Original research published recently in the Annals of Internal Medicine offers evidence that trans-palmitoleate, a fat present in milk, is responsible for metabolic benefits observed with dairy consumption. The authors set out to…
“…To investigate whether circulating trans-palmitoleate is independently related to lower metabolic risk and incident type 2 diabetes.”
They examined 3736 adults in the Cardiovascular Health Study for plasma phospholipid fatty acids, blood lipids, inflammatory markers, and glucose–insulin and dietary habits, taking into consideration relevant demographic, clinical, and lifestyle factors. They then determined how trans-palmitoleate related to major metabolic risk factors. Their data tell an interesting story of a helpful fat:
“In multivariate analyses, whole-fat dairy consumption was most strongly associated with higher trans-palmitoleate levels. Higher trans-palmitoleate levels were associated with slightly lower adiposity and, independently, with higher high-density lipoprotein cholesterol levels, lower triglyceride levels, a lower total cholesterol–HDL cholesterol ratio, lower C-reactive protein levels, and lower insulin resistance. Trans-palmitoleate was also associated with a substantially lower incidence of diabetes…Protective associations with metabolic risk factors were confirmed in the validation cohort.”
Of course, this study does address the widespread problem of dairy allergy, nor does it discriminate between the widely varying qualities of dairy (organic from grass-fed free-range animals versus industrial dairy). But it does caution against the wholesale discrimination against fats in general and the dairy food group in particular. As always, clinical and lifestyle decisions depend on the needs of the individual which can be verified by objective outcome markers. Practitioners and health conscious individuals can consider the authors’ conclusion:
“Circulating trans-palmitoleate is associated with lower insulin resistance, presence of atherogenic dyslipidemia, and incident diabetes. Our findings may explain previously observed metabolic benefits of dairy consumption and support the need for detailed further experimental and clinical investigation.”
Studies examining the epidemiological effect of a food rarely disclose its quality and source. Do you ever wonder if a study on meat, for example, might give different results if the subjects consumed only organic grass-fed meat rather than meat from hormone and antibiotic-laced feedlot animals fed on grain silage and offal? A 
Perhaps it has something to with what the cows were eating. A 
Too bad the authors of the Australian study weren’t able to specify what those Australian cows ate. But another fascinating 
Most of you reading this are aware that a lower glycemic diet can promote weight and fat loss through its beneficial effect on insulin levels. But which is better for