If you’re not familiar with John McDougall, MD, he is perhaps the most well-known leader in the vegan community. He is the author of 13 best-selling books (including The Starch Solution and The Healthiest Diet on the Planet) and has been preaching a high-starch no-oil vegan diet for 40 years.
This podcast is a MUST-WATCH!
In preparation for my interview with Dr. McDougall, whom I have the greatest respect and admiration for, I knew my scientific references had to be rock solid. Before the interview, I explained to Dr. McDougall that while some of my listeners are vegan, he would be speaking to a diverse group of health-conscious eaters. I told him that many people are very confused about what to eat. Each camp, whether Keto, Paleo, pescatarian, forms of vegetarian or vegan, or others, all cite good science to make their case.
I told Dr. McDougall that I would present some confusing non-vegan studies in hopes he would be able to convince us all that we should be eating vegan. After all, a vegan diet is the only diet that has been shown to repeatedly reverse heart disease! He enthusiastically agreed.
Less Meat or No Meat?
Here is a brief overview of some of the confusing studies I was hoping Dr. McDougall would shed light on. In January 2019, the prestigious journal The Lancet published a report on the urgency for the world to consume less meat.
A group of 30 scientists deliberated for over three years and wrote a report suggesting that a continued high-volume meat-eating diet will have dire consequences for the planet.
When I cited this study, Dr. McDougall suggested that it was recommending the “McDougall Diet,” a 100% vegan, no-oil diet. I asked Dr McDougall if I could read from a report so as not be ambiguous: the study as reported by National Geographic states: “It recommends a largely plant-based diet, with small, occasional allowances for meat, dairy, and sugar.”2
I asked: How do you make sense of the “small allowances”? Dr. McDougall’s response was that he knew the head researcher and since he eats meat, we cannot believe this study. Confusing!
The Mediterranean Diet
Shocked by his response, I asked Dr. McDougall about the decades of compelling research on the Mediterranean Diet, which includes whole grains and small amounts of meat and fish. I cited a famous study, published in The New England Journal of Medicine,where more than 7,000 volunteers on a Mediterranean Diet were split into three groups: one given free unlimited almonds, one given free unlimited olive oil, and the third given a low-fat diet similar to the McDougall Diet. The groups that consumed more fat from olive oil and nuts had significantly lower risk of cardiovascular disease.3
This landmark 2013 study was revised in 2018 and concluded the following: “In this study involving persons at high cardiovascular risk, the incidence of major cardiovascular events was lower among those assigned to a Mediterranean diet supplemented with extra-virgin olive oil or nuts than among those assigned to a reduced-fat diet.”3
Dr. McDougall’s response was that you cannot trust the science on the Mediterranean Diet! Even though there are volumes of studies on the health benefits of the Mediterranean Diet, Dr. McDougall did not want to talk about it. Frustrating!
Here is one of the many studies suggesting the benefits of a Mediterranean Diet. In this study (published in the European Journal of Clinical Medicine), more than 2,000 adults aged 20-70 on a Mediterranean Diet were evaluated for type 2 diabetes risk. Those who followed a Mediterranean Diet had a significant reduction in risk of developing type 2 diabetes. Those who ate more fish, nuts, seeds, legumes, and monounsaturated fats (as found in olive oil) had an even greater reduction of type 2 diabetes risk.1
The point I was trying to make with Dr. McDougall was that there is solid scientific and ethical evidence that we should be eating much less animal protein than is currently consumed and his work over the last 40 years has undoubtedly moved the needle in the right direction. But, there is also good science suggesting benefits from occasionally eating animal protein.
Animal Protein + Longevity
According to the best longevity studies done by Dr. Valter Longo, arguably the world’s most respected longevity researcher, a 90% plant-based diet with 10% animal protein is ideal for health and longevity.4
This 90-10 plants-to-animal-protein ratio is also the diet eaten by the world’s centenarian populations, as discovered by Dan Buettner in his Blue Zone research.
Watch my podcast with Dan Buettner on Blue Zones here.
Most traditional cultures ate a very small amount of animal protein because it was costly. The rich, wealthy, and unhealthy were those who had resources to consume meat in excess. To be fair, the cause of the “wealthy and unhealthy” stigma was more likely eating to excess in general (not specifically meat).
If we look to our more ancient ancestors, hunter-gatherers consumed larger amounts of animal protein at certain times of year, offset with periods of high-starch consumption and fasting in the spring when food was scarce.
Vegan + Vegetarian Deficiencies
Dr. McDougall did agree that veganism and vegetarianism are relatively recent dietary shifts, as there were no hunter-gatherer vegetarians. When I asked him about the science that vegans have a high percentage of B12 deficiencies and to be a healthy vegan, most experts suggest B12, omega-3, multivitamin, and multimineral supplements, he denied need for supplementation.
When I asked Dr. McDougall if he has ever seen a vegan not thriving, he said, “Never!” I was an lacto-ovo vegetarian for most of my adult life, a high percentage of my patients for the past 35 years have been vegetarians, and I have seen a high number of vegetarian-based nutritional deficiencies.
In fact, it is quite common, which is why I wrote The Protein Solution free eBook. Now, could these deficiencies be caused by poor vegetarian eating practices? Yes. I have always said that if you plan to be a healthy vegetarian, you need to set aside two hours per day for cooking—and few have that time to spend. To hear stories about vegans and vegetarians who were not thriving, just Google it.
The reality is that there are volumes of studies suggesting that vegans should be aware of potential deficiencies of B12, omega-3 fatty acids, iron, iodine, vitamin D, calcium, and zinc.5,7,8 Dr. McDougall also published a study based on 5,000 vegans who were not found to be nutritionally deficient.6 Still confusing!
Do Vegetarians Live Longer than Meat Eaters?
It should be noted that “the scientific literature shows that the reduction or exclusion of animal foods may reduce the risk of Coronary Heart Disease and type 2 Diabetes through modifiable factors such as body mass, serum glucose, blood pressure, and serum lipid profile. These disorders contribute to a high mortality rate in Western countries. Nevertheless, the risk of possible nutritional deficiencies in a non-balanced vegetarian diet, due to the absence of nutrients that can nullify these health benefits should not be underestimated.”8
Surprisingly, there have been many such studies measuring all-cause mortality between vegans, vegetarians, pescatarians, and meat eaters. Here are some results:
In a large Seventh Day Adventist vegetarian study with of over 73,000 participants, all-cause mortality was measured. Pescatarians lived longest, followed by vegans, then lacto-ovo vegetarians, and finally, non-vegetarians.9
“In five prospective study analyses of 24,000 vegetarians among a total of 76,000 men and women, mortality from ischemic heart disease was lower in lacto-ovo vegetarians than in vegans.”8
However, “In the European Prospective Investigation into Cancer and Nutrition-Oxford (EPIC-Oxford) cohort study, all-cause mortality among vegetarians in comparison with non-vegetarians was not significantly different.”8
These are somewhat confusing results, but the consensus is that a mostly plant-based diet may deliver greatest longevity. While I tried to get an explanation from Dr. McDougall about whether a small amount of animal protein was needed (to provide omega-3 fatty acids, B12, and other nutrients sometimes lacking in a vegan, no-oil diet), he was unwilling to budge, which I understand, but even most vegan experts agree that to be a healthy vegan, some nutritional supplementation is needed.
There is no better reason to be vegan than to protest factory farming and protect animals. And it can be done in a healthy way. If I had not see so many vegetarians in my practice for the last 35 years not thriving, I would be recommending a vegan diet hands down. The science and most vegan experts (except Dr. McDougall) seem to agree that to be a healthy vegan, some supplements are required. If you feel uncomfortable taking supplements, then the research suggests that a small amount of animal protein (10% of the diet) is needed.
I understand Dr. McDougall’s position, but I don’t feel that saying all science on Keto, Paleo, and other non-vegan diets is flawed or, as he put it, “fake news” is palatable for most of my readers.
This podcast with Dr. McDougall, in my opinion, is a must-watch if you are vegan, vegetarian, or considering becoming so. I hope you enjoy hearing the different dietary perspectives I am bringing onto my podcasts. I feel the more we learn, the better equipped we are to make the best personal dietary choices.
After all, at the end of the day, we may find out (as some of the emerging genetic research suggests), that the best diet may be a completely individual choice based on our genetic digestive abilities. Stay tuned for more on this subject as I continue to interview more of the world’s dietary experts in search of truth!