For decades, health guidelines have encouraged the consumption of fat-free and low-fat dairy products. Concerns centered around the claim that saturated fats in whole milk, cheese, and yogurt could increase cholesterol levels and harm heart health. However, a recent study challenges these established beliefs.
This study, led by University of Toronto professor Harvey Anderson and published in The Journal of Nutrition, observed that adults consuming full-fat dairy daily for 12 weeks faced no adverse effects on their weight, body fat, or cholesterol. In fact, the study revealed some associated health benefits.
Key Findings
The study participants consumed three servings of full-fat dairy each day. Results showed no significant changes in weight, body fat, cholesterol, or insulin resistance compared to a group on a low-dairy diet. Furthermore, those in the full-fat dairy group experienced improved blood pressure and greater intake of calcium, protein, and vitamin D.
Supported by Dairy Research Cluster 3 under the Canadian Agricultural Partnership AgriScience Program, this research highlights the complexity of the nutrients found in dairy products. Anderson explained to Newsweek that the physical structure of dairy, which includes casein and whey proteins bound with fats and other nutrients, contributes to the steady nutrient delivery and health benefits beyond isolated nutritional components.
Expert Insight
Registered dietitian Jessica Corwin emphasized that these findings add important nuance to longstanding dietary guidance. She stated that for many people raised in the era of fat-free diets, the negative impacts on cravings and satisfaction are well-known. According to Corwin, the study does not prove full-fat dairy is more beneficial than its low-fat counterparts, but it does challenge the assumption that full-fat dairy necessarily leads to weight gain or worsens heart health concerns.
We can’t always predict the health effects of a whole food by isolating one nutrient within it.” – Jessica Corwin
Corwin also reiterated the importance of whole foods, noting that dairy offers a multitude of nutrients such as high-quality protein, calcium, and potassium within a complex food matrix. This underscores the notion that whole foods are often more beneficial than isolated supplements.
Research Design
The study involved 74 overweight or obese adults, divided into three groups. One group followed a low-dairy, calorie-restricted diet, another followed an energy-neutral diet with three dairy servings, and the third had an unrestricted diet also including three daily servings of dairy. All participants were advised based on Canada’s food guide and were provided with full-fat dairy products for the study duration.
Implications for Dietary Guidelines
Traditional dietary guidelines globally, including in Canada, have recommended low-fat dairy due to assumptions that saturated fat raises cholesterol and cardiovascular risks. However, researchers believe the new study supports the ‘dairy matrix hypothesis.’ This hypothesis suggests the nutrient absorption and digestion depend significantly on the food’s physical structure, thus the health effects of food are not contingent on isolated nutrient analysis but on the interaction of its components.