No significant link between whole-fat dairy and heart disease or stroke
A new study supports the growing body of evidence showing that consumption of full-fat milk, yoghurt, cheese and butter does not increase heart disease, stroke or overall mortality in older adults. The study also suggested that increased levels of one fatty acid may actually lower the risk of stroke.
The study evaluated how multiple biomarkers of fatty acid present in dairy fat related to heart disease and all-cause mortality over a 22-year period. This method, as opposed to the more commonly used self-reported consumption of diary foods, gave greater and more objective insight into the impact of long-term exposure to these fatty acids.
Nearly 3000 adults age 65 years and older were included in the study, which measured plasma levels of three different fatty acids (circulating pentadecanoic, heptadecanoic and trans-palmitoleic acids) found in dairy products at the beginning in 1992 and again at six and 13 years later. Concentrations of these fatty acids in the blood correlate with self-reported dairy consumption and are significantly increased in response to dairy or whole-fat dairy consumption in controlled trials.
None of the fatty acid types were significantly associated with total mortality. In fact, circulating heptadecanoic acid was linked was associated with lower CVD mortality (extreme-quintile HR: 0.77; 95% CI: 0.61, 0.98), with a 42% lower risk of stroke mortality (HR: 0.58; 95% CI: 0.35, 0.97).
This study shows that long-term exposure to circulating phospholipid pentadecanoic, heptadecanoic, or trans-palmitoleic acids is not significantly associated with total mortality or incident CVD among older adults. It provides further evidence that dairy fat does not increase the risk of heart disease or stroke. Low-fat dairy foods often include high amounts of added sugars, which may lead to poor cardiovascular and metabolic health.
De Oliveira Otto M, et al. Serial measures of circulating biomarkers of dairy fat and total and cause-specific mortality in older adults: the Cardiovascular Health Study. Am J Clin Nutr 2018; https://doi.org/10.1093/ajcn/nqy117