Why nutrition advice should focus less on nutrients (and more on foods)

Nutrition advice worldwide is still often focused on nutrients to discourage. The general advice is to consume less salt, less saturated fat, and less (added) sugars. This based on epidemiological studies on the relation between intake of these nutrient and illnesses or mortality. This may seem to make sense, but the logical fallacy is the underlying assumption that the effect of foods on health is a simple sum of the effects of the nutrients a product is composed of. This does, however, not take into account the interaction nutrients can have and the effect of the food matrix  on the health effect.

One prime example of this effect can be found when looking at full fat dairy products. In many countries, the official advise to consumers is to choose reduced/low fat dairy products, based on epidemiological studies that show that increased saturated fat intake relates to increased incidence of cardiovascular diseases. However, there are two problems with this advice, the saturated fats as such as well as the matrix effect.

First, with regards to the saturated fat as such. Saturated fat is a term used for a broad group of components. Within this group, it is known that different saturated fatty acids have very different effects on human physiology. But the physiological effect of the whole plethora of fatty acids present in dairy fat is much less clear.

But that’s not all, because there is also the matrix effect. There are two elements to this. First, there is a range of nutrients present in full fat dairy products that may interact with each other. For examples, the protein and minerals in dairy may change the physiological response to dairy lipids. Second, dairy products digest different depending on the structure (e.g. milk vs cheese) that may also impact the physiological response.

Studies on foods in relation to diseases and mortality do not show a negative relation between intake of full fat dairy (neither milk nor cheese) and e.g. cardiovascular disease or other diseases and mortality. This shows that nutrition advise should be based on the relation between foods and health and not the relation between nutrients and health.