Higher consumption of whole-fat dairy linked to lower rates of heart disease
Consuming three or more servings of whole-fat dairy per day—especially in developing countries—has been linked to lower rates of cardiovascular disease, according to research published Sept. 11 in the Lancet. The findings stand in contrast to current dietary guidelines in the U.S., which recommend up to four servings of low-fat dairy a day.
The Prospective Urban Rural Epidemiology (PURE) study, which spanned five continents, 21 countries and 136,384 unique patients, aimed to assess the impact of dairy consumption on cardiovascular risk in a diverse cohort. Though the researchers’ findings echoed those of some other trials, they didn’t quite fall in line with current standards for dairy intake.
“Dairy products are a major source of saturated fats, which have been presumed to adversely affect blood lipids and increase cardiovascular disease and mortality,” first author Mahshid Dehghan, PhD, of the Population Health Research Institute in Canada, and co-authors wrote in the journal. “Using this framework, dietary guidelines recommend minimizing consumption of whole-fat dairy products for cardiovascular disease prevention in populations.”
But those recommendations don’t recognize some of the positive, preventive qualities of higher-fat milks and cheeses, the authors said, like their calcium, vitamin K, natural trans fats and certain phospholipids.
According to the study, PURE evaluated dairy intake among 35- to 70-year-olds using country-specific food questionnaires. Dietary information was recorded at the study’s baseline and participants were followed up for an average of nine years, during which 6,796 deaths and 5,855 major cardiovascular events took place.
Dairy consumption was highest in North America and Europe, Dehghan et al. said, where people consumed on average four servings, or 368 grams, of dairy per day. For the purposes of the study, a standard serving of dairy was considered a cup of milk or yoghurt, one slice of cheese or a teaspoon of butter.
Those in south and southeast Asia, China and and Africa were least likely to consume dairy at an average of 37 grams a day, or less than one serving.
Compared to people who didn’t eat or drink any dairy, consumers who stuck to three or so portions a day saw lower rates of cardiovascular mortality, total mortality, major cardiovascular disease and stroke. Individuals who consumed just whole-fat dairy experienced lower levels of total mortality and major CVD compared to those who consumed less than half a serving of whole-fat dairy a day.
Positive associations were mostly linked to milk and yoghurt, but not cheese and butter, Dehghan and colleagues wrote. There was no connection between dairy intake and incidence of myocardial infarction.
In a related commentary, Jimmy Chun Yu Louie and Anna M. Rangan, of the University of Hong Kong and University of Sydney, respectively, said Dehghan et al.’s findings challenge present dietary standards, but it’s important to recognize certain limitations in the work.
“The results from the PURE study seem to suggest that dairy intake, especially whole-fat dairy, might be beneficial for preventing deaths and major cardiovascular diseases,” Louie and Rangan wrote. “However, as the authors themselves concluded, the results only suggest the ‘consumption of dairy products should not be discouraged and perhaps even be encouraged in low-income and middle-income countries.”
They said the PURE study also only considered intake data from the study’s baseline, and failed to update that information as participants’ diets presumably shifted and evolved. Because of that, they said further work needs to validate the findings before any national guidelines can change.
“[This] is not the ultimate seal of approval for recommending whole-fat dairy over its low-fat or skimmed counterparts,” Louie and Rangan said. “Readers should be cautious and should treat this study only as yet another piece of evidence—albeit a large one—in the literature.”
After graduating from Indiana University-Bloomington with a bachelor’s in journalism, Anicka joined TriMed’s Chicago team in 2017 covering cardiology. Close to her heart is long-form journalism, Pilot G-2 pens, dark chocolate and her dog Harper Lee.