As a doctor, it is my job to figure out the best way to keep my patients healthy. From my perspective, food is medicine, perhaps the most powerful drug on the planet with the power to cause or cure most disease. If food is more than just calories, if food is information that controls every aspect of our biology and health, then I better know what to advise people to prevent, treat and even reverse chronic disease.
So the fundamental question of our time, given that the cost of chronic disease caused mostly by what we eat will cost our global economy $47 trillion over the next 20 years and cause over 50 million preventable deaths a year is this:
What should I eat to feel good, lose weight and get and stay healthy?
On the one hand, Lebron James is eating Paleo and the No. 1 tennis player in the world cut out gluten and dairy and went from not winning at all to winning everything in just one year. But on the other hand, Rich Roll completed five Iron Man marathons in seven days on a vegan diet.
The Problem with Nutrition Research
Looking at the research it is easy to get confused. Vegan and vegetarian diet studies show they help with weight loss, and lower cholesterol. Paleo diets seem to do the same thing. So should you be shunning animal foods and eating only beans, grains and veggies or should you eat meat and fat without guilt and give up all grains and beans?
Essentially, each camp adheres to their diet with near religious fervor. And each can point to studies validating their point of view. We call this cherry picking. After reading dozens of studies on vegan and paleo diets, even I could get confused. But I don't because I read BETWEEN the lines not just the headlines. I read the methods and analyze the actual data to learn what the studies actually demonstrate.
The problem with nutrition research is that most of it relies on large studies of populations and their dietary patterns obtained mostly through dietary questionnaires or 24-hour dietary recall. The first study linking saturated fats to heart disease by Ancel Keys (and on which 50 years of dietary policy to eat low fat was based) looked at about 30 men from Crete and their previous day's diet and linked that to the fact they had fewer heart attacks than people from countries that ate more saturated fat. Skimpy evidence at best! In fact, most of the "evidence" that fat in general and saturated fat in particular is bad for us is being rigorously challenged by better and more specific research.
These type of studies are further complicated because it is very hard to tease out the factors that matter. For example, when Asians move from Asia to the US, they eat more meat and have more heart disease and cancer, but they also consume far more sugar. So it is the meat or is it the sugar? Hard to know. These types of population studies also cannot prove cause and effect, only show correlation. Yet, the media and consumers take it as gospel. We thought dietary cholesterol was bad and were told to avoid egg yolks at all costs. Turns out they are good for you and have no impact on cholesterol.
Many experimental studies on vegan or paleo diets, which should give more direct evidence of cause and effect often have only small numbers of people in the study, making it hard to draw firm conclusions. For example, one study found both a low-fat vegan diet and a diet based on American Dietetic Association (ADA) guidelines improved glycemic and lipid control for Type 2 diabetes, yet the study used less than 100 participants, hardly making it definitive about vegan diets.
Even worse is that the diets they use for comparison (the control group) are not ideal alternative diets. Comparing a vegan diet of chips and Coke, bagels and pasta to a paleo diet of healthy veggies and grass fed meat won't be very helpful, nor would comparing a paleo diet of feedlot meat, bologna and no fresh veggies to a whole foods, low-glycemic vegan diet.
Also, eating a low-fat vs. a high-fat vegan diet has very different health benefits. The Eco-Atkins or high-fat, high-protein, low-carb, low-glycemic vegan diet performs better for weight loss and cholesterol lowering than a low-fat vegan diet that avoids nuts, seeds and avocados.
RD Laing said that "scientists can't see the way they see, with their way of seeing."
So how do you make sense of the contradictory, oftentimes confusing information, break past the unnecessary polarization of paleo and vegan camps, and find a path that forges an ideal weight and optimal health? Find out why I call myself a Paleo-Vegan. That's what I'll explore in part two of this blog.
Wishing you health and happiness,
Mark Hyman, M.D.
Mark Hyman, M.D., believes that we all deserve a life of vitality -- and that we have the potential to create it for ourselves. That's why he is dedicated to tackling the root causes of chronic disease by harnessing the power of Functional Medicine to transform healthcare. Dr. Hyman and his team work every day to empower people, organizations, and communities to heal their bodies and minds, and improve our social and economic resilience.