Why Nutrition Science Is Flawed…

“Eggs are an unhealthy source of cholesterol”.

“Eggs are a rich source of fat-soluble vitamins and actually cholesterol is not all bad”…

“Studies show vegetarian cohorts live longer than meat-eaters”.   

“We need bioavailable protein and animal-based collagen to thrive”.

“The [Keto] [Vegan] [Carnivore] [Paleo] [Mediterranean] [IIFYM] Diet cures all!”.

Confused? You’re not alone. With contradictory recommendations appearing in the headlines every other week, it seems impossible to know how to nourish ourselves properly, even with the best of intentions.

Criminally, the way our food system is set up in North America, food lobbyists spare no effort in influencing public policy and food regulations, including but not limited to:

• advocating for labeling practices that favour their products
• opposing sugar tax proposals
• marketing ultra-processed foods to vulnerable demographics (such as children) through the media
• and even funding studies that are designed to show a pre-determined outcome (and if they don’t show said outcome, the results typically go unpublished)

Essentially, this means that, when it comes to nutritional studies of humans, you can find evidence that supports any theory you want. This is just one of a long list of reasons why nutrition recommendations may appear frustratingly bipolar. Another is that, while traditional scientific method works very well in hard sciences such as physics and chemistry, in softer sciences like nutrition, it’s much more difficult to prove a theory beyond a shadow of a doubt.

Now, stay with me here. As a responsible practitioner, I strongly believe in science-backed and evidence-based information, I promise. But the reality is that nutrition science has its limitations, one of which being that you cannot ethically subject humans in a placebo-controlled trial to a known problem. We can test toxic compounds on animals, but we are different from animals in a myriad of ways, so the results cannot be taken at face value.

An important side note here is that safety testing also rarely takes into account cumulative compounding effects; a study may show that glyphosate (an herbicide that is commonly used on crops like wheat, corn and soybeans) is safe for humans in very small amounts, but is it safe in the amount that the average person typically ingests on the Standard American Diet? Or the amount they consume over time? Or in combination with all the other artificial sweeteners, preservatives, flavour enhancers and additives that also tested “safe in very small amounts”?

So that leaves us with observational studies, in which it’s impossible to isolate variables in a controlled environment. The China Study was a good example of this; Examining the link between the consumption of animal products and chronic illness, the China Study was a 20-year survey that looked at mortality rates from cancer and other chronic diseases in developing countries in China from 1973 to 1984. The conclusion was that people who ate a predominantly whole-food, plant-based diet that was devoid of animal products were able to escape, reduce or reverse the development of disease.

A common criticism of the China Study, however, is that there were other important factors to be taken into account; Alongside the rise of meat consumption in a developing country, for example, you might also see the introduction of more highly-processed convenience foods, and/or a more high-stress, fast-paced lifestyle, both of which could certainly drive up rates of chronic disease.

This serves as a reminder that, when it comes to nutrition research, correlation does not always equal causation. Another example of this is the Healthy User Bias: Someone who chooses to follow a vegetarian diet is likely to also engage in other behaviours that are perceived as “healthy”, such as regular exercise or avoiding alcohol and tobacco; Who’s to say that it’s definitely the vegetarian diet that keeps them free of disease?

There is also the misguided idea that, if something can’t be proven with pure science, it must not be true. While this logic stands on principle, it’s not applicable to a relatively young science like nutrition, because there remain countless factors (regarding the human microbiome, for example, or genetics, or the synergistic effects of certain nutrients) that we simply don’t have the knowledge of or means to measure yet.

We know that beta carotene found in carrots, for instance, is a powerful antioxidant that protects against cellular damage and reduces the risk of chronic diseases like cancer. What we don’t know, is why, when we isolate this same beta carotene in a supplement and deliver it in a higher, more concentrated dose, it can actually increase the risk of certain cancers.

It’s important to remember that research into micronutrients is ongoing, and while the established list is quite comprehensive, scientists suspect that there are many, many more vitamins and minerals that are yet to be discovered.

We also know that micronutrients tend to work synergistically, altering or enhancing one another’s effects as they coexist naturally within a whole-food source. And that’s not even to mention the billions of species of bacteria, yeast, fungi, and other organisms that interact with the nutrients in our bodies to influence our state of health, many in ways that we don’t yet understand.

This is where we’ll often hear a standard industry defense along the lines of: “Current evidence doesn’t support the theory that processed seed oils are harmful”, even though, upon observing how they’re made, common sense would dictate otherwise; The reality is that study simply hasn’t been done yet, or there is no market interest to fund it.

So where does that leave us? Does this mean we dismiss all emerging nutrition research as pseudoscience and give up any hope of a healthier, more vibrant life?  

No.

We cannot forget the value of traditional wisdom and common sense. As food author Michael Pollan famously said: “Don’t eat anything your great-grandmother wouldn’t recognize as food”.

Nutrition guidelines really can be that simple.

It’s also arguable that, when it comes to ancestral diets, the relative health and absence of disease that were often observed may very well have been the result of what people weren’t eating, rather than what they were.

Isolated or pre-industrialized communities frequently followed very different food traditions – from the exclusively animal-based diets of the Inuit to the heavy reliance on grains, plants and legumes in traditional Japanese culture. Many apparently healthy (but different) groups shared at least one thing in common: they were eating what nature provided, and their diets did not include modern, ultra-processed foods.

We also cannot forget about the importance of individuation – the reality that literally every body is different, due to genetic factors, gender, age, stress resilience, and a whole host of other factors. What works for one person may not work for another. And this where listening to our body, and attuning to its rhythms, becomes an invaluable tool in guiding us toward better health.

While nutrition science certainly has its place, and every new advancement inarguably adds value to our growing body of understanding, at the end of the day, nature and the human body together hold more wisdom than the most cutting-edge science.