Our health is made up of a combination of biological, behavioral and environmental factors. While each component independently plays a crucial role, our health is ultimately defined by their interactions and how those uniquely manifest.
This concept is also proving true for the foods we eat and the nutrition they provide. Increasing data suggest that health benefits from foods result not just from the amount of a particular nutrient we eat, but rather the mix of nutrients and how they interact within a more complex structure, like a whole food or even an entire eating pattern. For example, calcium in foods is more bioavailable when vitamin D is present (thank you vitamin-D fortified milk!), but foods high in calcium can inhibit the absorption of iron.
Introducing the Food Matrix
To understand the complexities of isolated nutrients when they’re consumed individually versus in combination with other components as part of a whole food, researchers are looking at the concept of the food matrix. A food matrix, as defined by USDA, is "the nutrient and non-nutrient components of foods and their molecular relationships, i.e., chemical bonds, to each other." The nutritional components are the vitamins, minerals and other health-influencing constituents in foods, such as antioxidants, while the non-nutrient components are the physical structures of the food, such as its form (solid, semi-solid, gel or liquid) and chemical bonds.
Ultimately, the mix of nutrients with the physical structure together can impact nutrient digestion, absorption and metabolism, affecting the overall nutritional and health properties of the food.
The Dairy Food Matrix
Dairy offers a unique look at the role of food matrices because milk is a complex food that we enjoy in various forms: cheese (solid), yogurt (gel) or in a glass (liquid). Transforming milk into these various products requires processing – such as fermentation, heating and other ripening processes – each of which also transforms the original food matrix. Moreover, milk consists of nine essential nutrients, all nine essential amino acids, numerous other vitamins and minerals as well as over 400 types of fatty acids.
Discrepancies With Nutrients in Milk and Dairy Products
A large body of evidence supports dairy’s role in a healthy diet, yet the saturated fat content of dairy foods is constantly under scrutiny. For years, dietary recommendations have encouraged limits on fat (specifically saturated fat) because of associations between dietary intake and chronic diseases. Interestingly, however, a growing body of research suggests that dairy products – and especially full-fat dairy products – are associated with neutral or even reduced risk of developing the same chronic conditions:
- Whole Milk and Type 2 Diabetes:
- This randomized control trial divided 17 healthy adults into two groups, consuming 2 cups of either whole milk or fat-free milk each day for three weeks. The study found that whole milk consumption, in comparison to skim milk consumption, did not negatively impact markers of cardiovascular disease or Type 2 diabetes risk.
- Whole Milk and Obesity:
- In a cohort study of more than 18,000 women who were followed for 17 years, higher consumption of whole-fat dairy products was associated with less weight gain.
- Cheese and Cardiovascular Disease
- This meta-analysis of 15 prospective cohorts concluded that cheese consumption was associated with lower risk for cardiovascular disease, coronary heart disease and stroke, with the greatest reductions in risk for cardiovascular disease observed with consumption of approximately 1.3 ounces of cheese per day.
- Yogurt and Inflammation:
- This randomized control trial involving 120 subjects showed that eating just 1.5 servings of low-fat yogurt per day resulted in greater reductions in biomarkers of chronic inflammation in comparison to eating an unfermented, soy pudding similar in macronutrient and micronutrient composition to the dairy yogurt.
This sample of studies demonstrates the complexities of food and nutrition science, and specifically that while saturated fat may be independently associated with chronic illnesses – such as heart disease, inflammation, diabetes and obesity – when it is part of a diverse array of dairy foods, the health properties shift and even show neutral or positive associations.
As health care providers and nutrition educators, we can leverage this information to help patients and clients reach their health goals by focusing on integrating a variety of whole foods, including dairy, into healthy eating patterns.
For more of the latest dairy nutrition science, peruse our blog.
