Hyperinsulinemia and Alzheimer’s disease in the journal Age and Ageing
Body mass index, cardiovascular risk factors, and dementia in Archives of Internal Medicine

Testing your levels of hemoglobin A1C, glucose, insulin and triglycerides along with measuring your waist-to-hip ratio are among the ways we can see how you’re doing.

Waist-to-hip ratio in midlife linked to later dementia

Posted on November 24, 2009 by Dr. Jonathan

Factors that place fat around the waist (insulin resistance) and the activity of that fat tissue (production of signaling molecules that promote inflammation) are both at play behind the connection documented recently in this paper published in the journal Neurology. The authors found that “…a midlife WHR [waist hip ratio] greater than 0.80 increased risk for dementia approximately twofold…,” and conclude: “There are midlife and late-life implications for dementia prevention, and analytical considerations related to identifying risk factors for dementia.” Here are a few more papers related to the same finding:

Research on diabetes, hyperinsulinemia and dementia in Dementia and Geriatric Disorders
A paper on abdominal obesity and Alzheimer Disease published in the same journal
A study in Archives of Neurology that concludes: “A larger WHR may be related to neurodegenerative, vascular, or metabolic processes that affect brain structures underlying cognitive decline and dementia.”

Advanced dementia is a terminal condition

Posted on October 29, 2009 by Dr. Jonathan

This paper in the New England Journal of Medicine details the clinical course of advanced dementia. It is a terminal condition. Whatever your age, now is the time to have a sound, evidence-based strategy for taking care of your brain.

Alzheimer’s & the Adrenal Circadian Rhythm

Posted on October 12, 2009 by Dr. Jonathan

Dementia begins in the hippocampus, the part of the brain that converts short to long-term memory. It is also responsible for regulating the daily rhythm of cortisol secretion by the adrenal glands. This paper is one of a number that recognize abnormalities in the cortisol curve (the graph in your adrenal report) as an early screen for dementia. This is important to address as early as possible. When the neurons are gone, they’re gone forever!

Homocysteine and Brain Atrophy

Posted on October 12, 2009 by Dr. Jonathan

Homocysteine is a powerful risk factor for cardiovascular disease. Many of you have had it checked in your screening blood test for that reason, and because it is a nutritional marker for the vital process called methylation. Not surprisingly, we now have evidence that even smaller elevations of homocysteine are associated with neurodegeneration bad enough to cause brain shrinkage. Low stomach acid, estrogen supplementation and birth control pills are common causes of elevated homocysteine.

Diabetes and Dementia

Posted on October 8, 2009 by Dr. Jonathan

This interesting study demonstrated a distinct damage to the brain tissue of diabetic individuals with dementia. The kind of damage differed according to whether the diabetes was treated or not. Individuals with dementia plus diabetes had more inflammation in the brain than those without diabetes. Remember that damage done by insulin resistance begins long before diabetes is diagnosed; and medications like metformin, while reducing blood glucose, don’t reduce inflammation.