One of the things we ask our executives prior to attending our LAP program is to describe the healthy and unhealthy aspects of their diet. I always find this interesting as it gives insight into prevailing nutritional beliefs. Generally under the healthy they will list vegetables. Sometimes they include fruit. This is good to hear, the message is out. Yes vegetables are good for us, as is fruit. But when I look at how many servings of fruits and vegetables they report that they eat (another question we ask), on average they only eat 3-4 servings a day!  (Women tend to do slightly better than the men, but not by much). Our data show that 70% don’t eat the minimal recommendation of 5 or more and only 3% eat the ideal of 9 or more. Kudos to that 3%. 

But another disturbing trend is that many will say they limit carbs and they try to eat more lean protein (I don’t know exactly what that means, but I suspect they are not referring to beans). I see this stated over and over again. This is a bit unfortunate as I think it reflects what our nutritional discourse has become. We now refer to foods according to a macronutrient label. And generally speaking, carbs are bad and protein is good. 

David Katz of Yale University likes to say, “we seem to have an insatiable appetite for mere grains of truth about diet and health then the complete recipe.” He goes on to say, that in order to advance our nutritional dialogue we need to get past this pre-historic, reductionist approach and stop referring to foods is if they exist as isolated nutrients.

Thus chicken is now protein, grains are carbs, dairy is calcium, wheat is gluten and fish are omega-3s. 

Reductionism (i.e. thinking of foods in terms of isolated nutrients) in nutrition is not without its usefulness. It helps to inform as to why certain foods might be helping or hurting us. It is useful for determining underlying mechanisms or biological plausibility. It can be useful when trying to identify nutrient deficiencies. 

But we also need to consider the health impact of consuming the actual food! The packaging is important. Lentils and lollipops, both rich in carbs, are not the same foods.

Blueberry consumption, for example, has been shown to improve brain function in older adults. Could it be due to the antioxidants like polyphenols? We suspect so, but don’t really know for sure. More and more, scientists are recognizing that there is a nutrient synergy. There are loads of nutrients in blueberries and it is likely the synergistic effect of them all (including the antioxidants) that is beneficial. Antioxidants eaten in the blueberry package is helpful. Antioxidants eaten as a supplement aren’t (and could in fact be harmful).  

A useful way to study nutrition and health outcomes is to look at eating patterns. Two types of eating patterns scientists have studied are the Western pattern and the Prudent pattern. 

The Western pattern is characterized by high intakes of meat, dairy, refined grains, and fast foods (like french fries), while the Prudent pattern is characterized by high intakes of vegetables, fruits, whole grains, nuts, legumes and can include small amounts of fish, i.e. it is a diet that is comprised primarily of whole plant foods.  

What is striking about these studies is that risk for heart disease, cognitive decline, obesity, diabetes and certain cancers increases as consumption of Western foods goes up. Conversely risk for those same conditions goes down as adherence to a Prudent style diet goes up. This holds true even after adjusting for other lifestyle factors. A recent (2015) longitudinal  study even found that a Western diet is associated with a smaller hippocampus: and a Prudent diet with a larger one. 

Sure, these studies only assess associations and not cause and effect, but the results are worth paying attention to as there is biological plausibility which can explain these associations. The ‘biological plausibility’ link is to an article that is worth reading, BTW.

Part of my point is that there is remarkable consistency when looking across a variety of diseases in relation to these dietary patterns; which taken together would strongly suggest that eating a diet comprised primarily of whole plant foods and limiting intake of both animal and processed plant foods is a good idea.

So what is it about the Prudent pattern that is helpful and what is it about the Western pattern that is harmful? Is it the fat, the protein or the carbs? No, they both have fat, protein and carbs and the balance of these is likely not that different between the two. Rather it is the foods that make up these diets that makes the difference. The types of foods matters.

This reductionist approach has spawned a multi million dollar supplement business. It has gotten a lot of people to go gluten free. It has created lots of rather meaningless debate about fat and carbs and protein. It has helped sell lots of dairy products and demonized healthy whole grains. No single nutrient will save our health, any more than eliminating single nutrients (like gluten or carbs) will save it.