Popular belief has it — and even some governmental authorities on nutrition agree — that we should avoid full-fat dairy products due to their high content of saturated fats. But, a new study boldly challenges these claims.
This is the main takeaway of a recent study led by Dr. Dariush Mozaffarian, from the Friedman School of Nutrition Science and Policy at Tufts University in Boston, MA.
With their findings, Dr. Mozaffarian and team challenge not only popular opinions, but also the stance of governmental organizations such as the United States Department of Agriculture (USDA) and the U.S. Department of Health & Human Services.
The two bodies advise people to avoid full-fat dairy due to its impact on cholesterol levels. The saturated fats found in whole-fat dairy products, warn the USDA, raise levels of low-density lipoprotein (LDL) cholesterol, also known as the "bad" kind of cholesterol.
However, the new study turns the idea that full-fat dairy is bad for you on its head. The surprising findings were published in the American Journal of Clinical Nutrition.
Marcia Otto, who is an assistant professor in the Department of Epidemiology, Human Genetics, and Environmental Sciences at the University of Texas Health Science Center at Houston, is the first and corresponding author of the paper.
Dairy fat may prevent heart disease, stroke
To study the effect of dairy on mortality risk and cardiovascular health, Dr. Mozaffarian and team examined over 2,900 U.S. seniors, aged 65 and above.
The researchers measured the participants' blood plasma levels of three fatty acids contained by dairy products at the beginning of the study in 1992, 6 years later, and then 13 years later.
Associations with "total mortality, cause-specific mortality, and cardiovascular disease (CVD) risk" were examined.
During the 22-year follow-up period, 2,428 of the participants died. Of these deaths, 833 were due to heart disease.
However, none of the three fatty acids examined correlated with the risk of total mortality. In fact, high circulating levels of heptadecanoic fatty acid were associated with a lower risk of death from heart disease.
Also, adults with higher levels of fatty acids overall were 42 percent less likely to die from stroke, revealed the analysis.
Dietary guidelines should be revised
According to the study's corresponding author, the findings suggest that current dietary guidelines need to be amended.
The 2015–2020 Dietary Guidelines for Americans issued by the Office of Disease Prevention and Health Promotion recommend the consumption of "fat-free and low-fat (1 percent) dairy, including milk, yogurt, cheese, or fortified soy beverages (commonly known as 'soymilk')."
However, Otto disagrees. "Consistent with previous findings," she says, "our results highlight the need to revisit current dietary guidance on whole fat dairy foods, which are rich sources of nutrients such as calcium and potassium."
"These are essential for health not only during childhood but throughout life, particularly also in later years when undernourishment and conditions like osteoporosis are more common," adds the researcher.
"[D]airy fat, contrary to popular belief, does not increase [the] risk of heart disease or overall mortality in older adults. In addition [...], the results suggest that one fatty acid present in dairy may lower risk of death from cardiovascular disease, particularly from stroke."
She adds, "Consumers have been exposed to so much different and conflicting information about diet, particularly in relation to fats," and she highlights the fact that "a growing body of evidence" suggests that dairy fat is actually good for you.
"It's [...] important to have robust studies, so people can make more balanced and informed choices based on scientific fact rather than hearsay," Otto concludes.