Answer to a Reader’s Question:

Many people are rightfully confused about the various ways that protein recommendations are established, and fail to know the main factors that have caused the confusion. Understanding the protein recommendations requires an understanding of the history of protein research and the serious bias that crept into the science over the years. From the beginning, there was a very strong bias that has emphasized the health importance of protein and this almost always meant animal-based protein. This bias arose even though the research results clearly showed in many cases that it SHOULD NOT be emphasized. Nonetheless nutrition researchers still emphasized higher consumption of protein because it was the “sign of civilization itself” as was said in the early 1900s and, further, that those who did not consume these generous amounts of protein (i.e., meat) were “of an effeminate nature”!

Researchers continually pushed the protein idea and continually found ways to develop methodologies and algorithms to ‘show’ that higher levels of protein were advisable. The whole concept of protein “quality” was devised so that it could be said that animal protein was high quality and plant proteins were low quality when, in fact, the concept of quality only indicated a biological efficiency of utilization per unit protein consumed. Naturally, animal-based proteins more nearly mimic our needs because they are composed of the right ratio of amino acids, thus are used more efficiently. But these studies were mostly based on animal production research that served the farm community (also served for my PhD thesis!) far more than it served the interests of human health. More efficiently used “high quality” proteins also efficiently grow cancer cells as well!

However, it’s important not to miss the really bizarre point that the current US dietary guidelines advocate an upper limit of 35% of calories as protein that is supposedly consistent with minimizing chronic diseases. The only way that one can go this high is to be a virtual carnivore. The correct recommended intake is around 8-10% protein (not 35%!) which can be easily supplied by a good whole foods plant based diet. Even potatoes will do the job alone.

So, it’s back to the question of how and why and who is recommending these ridiculous numbers. The first time that these new high limits appeared was when a top consultant to the dairy industry, was chairing the Food and Nutrition Board that was responsible for the report. That report was funded by the dairy industry-based Dannon Institute, among other corporate benefactors who, accidentally I suppose, rather liked these high protein recommendations.

This is where Dr. Caldwell Esselstyn’s research that was focused on low fat intake and my research that was initially focused on lower protein intake converged, pointing to the elimination of animal based food consumption that was so highly correlated in international studies with Western diseases.


Why China Holds the Key to Your Health

I have been a researcher, lecturer, and policy advisor in the field of diet and cancer for nearly 45 years.

Since 1963, primarily from an academic position, I have seen the many faces of establishment science and have been both rewarded and distressed by what I have witnessed. I have seen a vast increase in consumer nutrition information and, regrettably, an almost equal increase in consumer confusion. One week we hear that eating meat increases our risk of colon cancer, the next week the exact opposite. One news report states that dietary fat is not related to breast cancer, another says it is. It seems to me that public confusion has grown far beyond acceptable limits.

In the 1980s, I was invited by Senator John Glenn’s U.S. Senate Committee on Governmental Affairs to offer an opinion about why there is so much confusion. My opinion then and now is that we tend to think so specifically about ideas and products that we fail to comprehend the main message. We stare fixedly at the trees and miss the forest. Specific ideas and products provide immediate money for the entrepreneur, grant money for the scientific researcher, and some degree of presumed “certainty” for the educator and publicist. They do not necessarily promote good health. Despite all our products and proclamations, more people are overweight in the U.S. than ever before. By the latest count one out of every three adults is overweight, an increase from one in four in the late 1970s.

The real aim of science is to advance knowledge about what makes you healthy, reduce your confusion, and alleviate human suffering. When I look at these problems strictly from the science point of view, I know there can be no quick intellectual fix. But I also know that the present confusion is beyond reasonable limits and something new is required. Thus, my colleagues and I felt that a newsletter of a different kind could provide a starting point. From this was born the idea of Nutrition Advocate, a newsletter advocating a diet based on a variety of quality plant foods and providing simple explanations so you can make reasonable decisions at your own pace.

As practicing scientists and researchers, we believe that we have done our homework. The science presented in these pages is the best that we can provide. Much of our research is based on the Cornell-Oxford-China Study (“China Project”), the most comprehensive survey of the connection between diet and disease in world medical history. The New York Times hailed this investigation, directed from Cornell University, as the “Grand Prix of all epidemiological studies.” These discoveries have vigorously challenged and altered existing conceptions about nutrition and health. We are now prepared to share more of these findings so you might join us in our excitement.

Why We Went To China

Previous studies relating nutrition to degenerative disease have mostly been limited to consideration of single factors and single diseases. Yet even when large surveys have been taken, they have generally produced mixed results. This is because these studies have largely been conducted in the developed world, where everybody eats more or less the same thing.

The China Project offers a rare opportunity to study disease in a precise manner because of the unique conditions that exist in rural China. Approximately 90% of the people in rural China live their entire lives in the vicinity of their birth. Because of deeply held local traditions and the absence of viable food distribution, people consume diets composed primarily of locally produced foods. In addition, there are dramatic differences in the prevalence of disease from region to region. Various cardiovascular disease rates vary by a factor of about 20-fold from one place to another, while certain cancer rates may vary by several hundredfold.

These factors make rural China a “living laboratory” for the study of the complex relationship between nutrition and other lifestyle factors and degenerative diseases. As a result, the China Project is the first major research study to examine diseases as they really are, multiple outcomes of many interrelated factors.
These factors make rural China a “living laboratory” for the study of the complex relationship between nutrition and other lifestyle factors and degenerative diseases.

When Is an Illness Normal?

The data from the China Project suggest that what we have come to consider as “normal” illnesses of aging are really not normal. In fact, these findings indicate that the vast majority perhaps 80 to 90%of all cancers, cardiovascular diseases, and other forms of degenerative illness can be prevented, at least until very old age, simply by adopting a plant-based diet.

In China, we found people whose diets ranged from being very low in fat (6% of calories) and almost entirely made up of foods of plant origin, to diets that contained significant amounts of animal products and even much higher amounts of fat (24% of calories). Dietary protein also varies across China. When we compare people on diets that are virtually nil in animal protein with those for whom animal protein is upwards of 20 to 30% of the total protein intake, the cholesterol levels go, on average, from around 90 mg per 100 ml to about 170 mg per 100 ml (see chart, below). Such an increase in cholesterol is associated with the emergence of the cancers and heart disease that increasingly plague the world’s developed nations.

Protein Key to the Cholesterol Dilemma

Earlier studies have provided impressive evidence that when a reduction in fat is compared to a reduction in protein, the protein effect on blood cholesterol is more significant than the effect of saturated fat. Blood cholesterol levels can be reduced by reducing dietary animal protein and exchanging it for dietary plant protein. Some of the plant proteins, particularly soy, have an impressive ability to reduce blood cholesterol. I really believe that dietary protein both the kind and the amount is more significant as far as cholesterol levels are concerned than is saturated fat. Certainly it is more significant than dietary cholesterol. While we don’t know how animal proteins have this effect, we do know that animal protein has a quick and major impact on enzymes involved in the metabolism of cholesterol.

I can understand why some of you may not want to consider that animal protein creates the same problems as excess fat intake, but it turns out that animal protein has many undesirable health effects. Whether it is the immune system, various enzyme systems, the uptake of carcinogens into the cells, or hormonal activities, animal protein generally only causes mischief. If you are switching from beef to skinless chicken breast and other animal-based food simply to reduce your intake of fat, it is my opinion that this may be a start, but it is not a solution. Even lean cuts of meat still contain around 20-40% of total calories as fat, or sometimes even more. You may get your fat intake down a bit, but your protein intake is not going to change.

Change is the Name of the Game

Personally, since coming upon these findings, my family and I have managed to change our diets substantially. I know what it’s like to eat meat. I was raised on a dairy farm and I milked cows from the time I was 5 until I was 21. When I went away to school, I eventually got my Ph.D. in animal nutrition at Cornell, where I worked on a project to produce animal protein more efficiently. So both my personal life and my professional life were entirely on the other end of the research findings that we’ve been getting.
Blood cholesterol levels can be reduced by reducing dietary animal protein and exchanging it for dietary plant protein. Some of the plant proteins, particularly soy, have an impressive ability to reduce blood cholesterol.

We started changing our diet when our children came along, and we have been changing ever since. In the short run, people who are accustomed to a high-salt, high-fat diet are not going to like healthier foods at first. But if you have a little patience, you will find that after two or three months, perhaps longer, you will pick up new tastes. Tastes do change. You will then discover that you are happier and more fit than ever before. In Nutrition Advocate we will provide the science to help you make the right decisions.

Nutritional Simplicity

In our next issue, I will begin to share with you some of the consequences of eating a typical American diet, along with a few provocative ideas about what’s missing in much of current gene research. The news reports telling you the way your genes determine your chances for getting cancer or other ailments are only telling you half the story. I’ll be filling in some of the “missing ingredients” in our next issue and give you some nutritional clues for ways you can help beat the odds, no matter what kind of genes you have.

East/West Cholesterol Report: China’s high is almost equal to the U.S. low!

With interest in diet and nutrition increasing at an unprecedented pace, I find that I’m asked to travel much more than in earlier days. I recently returned from England and Russia, where I was heartened to see the burgeoning interest in good nutrition. In England, where I serve as Senior Science Advisor to the World Cancer Research Fund (WCRF), I joined a group of senior researchers to comb through research grant applications from the very best scientists. WCRF, in my view, has taken the lead role in the world today to promote education and research on diet and cancer. After meeting in England, I flew on to Russia, where I joined several colleagues who are actively helping to restructure Russia’s biomedical science organizations. How very heartening to see so many at work in this troubled country making the link between diet and disease. It is my hope that more of the well-established scientific research institutions will take notice of this turn in events, so that all of us can more effectively chart a clearer path to wellness.
The message of the China Project is one of simplicity. You might say we are primarily interested in the symphony, secondarily interested in the individual musical notes

The message of the China Project is one of simplicity. You might say we are primarily interested in the symphony, secondarily interested in the individual musical notes. We believe the notes are most meaningful when perceived within the larger composition, especially when the symphony represents the very essence of our planetary well being. We must take more seriously the comprehensive effects of whole diets, rather than randomly tracking the misleading effects of individual nutrients and other odd chemicals. The time for making these linkages is now. The China Project data rigorously challenge many of our long-held nutritional assumptions and offer immense opportunities for improving our dietary habits on a global scale.

T. Colin Campbell is the Director of the Cornell-Oxford-China Diet and Health Project. He was trained at Cornell (M.S., Ph.D.) and MIT (Research Associate) in nutrition, biochemistry and toxicology. He presently holds the endowed chair of Jacob Gould Schurman Professor of Nutritional Biochemistry at Cornell University.


Brody, Jane, “Huge Study of Diet Indicts Fat and Meat,” The New York Times, May 8, 1990.

Chen, J., Campbell, T. C., Li, J., Peto, R. Diet, Life-Style and Mortality in China. A Study of the Characteristics of 65 Chinese Counties. Oxford, UK; Ithaca, NY; Beijing, PRC; Oxford University Press; Cornell University Press; People’s Medical Publishing House, 1990. 894 pp.

Dr. T. Colin Campbell has been at the forefront of nutrition research for over forty years. His legacy, the China Project, has been acknowledged as the most comprehensive study of health and nutrition ever conducted. Dr. Campbell is the Jacob Gould Schurman Professor Emeritus of Nutritional Biochemistry at Cornell University. Dr. Campbell also serves as the President of the Board for the T. Colin Campbell Center for Nutrition Studies and is featured faculty in our highly acclaimed, Plant-Based Certificate and our online heart course, Nutrition for a Healthy Heart.

How Sweet is a Sweet Potato? Pretty Sweet!

Sweet potatoes are a super food that I have only recently come to appreciate. When preparing my lecture on heart disease epidemiology for ournew eCornell course, I found reports of several traditional cultures known for avoiding heart disease that subsist largely on this delicious tuber. In fact, a 1978 paper[1] cited a dietary survey finding that sweet potatoes supplied about 90% of total calorie intake in the traditional subsistence culture of the Papua New Guinea highlanders. 90%! Sinnett and Whyte write, “Indeed, non-tuberous vegetables accounted for less than 5% of the food consumed, while the intake of meat was negligible.” There was no evidence of malnutrition from this diet and no evidence for hypertensive heart disease.

Here are some facts to chew on. If HALF of your diet was solely baked sweet potatoes with no salt, you would get all the nutrients in the table. To top it off: you get all this in a package with a lower glycemic index than white potatoes and many grains[2].

Nutrients in 1000 calories of sweet potatoes (about 10)[3]

Percentage of daily requirements (2000kcal diet)*

* Nutrient amounts calculated from USDA, reference 3, using the average daily requirements listed on


  1. Sinnett P, Whyte M. Lifestyle, health and disease: a comparison between Papua New Guinea and Australia. Med J Aust 1978;1:1-5.
  2. Willcox DC, Willcox BJ, Todoriki H, Suzuki M. The Okinawan diet: health implications of a low-calorie, nutrient-dense, antioxidant-rich dietary pattern low in glycemic load. Journal of the American College of Nutrition 2009;28 Suppl:500S-16S.
  3. USDA National Nutrient Database for Standard Reference, Release 26. In: U.S. Department of Agriculture, Agricultural Research Service; 2014.
Thomas M. Campbell, MD is executive director of the T. Colin Campbell Center for Nutrition Studies and a practicing, board-certified family physician at the University of Rochester. He is co-author of The China Study and author of the upcoming book, The Campbell Plan: The Simple Way to Lose Weight and Reverse Illness, Using The China Study’s Whole-Food, Plant-Based Diet.

A Health Disaster in the Making

In 2002, the Food and Nutrition Board (FNB) of the National Academy of Sciences (NAS) released their most recent recommended nutrient intakes.

Since 1943, the FNB has been telling us how much of each nutrient to consume, in the form of the Recommended Daily Allowances (RDAs). This Board, and its companion Dietary Guidelines Committee of the United States Department of Agriculture (USDA) that translates the FNB recommendations into practical food guides, create what is generally known as national nutrition policy. The influence and responsibility of these two panels is omnipotent and awesome. Numerous government-supported programs use these recommendations, including the school lunch program, the Women, Infants and Children (WIC) program, and Medicare-reimbursed meals for hospitals and nursing homes.

Having been a member of several diet and health policy-making expert panels over a 20-year period, until 1997, I harbored the naïve view that these panels were dedicated to the promotion of consumer health. I no longer believe this.

This report makes clear that the food and health practices that have brought us so much illness in recent decades will remain intact, perhaps even made worse. Two of three Americans are overweight and ‘adult-onset’ diabetes is now attacking our children. The long-time high rates of various cancers and cardiovascular diseases remain mostly impervious to change. We’re paying increasing amounts of money – lot’s more – and getting less. An even faster food nation awaits us, to paraphrase Eric Schlosser’s book.

In this most recent FNB report, we see some brand new recommendations, especially for the macronutrients (protein, carbohydrates, fat) that supply our calories. Instead of recommending nutrient intakes that are based on single RDA numbers as in past reports, this new report allows for ranges of intake that are said to “meet the body’s daily nutritional needs while minimizing the risk for chronic disease”. The main conclusions are highlighted in the executive summary and news release. “Adults should consume 45 to 65 percent of their total calories from carbohydrates, 20 to 35 percent from fat [up to 40% for children], and 10 to 35 percent from protein.” The report also says that we can consume up to 25% of our energy from added sugars found in sweets, pastries and soft drinks. Expressing optimal nutrient intakes as ranges is certainly more informative and realistic than were the single-number RDAs of past reports. But defining and setting these boundaries must be based on a careful and complete review of the evidence.

Let’s consider the case for protein, which symbolizes our preferences for food more than any other single nutrient group. The lower limit of 10% dietary protein is equivalent to the RDA of previous reports, first published in 1943. Indeed, this quantity is already above the theoretical requirements of almost all people. Professor Henry Sherman of Columbia University was largely instrumental in establishing this recommendation, based on a 1920 summary of about 100 subjects. He suggested that about 8% of dietary calories was enough but offered that for those “whose temperaments lean toward a higher protein intake”, a range of 10-15% might be in order.

However, because we practically worship protein-rich foods, the vast majority of us have decided to ‘pig out’ within the range of 11-22% dietary protein, with most of this extra protein coming from animal based foods. But we do so at considerable health risk, partly due to the excess protein itself and partly due to the kinds of foods that mainly provide such a high protein intake. Only a very few of us consume diets as high as 22% protein, generally for ‘pumping iron’.

Now, we are to understand the astounding conclusion that consuming diets as high as 35% protein(!) lies within a range of “minimizing the risk for chronic disease”. The disease-promoting implications of this new recommendation are staggering. There is voluminous evidence showing that consuming diets ‘only’ as high as 20-22% protein increases the risk of many serious diseases. But the FNB committee says that we can go to an even higher level of 35%, without ill effect.

Increasing animal-based protein consumption up to dietary levels well below 35% associates with higher blood cholesterol levels and more atherosclerotic plaque (even more than saturated fat), greater risk of cancer (caused by multiple mechanisms), greater bone loss of calcium and higher risk of osteoporosis, greater risk of Alzheimer’s disease, and greater formation of kidney stones, to name just a few chronic diseases that the FNB committee mysteriously ignores or claims to remain unaffected by this high protein intake. These ignored findings are not the results of a few isolated experiments. In most cases, they represent a summary of multiple studies, some of which are even many decades old.

This report makes other macronutrient recommendations that are equally troublesome. It is said, for example, that we can safely consume up to 25% of our daily energy as added sugars, meaning candies, soft drinks, sweetened food products and pastries, some products of which are also loaded with added fat. The committee acknowledges that obesity has become a health problem of great concern but then disingenuously blames ‘high carbohydrate’ diets for the problem. Like certain popular diet book authors, they err in this view because they fail to distinguish between the health benefits of complex carbohydrates (e.g., whole grain products), which were previously recommended, and the health problems of refined sugars and starches (e.g., sweets, pastries and refined flour pastas), which were never recommended by previous reports.

The FNB report also lifts the lid on dietary fat. Previous reports recommended keeping dietary fat under 30% but this recent report now says that we can go up to 35%, even up to 40% for children.

Groups who use this report will be encouraged to consume the same diet of sugar and starch type carbohydrates and high fat and animal-based protein foods now making us fat and fertilizing the growth of our chronic diseases. Admittedly, past recommendations have not stemmed the rising tide of chronic degenerative diseases during the past few decades. But these recommendations, themselves, were lukewarm, partly because of a perception of insufficient evidence and partly because of a timidity of confronting a growing food industry offering up a buffet of protein-rich, fat-rich, processed foods. We now have overwhelming evidence to show that a plant-based diet of whole foods, low in fat and protein and high in complex carbohydrates (but not in refined carbohydrates!), is associated with substantially lower rates of these diseases. Furthermore, we also now have substantial information on how these foods produce their biological benefits.

This report represents a backlash against emerging but convincing evidence that now terrifies the food and drug industry. However, it does its best to remedy this problem by cooking up a bunch of sweets for these industries. Corporate health will undoubtedly be enhanced but consumer health will undoubtedly be set back, perhaps for decades.

I take no comfort in discovering a very troubling corporate influence in the making of this report. For example, the Chair of the sub-committee responsible for setting the upper limits for these macronutrients departed the panel before its conclusion for an executive position with the world’s largest food company who will find these goodies especially tasty for their bottom line. His replacement was someone who openly acknowledges that he knows very little about nutrition, as this has not been his field. The FNB Chairman, who helped select panel members, is a well-known associate of the dairy industry. During his chairmanship of the companion Dietary Guidelines Committee, his industry ties regrettably became known only through court-enforced legal action. I also find it troubling that this report received funding from food and drug companies who will find its contents especially tasty.

I do not recall such egregious conflicts of interest during my tenure with such advisory panels. It is time that advisory panels and their parent organizations who develop diet and health policy take more responsibility of fully revealing all potential conflicts of interest. Further, I would urge that they consider disallowing researchers with serious conflicts from holding leadership positions on these panels. The public deserves far more than they are getting from this very important report.

Dr. T. Colin Campbell has been at the forefront of nutrition research for over forty years. His legacy, the China Project, has been acknowledged as the most comprehensive study of health and nutrition ever conducted. Dr. Campbell is the Jacob Gould Schurman Professor Emeritus of Nutritional Biochemistry at Cornell University. Dr. Campbell also serves as the President of the Board for the T. Colin Campbell Center for Nutrition Studies and is featured faculty in our highly acclaimed, Plant-Based Certificate and our online heart course, Nutrition for a Healthy Heart.

RDA’s: Time to Peel Back the Labels

RDA’s: Time to Peel Back the Labels

Every once in a while, when strolling through the grocery store with my wife, Karen, I get up the nerve to look at those nutrient profiles on the side of the package.

Even though I was recently on a National Academy of Sciences committee on food labeling, responsible for redesigning this information, I still wonder what all this really means. The Recommended Daily Allowances (RDAs) are the nutrient levels considered by governments and industry throughout the world to be desirable for good health. But how desirable are they really? Let’s see what’s beneath the label.

To begin with, the RDA is just what it says it is. It’s a recommended allowance; it’s not a minimum requirement. The underlying assumption is that if you consume exactly the RDA level for a specific nutrient, there is a very high (97-98%) probability that you will exceed your actual minimum requirement. In other words, to play it safe, the RDA represents a substantially higher intake than what you need.

Why then do so many people believe that they must consume an intake at least equal to or even higher than the RDA? This is because the food and vitamin supplement companies carefully coach us to believe in RDAs. For them, this idea makes money, and lots of it. It’s an easier “sell” to say that the nutrient content per serving of a company’s particular product comes closer to the RDA than that of their competitors.

The idea of RDAs started reasonably enough when a few folks began asking about the nutrient value of military rations during World War II. The decision was handed over to the Food and Nutrition Board of the National Academy of Sciences. Ever since, this authoritative body has stood at the helm of so-called “good health” by issuing their revised listings every five years. But let’s look at what these reports are actually saying. First, there is an RDA given for each nutrient, broken down according to age and sex. Each RDA represents the minimum intake for a “single” nutrient, along with an upward adjustment thrown in for good measure. While this presumably provides us with a “safety check,” no range is given with high and low numbers. This single bottom number, already higher than the minimum requirement, suggests to many, “the more, the better.”

Making Money from RDAs

Folks, it just ain’t so. Witness the recent beta carotene revelations. You may recall that this study was halted when scientists reported the death rate from lung cancer was 28% higher among the participants who had taken the massive doses of beta carotene and vitamin A than those who had taken a placebo, and the death rate from heart disease was l7% higher. At least in countries like the U.S., where gorging is often the norm and vitamin supplements are treated as medicine, we ought to be thinking more about nutrient excesses than deficiencies. Note especially vitamin labels boasting such claims as “high potency” or “super-stress” formula. This problem is compounded when we forget about good wholesome diets (of plant-based foods) where nature works wonders in her own way.

Another serious problem goes something like this. In the absence of adequate scientific information, scientists establish RDAs which tend to be biased in favor of conventional levels of intake. But what are these “conventional” intakes? It’s this: they are those intakes which characterize diets that are high in fat, low in fiber, and high in animal proteinthe very kind of diet which causes us so many problems. Thus, a tendency exists to keep RDAs for plant-based nutrients low, while keeping animal-based nutrients high.

Even when we know it’s questionable, we find a very strong tendency to maintain the status quo. Vitamin C, for example (only available in plants), is given an RDA of 60 mg/day even though considerable information suggests that levels around 200-300 mg/day are more beneficial. And beta carotene, obtained almost entirely from plants, doesn’t even have an RDA. Generally, beta carotene is viewed as only a part of the “real” vitamin A, called retinol, which is found only

in animal-based foods. Dietary fiber, another plant-based nutrient, is relegated to the same non-category as beta carotene, and is similarly deprived of an RDA status. When it comes time to hand out RDAs, plant-based nutrients are either not assigned one or are given an RDA biased toward the low side. To register the higher, more appropriate intakes would suggest eating considerably more fruits and vegetablesa tough thing to do for meat and potatoes folks.

Standing on Shaky Foundations

By contrast, RDAs for animal-based nutrients are characteristically biased upwards. To take but one example, the RDA for calcium (at 800-1200 mg/day) is considerably in excess of the much lower intakes that are adequate for those on a plant-based diet. Probably a more accurate figure, based on our China Project surveys, would be closer to 400-­600 mg/day. Especially in the case of calcium, the amount of the nutrient needed is influenced by the type of diet consumed. That is, a high-dairy diet brings along baggage in the form of extra protein. And this extra protein causes calcium to be lost; thus more is needed. Why not try cutting down on dairy products so you require less calcium? In this country, about 60-­70% (on average) of total calcium intake is provided by dairy products.

RDAs have for a long time provided the so-called bedrock for dietary recommendations, such as the Basic Four Food Group guide, despite their shaky foundations. Used for so many years as a “good” general nutrition message by the United States Department of Agriculture (USDA), the Basic Four Food Group guide was devised to ensure adequate intakes of certain nutrients, especially those which supported high intakes of animal-based foods. As a result, scientists were inclined to “discover” that vegetarian diets were deficient in some nutrientscalcium, “good quality” protein, “good quality” iron, riboflavinwhen they were actually being judged against the biased RDA standards.

Heeding Mother’s Advice

Even though I believe that RDAs have mostly been an albatross around the neck of sound nutrition education, they may possess some value in defining nutritional profiles of large populations. That is, nutrient reference standards, such as the RDAs, can give a rough idea of a nation’s comparative nutritional health. But even so, I still wonder what useful purpose is served when nutrient intakes of a population are judged by reference standards prejudiced in favor of a low-fiber, high animal protein and fat diet.

Of all the dietary recommendations, RDAs are the oldest. In my view, they have been problematic from the start. Fortunately, the USDA’s Basic Four Food Group guide, with its emphasis on RDA standards, is now virtually dead. Still more fortunate is that we are now getting the U.S. Dietary Guidelines and the USDA Diet Pyramid, which pay less heed to the RDAs and which give somewhat more emphasis to plant-based foods, although this emphasis is still preciously limited. And then there are the newer Mediterranean and Asian Diet Pyramids, produced by a prominent well-heeled consumer based agency, which give considerably more emphasis to plant-based foods. I’ll comment on these newer nutrition guidelineswhere they succeed and where they failin an upcoming issue.

Progress is painfully slow in this arena where Big Science, Big Politics, and Big Business tell us what to eat. I rather still like that old advice of our mothers and grandmothers: eat your vegetables!


Campbell, T.C., “More Is Not Necessarily Better.” Natural History, 90:12-16, 1981.

Kolata, Gina, Studies Find Beta Carotene, Taken by Millions, Can’t Forestall Cancer or Heart Disease, New York Times, Jan. 19, 1996.

T. Colin Campbell is the Director of the Cornell-Oxford-China Diet and Health Project. He was trained at Cornell (M.S., Ph.D.) and MIT (Research Associate) in nutrition, biochemistry, and toxicology. He presently holds the endowed chair of Jacob Gould Schurman Professor of Nutritional Bio-chemistry at Cornell University.

Dr. T. Colin Campbell has been at the forefront of nutrition research for over forty years. His legacy, the China Project, has been acknowledged as the most comprehensive study of health and nutrition ever conducted. Dr. Campbell is the Jacob Gould Schurman Professor Emeritus of Nutritional Biochemistry at Cornell University. Dr. Campbell also serves as the President of the Board for the T. Colin Campbell Center for Nutrition Studies and is featured faculty in our highly acclaimed, Plant-Based Certificate and our online heart course, Nutrition for a Healthy Heart.
%d bloggers like this: