Unlocking the dairy matrix: More than the sum of its nutrients

In the last 50 years, nutrition research has shifted from investigating specific nutrients to recognizing that the impacts of food on health extend far beyond the sum of its individual nutrients. Seeing as nutrients are not consumed in isolation but rather as part of a complex food, recognizing the elaborate network within the food matrix becomes imperative. 

What is a food matrix?

The food matrix is generally described as how nutrients are structured and combined, and how they interact in a food, which ultimately influences nutrient digestibility, absorption, and bioavailability. Growing research suggests that a food’s matrix can significantly influence physiological responses and lead to differential impacts on health and nutrition. 

Defining the dairy matrix and its benefits

Recognized for their nutrient density, milk and dairy products are included in most food-based dietary guidelines worldwide. The importance of the food matrix is well demonstrated in dairy products, as their associated health effects extend beyond the sum of their individual nutrients. However, despite its importance, there is no globally established definition for the dairy matrix. To this effect, a review article surveyed existing literature to put forward a clear, harmonized definition to promote explicitness and consistency in scientific communication. A collective consensus from leading experts in the field of dairy nutrition led to the following definition: “the unique structure of dairy food, its components (e.g., nutrients and non-nutrients), and how they interact”.

Considering the dairy matrix is critical, as it may help explain the discrepancy noticed between theoretical and observed health outcomes related to dairy intake. For example, studies have revealed neutral to favourable effects of dairy consumption on cardiometabolic health outcomes, despite the naturally occurring saturated fat content. The dairy matrix may also support other documented health benefits, such as improved bone health, as well as decreased risk of colorectal cancer. 

These effects can be partly attributed to the interplay of components and structure within a dairy food’s unique matrix, which can influence nutrient digestion and physiological responses. This matrix may vary depending on a combination of many factors, including the type of milk used and the production methods, and may account for the diversity in the health benefits of different dairy foods. For example, the fermentation process of yogurt may amplify health benefits, as its consumption was associated with decreased risk of cardiovascular events, total mortality, and incidence of type 2 diabetes. Additionally, the bioactive short-chain fatty acids and peptides produced by bacteria during the fermentation process of yogurt and cheese provide added protective effects on insulin sensitivity and decreasing blood pressure. 

The importance of the food matrix in public health

In light of these advancements in nutrition research and new insights on the complexity of the food matrix, policymakers and practitioners are now presented with a unique opportunity to translate these findings into effective public health strategies.  Current public health approaches often focus on nutrient profiles in isolation, which fail to capture the entire scope of the health effects of these foods, meals, and dietary patterns. For example, the health effects of dairy cannot be predicted by their nutrient content alone, particularly when only focusing on saturated fat, sodium, and naturally occurring sugar contents. Thus, it may be relevant to develop adapted thresholds for different foods with unique but important food matrices when designing public health policies. This would more accurately reflect the different nutritional profiles of food and whether the targeted nutrients are naturally occurring.

Without accessible and comprehensive information on the broader impacts of the food matrix, it may impede consumers’ abilities to make an informed decision, potentially leading to unintended consequences such as decreased intake of nutrient-rich foods. For example, a study found that substituting 5% of dairy fat with poly- and monounsaturated fats from non-dairy foods led to reduced intake of key nutrients like calcium, vitamins D, A, B12, riboflavin, and niacin, ultimately compromising overall diet quality.

The emerging evidence revealing the dangers of oversimplifying food health effects down to mere nutrient profiles underscores the need for new food-based nutrition guidelines to be tailored based on the food matrix.