For decades, Americans have been advised that cutting fat was key for a heart-healthy diet, spurring an industry of low-fat dairy products. A new generation of nutrition research is challenging some of those long-held beliefs - suggesting that for dairy products, the overall effects of whole-fat varieties on heart health may be positive.
A new study from the University of Minnesota School of Public Health adds to this shift. Using data from more than 3,100 participants in the Coronary Artery Risk Development in Young Adults (CARDIA) study, researchers tracked dairy consumption and measured coronary artery calcification - a buildup of calcium in the arteries that can be an early sign of heart disease. This is believed to be the first prospective study on the associations of whole-fat, low-fat and total dairy consumption with risk of coronary artery calcification.
Study participants were first surveyed in the mid-1980s, when they were between the ages of 18 and 30, and then tracked over the following 25 years. Using advanced statistical modeling, researchers looked at how different types of dairy predicted the presence of coronary artery calcification later in life. The results, published in The Journal of Nutrition, found:
- Whole-fat dairy appeared protective against coronary artery calcification. Participants who consumed the most whole-fat dairy had a 24% lower risk of developing coronary artery calcification compared with those who consumed the least.
- Low-fat and total dairy showed no clear relationship with risk of coronary artery calcification. Intakes of low-fat and total dairy products were not significantly linked to the presence of this heart disease marker.
- Body weight may play a role. The protective effect of whole-fat dairy weakened slightly after researchers adjusted for participants' body mass index (BMI), suggesting that the slightly lower average BMI of those who consume dairy may partly explain the association.
"People who consumed more whole-fat dairy in young adulthood were less likely to have early heart disease decades later," said Ethan Cannon, a researcher in the School of Public Health and lead author. "While nutritionists have long been concerned about the saturated fat found in whole-fat dairy, our research serves as a reminder that the overall effects of a food are not equivalent to those of the individual nutrients it contains."
Future research should further explore the impacts of whole-fat dairy on heart health by investigating biological mechanisms, such as the role of specific fatty acids or bioactive compounds in dairy fat.
About the School of Public Health
The University of Minnesota School of Public Health improves the health and wellbeing of populations and communities around the world by bringing innovative research, learning, and concrete actions to today's biggest health challenges. We prepare some of the most influential leaders in the field, and partner with health departments, communities, and policymakers to advance health equity for all. Learn more at sph.umn.edu.
