A founding father of the plant-based movement, Dr. T. Colin Campbell, shares what he thinks of Beyond Meat, the latest study on meat-eating, the keto diet, and why the heck it took so long for us to get the memo that plants are good for us and animal protein isn't. Read this before you pick up a fork again.

People who want to eat healthfully and do so by choosing a whole-foods, plant-based diet have been influenced over the years by many leading authorities, from Frances Moore Lappe (author of “Diet for a Small Planet,” 1971) to Michael Pollan (“Omnivore’s Dilemma,” 2006). But the man who has been studying food and health longer than most of us have been alive is T. Colin Campbell, the 85-year-old emeritus Cornell professor who is featured in the documentary “Forks Over Knives,” and who, with his son, Thomas M. Campbell II, wrote the bestselling book on nutrition, “The China Study” (2004). His new book, "Whole: Rethinking Nutrition," is a summation of a life's research into the benefits of a whole-food, plant-based diet for our own health and that of the planet and future generations to come. 

Although Dr. Campbell grew up on a dairy farm, milking cows and eating meat, his lab work as a biochemist convinced him that all animal products are likely harmful to our health and should be avoided. 

Forks Over Knives

Campbell could be called the godfather of the whole-food, plant-based diet movement. His books and his teachings, both at Cornell and around the world (his TED Talk will blow your mind), plus his prominence in Forks Over Knives, has launched more new vegans than most other authors or doctors combined.

More people are trying to add more plants to their plate than ever. That said, there is still a long way to go. Only 10 percent of Americans identify as vegetarian and 3 percent as vegans. Still, in a recent study, 21 percent said they “want to ditch meat” from their diet and are considering going plant-based. Overall 80 percent of Americans intend to replace some or all meat according to Numerator's InfoScout OmniPanel. 

Here is Campbell’s take on the latest plant-based burgers, where the plant-based diet movement is today and where it’s going. 

Note: This interview was edited and condensed for clarity and readability.

Q: In your highly influential “China Study” many years ago, you looked at 65 counties in China in the early 1970s, before eating habits there had been affected by the West. You found a convincing connection between eating a plant-based diet and being free of Western diseases like heart disease and cancer. Why did you embark on that study? 

CC:  I did that study primarily to ascertain whether the decades-long research findings in the laboratory coincided with a human population. In the laboratory, the big thing that really caught my attention was that cancer was related to nutrition. The book called “The China Study” is a review of these findings I had collected over the years, taking into consideration both the experimental work and human populations.

I came from the farm and milking cows. What I learned was that the high animal-protein diet, which had been so revered for decades, was associated with an increased risk for cancer—exactly the opposite of what I thought. I was seeing some pretty provocative things. In the laboratory, we could turn cancer on and off by just changing our nutrient consumption.  

 Q: It’s a very confusing time to try to be an educated eater. There are a lot of studies suggesting that grass-fed meat is good for us and that grains can cause disease. What do you think of that? Is there an argument against eating grains? And what about freely consuming olive oil and coconut oil? Where I live, that is quite popular. 

CC: Too many people creating the confusion are not in it for the right reason. We love hearing good things about our bad habits. Like olive oil. There was a big corporate push to get olive oil into Western society. They relied on research on the Mediterranean diet and argued that its success was due to the high amount of olive oil they used. That was an overstatement and an oversimplification.

My wife and I do not use added oil. And, except for a few individuals with diagnosed problems, there is no reason to avoid grains. It’s not valid research. Eating whole foods means to eat vegetables, whole grains, nuts, seeds, and fruit. Eat them as they are produced in nature. I am doing a new book on exactly that topic -- on why there is now so much confusion. There is a reason for that. I go back in history to the late 1700s.

Q: For someone who is trying to eat plant-based and gets close—is close good enough? 

CC: Many people see some advantage to getting within 75 percent of the desired goal, but they won’t see the ultimate benefit. Doing the diet the right way actually treats or reverses disease. That’s the most exciting story of all. Heart disease begins to clear up in a week or two. Diabetes as well. It is a remarkable effect if you get rid of all animal products. No animal food. The diet should be whole plant-based foods, being careful not to add in oil or sugar. If you give a group of people this food for ten or fifteen days, almost every single person sees a benefit. 

Q: Is there a timeline for results? 

CC: About 50 years ago, we were showing in experimental animal studies in my laboratory physiological and biological responses within hours, certainly within days, upon nutritional intervention, as in the development of experimental cancer (in the lab). This implied that chronic disease, if nutritional in origin (e.g., heart disease, cancer, and diabetes), could be treated surprisingly quickly upon changing nutrient consumption.

This concept has been independently supported in clinical trials on heart disease patients by clinicians Caldwell Esselstyn, MD, and Dean Ornish, MD, in the 1990s, and still earlier in the 1950s, by Lester Morrison, MD. Results of an 8-week very formal study was recently published by my son Tom and his wife Erin (Nutrients 11 (2019). 

BenBella Books

Q: Is it too late to start later in life? Is it like smoking? In a few weeks do the benefits take hold?

CC: Yes, they will—it seems to work. It’s really remarkable. I get asked that quite a bit. We also can see changes in the lab rather quickly.  A blood cholesterol drop of 50 to 100 points can be seen in 10 days. 

Q. What do you think of meat substitutes like Beyond Meat and the Impossible Burger

CC: It’s a step in the right direction because it’s making people conscious of some of the problems we face. On the other hand, there are some difficulties. A lot of these rely on soy and 90 percent of the soy is GMO. And that is worrisome. But I do think it’s a step in the right direction. I only hope that this will interest people in going the whole way.

Q: Studies seem to suggest that eating fish is good for you and that those who consume fish are as healthy as those who eat no animal products. So, what do you think about fish?

CC: The most commonly cited health benefits seem to be that fish is a good source of protein, vitamin D and Omega-3 fat. I don’t buy that—we don’t need animal-based protein, vitamin D is best obtained from sunlight, and Omega-3 fats, when taken as supplements, do not have the benefits cited. Also, the ratio of pro-inflammatory to anti-inflammatory fats matters most and many sources of fish are also major sources of environmental chemicals and bacterial contamination. Bottom line is that fish do not contain fiber and antioxidants like plants do. So, on balance, I don’t eat fish.

Q. And what about intermittent fasting? 

CC: I had an experience many years ago when I was at MIT, when I isolated an extremely toxic chemical later identified as dioxin and got a heavy dose. That created some problems for me over the next 25 years, since it was 800 times the maximum safely allowed. There were some neurological problems that I experienced. I was slurring my words. In the late ‘80s, I had to quit lecturing. I tried all kinds of treatments. As a last resort, I went to a fasting clinic for 12 days. I went back a year later, and the second time I did it for 10 days. My symptoms started to clear up. We know that fasting will allow the body to clear itself of toxins. If someone has a bad condition of some sort, one of the things they might want to try is fasting—medically supervised, that’s very important. And then go off the fast and onto a plant-based diet. 

Q: Critics of your work say you mistake correlation for causation. How do you answer that? 

CC: My critics are right when we attempt to assign causality to specific food factors in correlation studies. But these critics fail to understand the science of nutrition, which involves countless nutrients and related factors working together as a collective cause. 

When we believe that nutrition is the effect of individual nutrients within food acting independently, obviously this means that correlation of individual nutrients does not infer causation. But if we understand nutrition to be a collective nutrient effect, then we can use correlations of indicators of that collective effect with disease and indeed causation. 

Criticizing correlation as not inferring causation in nutrition science is one of the greatest failures in nutritional science for well more than a century—thus failing to recognize a remarkable, nutritional effect on health and disease. 

This failure results from treating nutrition as a pharmaceutical-like effect (nutrient-by-nutrient) when it is not. It’s a central tenet of my next book, where I describe extensively published evidence to support this point of view.

Q. How do you think we can solve the problem of poor eating habits?

CC: I think it is well past time to train physicians in nutrition. The medical profession is created around the idea that there are specific causes of specific diseases which are treated with specific medicines. It’s a very reductionist idea that fails to demonstrate the remarkable effects of nutrition. 

I am traveling all over the country and abroad and lecturing to medical schools and medical conferences. I am encouraged because in more recent times, I am received by physicians and other medical professionals with increasing enthusiasm, with audiences of hundreds of people, a few times more than a thousand. 

Doctors are highly intelligent, diligent people who want to serve their patients. But when they receive no nutrition training, it’s very difficult for them to use this strategy in treating patients. Their practices are largely controlled within an environment referred to as ‘standards of care’. 

In turn, these practitioners are reimbursed by for services under the guidance of approximately 130 medical specialties, not one of them called nutrition. This system, controlled by very powerful forces and institutions, needs to fundamentally change.

Q. When did you start eating a plant-based diet? 

CC: I started around 1980 when I was about 45 years old. If you stay with it for a month or so, your taste buds begin to change. They begin to discern a new pleasurable experience. The body is adjusting. Once that point is reached, we discover a delicious and healthful experience that is highly likely to last a lifetime.

Q: What do you eat in a typical day? 

CC: In the morning we tend to eat oatmeal or dry cereal. And fruit. The combination of cereals and fruits—that is a staple in our family.  I don’t eat ham and eggs and drink large amounts of milk like I did when I was a kid. We might have some potatoes. My wife cooks them in a non-stick pan in water or vegetable broth, not oil. Baking them in an oven is even better. For dinner, my wife makes a variety of dishes. We usually have a grain of some sort like brown rice or whole grain pasta. We eat a lot of legumes and beans and different kinds of spices and herbs. We eat nuts.

Q: How would you try to get people on this path? 

CC: I don’t like to be a proselytizer. That’s not my point. I just try to explain the information well enough so they say they will try it. It may take a while. 

Author's note: After this interview was published on The Beet, a controversial review study came out that claimed there is no significant evidence linking a reduction in meat consumption with a reduced risk of disease. Campbell released his own position paper titled: Hullabaloo! A State of Confused Noise Surrounding Meat Consumption, refuting the science of the study. For the entire statement please see this. He opens his rebuttal with the statement: "There’s a big story making all the lead news outlets today that is the very definition of ‘fake news’." Here is his conclusion:

"This report displays a severe and fatal lack of understanding of the concept of nutrition. It refers to evidence as if nutrition were a derivative of pharmacology; this is a figment of the modern medical establishment’s imagination. Rather than a derivative of pharmacology, nutrition is a science discipline of the highest priority, and our failure to understand this discipline has resulted in an unimaginable number of lives prematurely lost and dollars wasted.

"These authors have failed, miserably, in their understanding of this topic and are doing a great disservice to the public."

Trish Hall, the author of just-published Writing to Persuade, wrote and edited for The New York Times and The Wall Street Journal.