The Future of Nutrition Book Cover

The Link Between Nutrition and Disease and the Case for a Whole Food, Plant-Based Diet

Imagine that, in the United States, there were an excess of one million deaths every year that could be prevented, relatively easily, with only a few lifestyle adjustments. You would imagine this to be a top public health priority, and that our health care professionals would be trained to offer the requisite counseling and advice. This would be reasonable for you to think, but you would be wrong.

In The Future of Nutrition, nutritional biochemist and Cornell University professor T. Colin Campbell describes the link between nutrition and disease and why nutrition has been downplayed as an integral part of disease care for decades. Campbell—in synthesizing 60 years of his own and others’ research—details the personal and institutional biases—along with the food industry’s profound influence over nutrition science—in creating an environment where disease care is focused on surgical and pharmaceutical interventions at the expense of long-term health through proper nutrition. 

As Campbell explains, the leading causes of death in the US (as of 2017) are:

  1. Heart disease (647,000)
  2. Cancer (599,000)
  3. Accidents (170,000)
  4. Chronic lower respiratory disease (160,000)
  5. Stroke (146,000)
  6. Medical errors (250,000–440,000)

What you will notice about this list is the preventable nature of many of these diseases, which result from malnutrition or, more specifically, excess nutrition. The over-consumption of processed foods high in simple sugars and fat (and animal protein) results in obesity, high blood pressure, high cholesterol, diabetes, and other pathophysiology that has been shown to increase one’s risk for heart disease, stroke, and even some forms of cancer.

As Campbell demonstrates, if adjusted for malnutrition, the leading causes of death in the US would look as follows (these are conservative estimates):

  1. Heart disease (65,000)
  2. Cancer (180,000)
  3. Accidents (170,000)
  4. Chronic lower respiratory disease (160,000)
  5. Stroke (73,000)
  6. Medical errors (50,000)

All told, with proper nutrition, more than 1.2 million lives could be saved in the US every year (or more). Heart disease and stroke have an obvious link to nutrition; cancer is less obvious but supported by extensive research (much of it conducted by the author); and medical errors would be reduced as fewer people required surgical and medical care. 

Yet despite the nutritional origin of these excess deaths, our health care professionals are largely untrained in the role of nutrition in the promotion of general health. In the United States, disease prevention and treatment is centered on surgical and pharmaceutical interventions, not on the underlying cause of disease. 

Campbell shows that, in 2017, 55 percent of Americans took prescription drugs, taking four per day on average and spending an average of $1,162 every year. The United States is also one of only two countries in the world to permit direct-to-consumer TV advertising of drugs instead of advertising to qualified physicians. Pharmaceutical interventions, of course, in many cases act only as band aids—you can take medication to lower your blood pressure, but the underlying cause of your high blood pressure is likely to be based on your lifestyle choices (diet and exercise). 

So the US spends more money on health care and medications than almost any other country and yet our life expectancy is decreasing. As Campbell wrote:

“Our declining life expectancy leaves America ranked forty-fourth in the world, an astonishing and disturbing rank considering that we have the highest per capita health care costs in the world, by an eye popping margin.”

How could we have allowed this to happen? As Campbell explains, the profession has neglected the role of nutrition “not as a matter of conspiracy, but due to a combination of more mundane human defects like stubbornness, bias, and conformity.” Campbell discusses at length how, for example, cancer institutes were founded on a local theory of disease by surgeons that preferred and were more familiar with surgery, rather than on a constitutional theory of disease that recognized nutrition’s larger role in the prevention and treatment of cancer. This, along with bias, public confusion, and the influence of the agricultural and dairy industry on nutrition science and research has all contributed to our underestimation of the role of nutrition across the spectrum of disease care. 

The science does seem to strongly support Campbell’s claims, even if they seem, at times in the book, to be a bit exaggerated. For instance, Campbell asserts that “our ability to treat cancer has not improved, despite an extraordinary amount of resources dedicated to this mission.” While cancer is still a leading cause of death, with nutrition as an integral component of its prevention and treatment, to say that we haven’t made any progress outside of nutrition science in its treatment seems to be a bit of a stretch. 

Further, not every type of cancer can be prevented or treated with nutrition (think childhood cancers, which could not possibly be the result of a lifetime of poor nutrition). Even by Campbell’s own estimation, and even if corrected for malnutrition, there would still be around 180,000 cases of cancer every year in the US that we would have to figure out how to treat outside of nutritional recommendations. 

Campbell also states that “not a single US medical school trains doctors in nutrition.” A quick look at the curriculum at my local medical school—The University of New England College of Osteopathic Medicine—shows classes devoted specifically to nutrition. 

Having spent decades with fellow researchers and scientists challenging the legitimacy of his work, Campbell might (justifiably) feel the need to make categorical statements such as these, but it can come across as dogmatic and exaggerated—which isn’t necessarily helping his case. 

Still, Campbell seems to be largely correct in that nutrition takes a back seat in the US in terms of both disease care and the education of our health care providers. And the public remains just as confused, as conflicting information is presented, nutritional guidance neglects the science (particularly in regard to protein consumption recommendations), and fad diets come and go. 

As just one example, consider that in 2015 the International Agency for Research on Cancer (IARC) of the World Health Organization labeled processed meat as carcinogenic and red meat as “probably carcinogenic.” However, as Campbell wrote:

“In a 2018 update on those findings [red meat as carcinogenic], the IARC reminded the public that ‘red meat contains proteins of high biological value, as well as important micronutrients such as B-vitamins, iron…and zinc.’ Why would IARC go out of its way to sing the praises of a food that they labeled ‘probably carcinogenic,’ when all the available evidence suggests a diet free of red meat could provide the same nutrients, if not more safely and effectively. Besides their long-time concern for chemical carcinogens and long-time disregard for nutrition, perhaps it’s also because they’re unable to see beyond the so-called biological value of animal-based protein, even when contradictions arise?”

Campbell then outlines a series of animal studies that show that animal protein—specifically casein, which is found in milk—has been found to be among the most powerful potential carcinogens ever discovered. 

And that’s why Campbell has consistently advocated for a simple, scientifically-backed whole foods, plant-based (WFPB) diet. The WFPB diet avoids the types of foods and nutrients shown to be carcinogenic and disease-producing and recommends the types of foods and nutrients shown to lead to better health and, in some cases, shown to be actually carcinostatic (capable of inhibiting the growth of malignant tumors). 

Why should this simple, common-sense diet consisting of fruits and vegetables (validated by numerous scientific studies) be so controversial? Because we’ve been repeatedly fed the myth that animal protein is of a higher quality than plant protein when, in fact, this is not the case. 

Despite the link between animal protein and disease, including cancer, we instead blame fat, cholesterol, environmental toxins, and anything and everything else simply so that we can delude ourselves into continuing to enjoy our favorite foods—while the marketing arms of the agricultural, dairy, and pharmaceutical industries are more than happy to appease these delusions. 

The underlying problem here is the reductionist nature of nutrition research and the search for single nutrients as the cause of health or disease. As Campbell explains, nutrition and metabolism are too complex to be fully understood in reductionist terms, and it’s more beneficial to look at overall eating habits and the correlations between complete diets and health. 

When you do, you can see that Western diets correlate highly with disease and cancer, and that the staple of Western diets is animal-based products. Denying this link—on the grounds that it is not “conclusive”—is like denying the link between smoking and lung cancer. Clearly, there is something wrong with the Western diet when compared to almost any other. 

Campbell is asserting that animal protein is in fact the driver of the link between Western diets and disease and cancer, but, admittedly, there is some question as to whether he has the right idea here. While there is a correlation between animal protein and disease and cancer, people that consume large quantities of meat and animal products are also likely to consume large quantities of processed foods, refined sugars, and fats. Since it’s hard to tease out all of these ingredients and physiological reactions, it’s more than possible that processed foods, rather than animal protein, is the real driver of disease and cancer. Campbell seems to be too quick to dismiss this possibility (although there is laboratory research to support the case for animal protein as a driver of cancer growth). 

Either way, what’s incredible about the research in this book is that there has not been a single study that links whole plant foods with any increased prevalence of disease or cancer. It seems pretty clear that adopting a whole food, plant-based diet will decrease your risk of disease and cancer and that there seems to be no research available contradicting this claim. Therefore, even if you don’t want to give up meat, animal products, or processed foods entirely—as Campbell recommends—the degree to which you can replace these foods with plant-based foods is the degree to which you can improve your health.

The Future of Nutrition: An Insider’s Look at the Science, Why We Keep Getting It Wrong, and How to Start Getting It Right is available on