Trans-palmitoleic acid consumption linked to reduced Type 2 diabetes risk
MedWire News: Consumption of trans-palmitoleate, a component of dairy products not produced by the body, reduces insulin resistance and incidence of diabetes, report US researchers.
"There has been no clear biologic explanation for the lower risk of diabetes seen with higher dairy consumption in prior studies," said lead author Dariush Mozaffarian (Harvard School of Public Health, Boston, Massachusetts).
"We wonder whether this naturally occurring trans fatty acid in dairy fats may partly mimic the normal biologic role of its cis counterpart, cis-palmitoleic acid, a fatty acid that is produced in the body. In animal experiments, cis-palmitoleic acid protects against diabetes."
Mozaffarian and team carried out a prospective cohort study between 1992 and 2006 including 3736 adults from the Cardiovascular Health Study from four US communities. They investigated whether circulating levels of trans-palmitoleate at baseline influence metabolic risk and incident Type 2 diabetes.
Individuals who consumed whole-fat dairy were most likely to have high circulating levels of trans-palmitoleate.
Comparing the highest with the lowest quintile for trans-palmitoleate, the researchers found that high-density lipoprotein (HDL) levels were 1.9% higher, and triglycerides, total cholesterol-to-HDL cholesterol ratio, C-reactive protein levels, and insulin resistance were 19.0%, 4.7%, 13.8%, and 16.7% lower, respectively.
Overall, 304 individuals developed incident Type 2 diabetes during the study. Those in quintiles four and five, had a 59% and 62% reduction in risk for incident diabetes compared with quintile one, respectively.
"Our findings support a role of this fatty acid in previously observed metabolic benefits of dairy consumption, with pathways potentially related to insulin resistance, atherogenic dyslipidemia, and regulation of hepatic fat synthesis," write the authors in the Annals of Internal Medicine.
"These results support the need for additional detailed experimental and clinical investigation, including animal experiments and metabolic feeding studies, to assess the potential health effects of trans palmitoleate."
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By Helen Albert