Transcript of Interview 1:

S.J.: We’re speaking with T. Colin Campbell, Jacob Gould Schurman Professor Emeritus of Nutritional Biochemistry at Cornell University. Dr. Campbell has received several prestigious awards for his work relating diet, nutrition, and diseases including the 1998 lifetime achievement award in cancer research from the American Institute for Cancer Research has authored or co-authored over 350 scientific articles. In the book the China Study: Startling Implications for Diet, Weight Loss, and Long-Term Health Dr. Campbell and his son, Thomas M. Campbell II cite over 700 peer reviewed published scientific studies which conclude that consuming an animal-based diet can aggravate many chronic degenerative diseases and even play a role in causing them, and conversely, eating a plant-based diet can act as a preventative and even supports healing.

S.J.: In your research, what switch did you use to turn cancer on and off?

T.C.C.: Originally our research involved experimental animals and a very specific sort of tumor model system, or cancer system, that we could describe and experiment with. I was specifically interested in the question concerning the effect of animal protein, but more particularly just the effect of protein on tumor development. We discovered that children in the Philippines who were consuming a lesser total amount of protein had fewer incidences of a certain kind of cancer, which is exactly the opposite of what was previously believed. Then there was a report in India using experimental animals that showed that the rats that got less protein had fewer tumors, so I focused on that question. These studies clearly showed the effect of protein on cancer development in these experimental animals.

S.J.: What kind of protein did you use?

T.C.C.: At first I didn’t pay a lot of attention as to what kind of protein we used; I thought protein is protein is protein. After we saw what dramatic affects protein had on the tumor growth and development, I started paying attention to what kind of protein it was. We used casein in our study, which of course represents about 85-90% of the total protein of cow’s milk. The results seemed to be specific of casein because when we ran trials using wheat protein and soy protein fed at the same levels that had turned on the cancer with the casein, those plant-based proteins did not have that effect. There is a major distinction between animal-based proteins, or more specifically in this case casein, and wheat and soy protein, or plant-based protein.

S.J.: Why are studies in rats particularly relevant to human cancer studies?

T.C.C.: There are numerous instances where studies done on one species do NOT translate to the effects in other species, and we can site these differences that exist between species as a given. However, rats are mammals as humans are and as far as their basic biochemistry and physiology is concerned, we can say with a great deal of confidence that at least 95-99% of the biochemical reactions that exist in a rat also exist in humans. So there is far more correspondence biochemically and physiologically speaking between a rat and humans or between one animal species and another animal species than what we’re generally willing to admit. In addition, we often want to know what is the dose relationship? That is to say, if we see a reaction in one species with a certain dose, we might not see the reaction to the same degree of response in another species at that same dose. A different dosage may be needed. Two things that must be taken into consideration: first, the dose of the agent that is being administered and second, the more qualitative characteristics of the response. Taking all that into consideration, rats and humans, in this case require about the same amount of protein to sustain health and their rapid growth rates are almost identical. This relevance between rats and humans has been shown before in other studies aside from our case.

S.J.: And again this was casein protein from dairy products, bovine or goat products.

T.C.C.: Well I can’t say for goat’s milk because we used cow’s milk.

S.J.: Isn’t casein found in goat [milk] products?

T.C.C.: Casein is found in virtually all milk products including human milk too, but there are other factors to be considered. Casein percentages can differ somewhat between species so its effects may not necessarily be exactly the same. Casein actually can differ somewhat between breeds of cows which can lead to slightly different responses. Differences and discrepancies certainly exist and administering casein in one species will not always create exactly the same degree of response as it does in another species, but compared to the extreme results from the wheat and soy protein, casein is casein is casein. If it’s going to have any effect at all, the casein is going to increase tumor development. It will never decrease tumor development. A large amount information regarding the casein/tumor incidence has come out since we have finished our work, and is fully supportive.

S.J.: Why were tumors in the liver studied?

T.C.C.: Liver cancer is common in some areas in the world in people and not so common in other areas, such as more Western countries. Often times the difference between liver cancer from one country to the next, usually between a poor country and a rich country, really has to do with another agent. Most commonly this is exposure to a hepatitis virus, in this case, Hepatitis B or Hepatitis C. If an individual remains chronically infected with these viruses, the risk for liver cancer will be significantly raised. Poorer countries have more virus contamination, more exposure, and therefore you have a much higher proportion of the population that is susceptible to liver cancer to begin with. We know that for a cancer such as liver cancer to grow in people who are chronically infected, there is going to be a large influence from nutritional intake. In this case, we’re talking about casein as the influencing factor. Liver cancer was a good choice to study not only because that was the cancer that I was observing in people, but it has become common in experimental cancer research over the last three or four decades or longer to study to the effect of carcinogens on liver cancer as opposed to other kinds of cancers in experimental animals because liver cancers tend to grow rather rapidly. We can study their biochemistry more effectively. Because of this, there is a huge body of literature on the mechanics of tumor development in the liver as opposed to other tissues. There are all kinds of reasons, part of it’s tradition, but part of it’s really, I think, rational thinking.

S.J.: Were the results applicable to other organs?

T.C.C.: Yes, studies that were being conducted by a friend of mine at the University of Illinois Medical Center in Chicago over some years about the time that we were doing our studies on liver cancer was able to show that higher intakes of casein actually enhanced the development of mammary tumor development or breast cancer development. There were other studies showing that higher protein intake increased pancreatic cancer development as well. Pancreas, breast, and liver were the cancers that were chiefly studied at the time. I think our studies were probably more extensive and robust than the other studies but nonetheless when people did choose to study the effect of protein on cancer development that is what they saw—an increase in tumor formation. We now know that there are certain things that go on that are likely to affect cancers in all the organs as far as animal protein intake is concerned.

S.J.: So in the lab were you recreating the process by which precancerous legions accumulate in the body because of random mutations or from exposure to carcinogens like aflatoxin?

T.C.C.: Aflatoxin is one of the most potent if not the most potent chemical carcinogen to cause liver cancer in rats, which makes it a good model to study. The initiation of cancers can occur in various ways, virtually all of which have to do with perturbation or disruption of the genetic material in one fashion or another. When chemical carcinogens enter the body and get metabolized, they bind to the DNA in specific spots. After becoming metabolized, the carcinogens disrupt prominent, key genes that might be involved with cancer development. Viruses like Hepatitis B virus and Hepatitis C virus do the same thing: a part of their DNA comes in and inserts itself into the DNA of the rat, the host DNA. In addition to chemical carcinogens, radiation may give rise to what we call spontaneous mutations from time to time and there are other agents as well that are cancer causing. That whole process is referred to in the research community as cancer initiation. There are various agents that can initiate a normal cell to convert to an early cancer cell. In fact, we have conversion of normal cells to cancer cells going on in our tissues to some extent, for our whole lives. That is probably true for most of us, if we’re exposed to environmental issues, concerns, and things. But that’s a given, that is part of the whole process, partly natural, partly it probably occurs more prominently in an industrialized society, unfortunately. The real question is what happens to those early cancer lesions that initiate that way? Do those cells stay there? Do they get corrected? Well, a big percentage of the cancerous cells get repaired and reabsorb back, but some of them stay in the liver and they can remain latent. These cells don’t cause any problems as long as we’re keeping with the right kind of nutrition, and that’s where the protein thing comes in. Protein, animal protein in particular, behaves like fertilizer, fertilizing these pre-cancerous cells so that they grow. We can have weed seeds in a garden and they never grow to create weeds if we don’t give them water and fertilizer. It’s the same idea here with the cancerous cells and the animal protein.

S.J.: So in the lab all the rats were constantly challenged by the same aflatoxin dosage. You then gave some of the rats a higher amount of protein, in this case casein, and those rats got tumors and the other rats did not. What was the percentage on that?

T.C.C.: That is correct. Initially, the level of protein that we were using was 20% of the total calories of the diet, which is generally considered to be normal, traditional, regular.

S.J.: And what percentage of calories do Americans get?

T.C.C.: Approximately 90% or 95% of the Americans are consuming somewhere in the range of about 11% to 24% of their calories from protein daily. It’s a little higher today than it was when I first wrote the book, but the average protein intake in the American diet is about 18% right now and about 70-75% of that protein is from animal sources. In the case of these animal experiments, this is a situation that is really comparable to what a lot of humans are now actually consuming.

S.J.: And yet that animal protein isn’t all milk protein?

T.C.C.: Right, correct. I wish we had had the time and money to test all the other animal proteins, but I don’t think it would really be necessary because when comparing animal proteins and plant proteins there are other effects such as changing blood cholesterol levels, and varying degrees of calcium leakage. Animal proteins all tend to behave similarly and we know a lot about them now. I think if we were to test a whole bunch of other animal proteins like meat proteins, egg proteins, and so forth I would bet anything that any animal protein tested in this amount would in fact turn on cancer, even though final testing hasn’t been done on all types of animal protein. It’s sort of like asking does cigarette smoke really cause cancer or not. No one has really proven in a human study that cigarette smoke really causes cancer in humans.

S.J.: It’s hard to prove anything in biological terms.

T.C.C.: That’s right. If we want that 100% proof for all conditions we’re not going to get it. One has to operate on the odds.

S.J.: What’s fascinating is that for the rats that had tumors and were still under aflatoxin challenge, you decreased the percentage of casein fed and what happened?

T.C.C.: Those tumors grew no further and from the evidence that we had it looked like they reversed which is fascinating. The way the casein was working was promoting the development of growth in tumors, which is actually the second phase of cancer development- promotion. During the promotion stage of cancer development other studies have shown that it’s largely reversible and the classic case is with cigarette smoking. Most of the cancer that occurs as a result of smoking cigarettes is occurring because of the promotion of the early tumor lesions. When people stop smoking their risk of getting lung cancer goes down; it may take a few years but it reverses. Being aware of that fact, I was not surprised to see the results that we did. When we changed the level of protein in these rats from 20%, even after the tumors had already started to grow, we switched them to the 5% casein diets. The tumors essentially stopped growing on the evidence that we had. This was very exciting. We got to a point where we were demonstrating that we could turn on and off tumor growth, just by giving them this 20% and 5% casein diet.

S.J.: What does that imply for supporting healing from challenging diseases, like cancer?

T.C.C.: I’m not sure what you mean by supporting healing.

S.J.: I don’t want to say treatment, what is the proper word? Because reducing animal products is not a treatment —that is why I am saying support the body’s healing.

T.C.C.: Well it’s an interesting word and concept. I’m going to suggest that I think you really are referring to treatment, because a lot of people would agree that diet certainly can prevent certain diseases, like cancer and heart disease. Most people agree that consuming the right kind of diet will prevent diseases. It turns out that that same kind of diet that prevents the disease is now being shown to actually reverse advanced disease, and that’s the definition of treatment. In the case of heart disease for example, Dr. Caldwell B. Esselstyn, Jr. took patients with advanced heart disease who were being told by their doctors to go home and prepare their final papers and put them on a diet that reversed the heart disease—he showed it very clearly. Dr. Dean Ornish did something similar with Type II diabetes. And there is some evidence for cancer too. So I’m going to go out on a limb on this one and say that if your word healing can mean treatment, I’m going to suggest that it’s treatment. We need more work in this area, but it’s very clear from this evidence that we can both restore health and prevent health from deteriorating with this kind of diet.

S.J.: Is it bottom line that the body is doing the healing and it’s essentially healing itself?

T.C.C.: Yes, I think I would agree with that. If the body is given the right resources, which means the right kind of food, the right kind of air, and the right kind of water, and if other conditions are made right, the body I guess you could say is healing itself, which is a nice thought.

S.J.: And it’s not being challenged by cancer promoters in animal products?

T.C.C.: Exactly.

S.J.: So plant proteins—like that from rice, wheat, or soy—do not cause this problem. How come only animal protein causes this?

T.C.C.: Well, there appear to be multiple so-called mechanisms or explanatory mechanisms, as we like to say in research. To get to the point of your question, we actually did look for so-called mechanisms as to how and why this happens. In the late 70s, when we were still working on the initiation stage and before we got involved in the promotion stage, I was amazed that every time we looked for a mechanism, biochemically speaking, we found one. Higher protein diets increased cell replication, that was very clear. We showed this in 1972 and it corresponded with what some other research that people had done.

S.J.: And not plant protein?

T.C.C.: Well, we were using animal protein at the time and so everything that we were doing at that particular time was with casein. We were simply asking questions as to how it worked. Animal protein increased the transport of the carcinogen into the cell, it increased the enzyme principally responsible for activating the carcinogen, and it changed many other parameters, and all of this was acting in concert, which is really an amazing thought. We were not talking about any specific mechanism but really a cluster of highly integrated mechanisms acting in symphony, in harmony, to create the effect. And that was with just one phase of the cancer development. When we turned our attention to the promotion question, we then also learned that there are multiple mechanisms there too. Since we stopped that research and I have been watching the literature as to what other people are doing, there are still more mechanisms emerging. To answer your question, cancer promotion works through a whole family of mechanisms, biochemically speaking and physiologically speaking, and whether it’s through hormones traveling around the body, it’s an amazing effect. This observation probably excites me more than any other single observation about the relationship between animal protein intake and of disease response like cancer. When one actually begins to look at the mechanisms behind the fact that high protein gives more cancer, or high protein gives more blood cholesterol, or high protein does this or that or something else and realizes that there is a symphony here at work, a symphony of reactions. I find it almost overwhelming that all of this stuff seems to work together and everything goes wrong.

S.J.: Just as when the body is working well to support healing, normally the lesions get reabsorbed by the body, in a whole symphony of immune responses, when the immune system is robust.

T.C.C.: Absolutely, right, exactly, and the immune system as you know is made up of enormously complex list of components all working together. And again, how ever you want to look at this, it seems that all these pieces of the puzzle all get together and decide how are they going to manage this and they work together. The converse of this is that if the body is healthy, healing itself perhaps or at least maintaining its health, these reactions are going on simultaneously, that’s a symphony to create health.

S.J.: So when the promoters get removed, the tumors can get reabsorbed by the body and if the body doesn’t have any challenges and we’re in good health without any tumors, then it’s actually quite difficult for cancer to get a foothold.

T.C.C.: Exactly. Exactly, that is precisely it. If you create the right biochemical and physiological environment, in other words take away the promoters, take away the offending agents, and let the body do its miracle in the way it wants, the chances of things going wrong are very, very remote.

S.J.: Which may be why cancer is so prevalent in industrialized climates and industrialized countries with the diets so heavily laden with animal products, the rich affluent diet, as compared with low cancer rates in countries that use more of a plant-based diet.

T.C.C.: Right, that is certainly true, I mean, rich countries consume rich food, and that so-called rich food is not the best food, it’s not the healthiest food. It’s high in animal products which changes the intake of a whole host of different kinds of nutrients, all of which tend to encourage disease formation.

S.J.: Is the difference between such countries a factor of 10 in percentage rates of cancer among the population, just as a ball park?

T.C.C.: Well, you kind of have to look at each cancer individually, rather than total cancer. It’s true for individual cancers you can find differences in the rates of cancer in different countries at least 10 fold if not in fact a 100 fold. It’s huge differences, really huge differences, as you look at the individual cancers. The reason you have to look at individual cancers, as opposed to just cancer generically is that in poor countries they have less instance of cancer when a more plant-based diet is consumed. However, there are other factors that come into play here, as we just mentioned before for liver cancer. In poorer countries, the hygienic environment is not so good, and the exposure to viruses and bacteria is higher, and maybe people are saving foods in ways that is not to their best interest. Essentially what you get in these poor countries is that they have a higher exposure to some kind of initiating agents, and so you have a higher proportion of people susceptible to get certain kinds of cancer. You will see in poor countries, for example, that incidences of breast cancer, colon cancer, cancers like that may be much lower, but you will see higher cancer rates for, let’s say, liver cancer, perhaps stomach cancer where they have no refrigeration and esophageal cancer, cancer of the throat. In each of those cases, if you look at those cancers individually, even the cancers that are fairly common in poor countries, and you ask yourself which cluster of factors is causing those cancers to be high, you’ll discover, of course, it’s the kind of agents you find in poor societies that are operating. In respect to nutrition and animal foods, you can thank God they’re not consuming animal foods, because if they were consuming animal foods…

S.J.: Under the challenges that they face…

T.C.C.: Under the challenges that they face, exactly, they would have a disaster. It’s interesting to see people coming from the poorer countries to the Unites States start consuming our diet. While they’re adapting to our diet, it’s more offensive to them than it is even to us. You’ll see an explosion of diabetes or an explosion of obesity amongst some of these people when they move into this more industrialized society. Our body basically is always trying to create health, given its resources, even when we provide the wrong resources, like when we’re living in the wrong environment, the body will still, from the biochemical point of view, try to do the best it can. Because it’s a matter of survival we will adapt to bad conditions enough to at least reduce the bad effects that would otherwise occur. We never completely eliminate it. If we live in a toxic, poisonous environment for some period of time, we all know we get something that goes wrong eventually, even though we may adapt in the short run.

S.J.: We get something eventually if we challenge ourselves with promoters of diseases?

T.C.C.: Yes.

S.J.: If we don’t, but we support robust healing and prevention then we’re ok?

T.C.C.: Yes, you are absolutely right, absolutely, absolutely.

S.J.: In The China Study, you and your son cite research showing that animal based foods increase people’s production of insulin-like growth factor 1, which stimulates reproduction and growth of cancer cells and inhibits cancer cell death by apoptosis, or self-destruction of the cell, especially in the ovaries, breast, and prostate. How does growth factor do that?

T.C.C.: It’s really not clear. These growth factors are acting like hormones; intracellular hormones to a great extent. As they come into the cell, they bind to a receptor protein. That receptor protein, in a sort of generic model, carries them from the cell membrane into the nucleus where the DNA is and delivers them to the nucleus. These growth factors then act on the DNA and switch on the expression of certain genes which actually stimulates a cluster of things to go on to eventually lead to growth of cells, or replication of cells. It does all these things, thus it’s being called a growth factor.

S.J.: Why does extra growth factor increase the chance of getting tumors in the reproductive system, in particular, by more than 500%, according to The China Study, your book?

T.C.C.: Well, I hadn’t really thought of it quite that way; that is an interesting observation. The growth factors, at least the growth factors that we’re generally talking about here, will be increased by consuming milk. When we’re infants, when we’re consuming human milk, mother’s milk, we’re at a point in time, our early development, where growth is important. Milk is the food that we choose to consume in the very beginning, this is nature. It’s promoting growth, and it’s particularly effective at doing this naturally. As we get older, to promote growth doesn’t make a lot of sense.

S.J.: Milk is better for babies.

T.C.C.: Human milk.

S.J.: Human milk is better for human babies.

T.C.C.: Exactly, cow’s milk for cow babies, or calves.

S.J.: And goat’s milk for goat babies.

T.C.C.: Exactly, so there is a period in our life when growth is important, it clearly is that is just part of the human cycle. But later that kind of growth, unless we’re repairing certain wounds or something of that sort, is not the kind of thing that we want to encourage.

S.J.: Do animal products increase the risk of fibroids?

T.C.C.: Yes, it seems to, that is just sort of a given, an understanding, but I can’t think of specific research where that’s been demonstrated. Fibroids, in their classic case, usually the fibroids you might see in the case of the uterus, uterine fibroids, tend to either create an environment for or are part of the development of uterine cancer. When fibroids begin to occur in a woman and are seen, it’s generally acknowledged that they have a higher risk for uterine cancer and so over the years women have had hysterectomies upon the discovery of fibroids like that. Now we know that dairy is the one food that really has a strong association with uterine cancer.

S.J.: Okay, so the uterine cancer association with dairy has been studied more than fibroids?

T.C.C.: Yes.

S.J.: So people are just inferring from the tight correlation with respect to cancer that milk products also promote fibroids.

T.C.C.: That’s it.

S.J.: What about other animal products? Meat, fish, chicken, pork?

T.C.C.: Well, if we just talk about protein what we find in the one example where this was done fairly thoroughly, was the effect of various animal proteins’ ability to increase blood cholesterol levels and promote the formation of atherosclerotic plaques. This was done in rabbits some years ago by the late Ken Carroll at the University of Western Ontario. He compared a whole bunch of animal proteins, a whole bunch of plant proteins and found that as a group, plant proteins tended to be associated with lower cholesterol levels. He found that animal proteins have something in common, higher blood cholesterol, which was quite distinctly different from plant proteins, even though there were some differences between different animal proteins. So to go back to your question concerning fish and other animal products to their effect, if we look at them in reference just to their protein content, and on the basis of the studies that have been done with certain outcomes, animal foods in general are going to cause problems. But by the same token, this raises yet another issue, and that is when people consume more animal foods they consume less plant foods in general, and when they consume less plant foods they’re taking away substances that otherwise would prevent. So what you get, in a given diet, if you try to generalize the whole thing, it’s the relative proportions of animal and plant based food is going to lead to good or bad things down the road.

S.J.: Could you please describe the Harvard Nurses’ Health Study?

T.C.C.: Yes, the Harvard Nurses’ Health Study, which is probably, arguably, the most prominent case control study that has been conducted over the years, had been ongoing since the 1970s. And in the early 1980s it was redesigned to collect dietary information. And over the years they became particularly interested in looking at the relationship between dietary factors and disease outcomes. Initially, it was breast cancer that they were primarily interested in but then subsequent to that they have worked in a lot of other diseases. And so in this cohort that they have been using, it now includes in excess of 100,000 nurses. They have been following these nurses for quite a long time now, since about the late 1970s and now they have the daughters of these nurses too. The study has become very big and it has been extensively funded. The last time I heard, over $125 million dollars had been spent on running that study, but at the same time they have been very good about producing a lot of reports of their observations in very good journals.

So all that having been said, most people judge the Harvard Nurses’ Study as having been quite informative and quite useful; that is the way that the New York Times described it, for example. However, I have a pretty serious criticism of the Harvard Study and that is due to the fact that virtually all of these nurses are still consuming a diet that is rich in animal protein. And it’s true that some of those nurses were able to decrease their fat intake quite substantially, down to maybe 15-20% of total calories compared to others who were up to 55-60%. That is a big change.

It turns out that when these nurses are decreasing their fat intake they’re actually increasing their already high intake of animal protein. The reason that this happens is that they were advised over the years to use lean cuts of meat to decrease fat intake, to use low fat milk products to decrease their fat intake. Well, the lean cuts of meat and the dairy, skim milk included of course, are foods very high in animal protein and have become even higher as a concentration. So these nurses as they assume they’re doing good things—they decrease their fat intake, but are swapping that so-called benefit, if there is a benefit there, to something that could be even worse. They don’t see any change in breast cancer rates. In fact if anything the rates tend to go up as the nurses decrease their fat intake. One thing you will see when we study a group of subjects all of whom are doing in general the wrong thing—namely consuming a western diet—is that researchers will just tinker with one thing at a time, like changing the fat intake, or changing this or changing that. This way the ability to be able to study the diet in a consistent comprehensive way is lost. In the results that they get, just on the basis of statistical probabilities, they might see small changes here or there that might otherwise be beneficial but it’s hard to detect them in that kind of milieu, which leads to a lot of confusing results. In other words, the Nurses’ Health Study does not have the kind of people that they really need: people who are consuming a total plant based diet, low in fat. Because of this, the researchers can’t conjecture and conclude and make comments about what the diet does or doesn’t do with any degree of authority because they don’t have the subjects in there that are likely to be the best responders. It’s not just the Nurses’ Health Study but it’s also most other case-controlled studies that have been done, because most of the case-controlled studies have been done on western subjects—sort of like comparing people who smoke four packs of cigarettes a day with somebody smoking three packs of cigarettes a day. Sometimes, yeah, you drop smoking from four packs to three packs in general, overall, you might see a bit of benefit, you might see it from time to time but, overall you probably see a lot of confusing results; some studies won’t show any effect. We have just minimized the ability to detect the kinds of effects that really are important.

S.J.: Is the natural growth hormone that is intended to help calves get big and strong, the natural growth hormone in milk products, still there in low fat products?

T.C.C.: Yes.

S.J.: So it’s the type of molecule that gets retained along with the proteins in the milk products.

T.C.C.: Right and that is generally true, but a more important thing that you have to think about that is that the amount of hormone activity we have in the body is often times not related to how much we’re actually consuming but rather it’s related to how much we’re actually synthesizing in our own body. If we consume a diet that continues to have high animal protein in it, and theoretically, you move to a diet low in fat, even a little higher in protein, let’s assume for the moment that there will be less hormones being consumed. Well, that is a small amount and probably not terribly significant because the most important thing is the quantity of hormones being synthesized in the body, so-called endogenous hormone synthesis. Going to these low-fat-high-animal-protein-lean cuts of meat kind of diet, if anything, will just continue to stimulate hormone production in the wrong direction.

S.J.: So the abundant growth factor in milk products doesn’t make them more problematic?

T.C.C.: Yes, on balance I think that we have to agree that there is some possibility this could be a problem. I think you are probably talking about bovine growth hormone for example in cow’s milk. That has become commonly used in recent years.

S.J.: It doesn’t have to be added; it’s naturally there?

T.C.C.: Yes, as far as structures are concerned, that kind of hormone is virtually chemically identical to the human growth hormone, and as we know, this could be a problem. We’re absorbing it and, in turn, the amount in our bodies could increase. If you look at the proportion of the total growth hormone level that we have in our body compared to the amount that we’re actually consuming, it’s a relatively minor contribution compared to the amount we synthesize. It’s an important question because some people will argue that the bovine growth hormone in cow’s milk is chiefly responsible for the hormone-like effects that milk produces. I think it’s a mistake to make that argument, because not only does the data not support it, but when people make that kind of argument then the scientific community and the regulatory community, in particular, can quickly point to alternative studies that show that and they say ‘we don’t see all these bad effects with this little increase in this,’ and they can get away with it. It’s an argument that unfortunately is a diversion from something that is more important. But having said all that I have to say that for this and other reasons, I think that giving cows bovine growth hormone has nothing to do with health and has everything to do just stimulating milk production in those cows. It’s ridiculous to say it can be beneficial to humans, and for the regulatory agencies to argue that there is no effect only because they don’t see any obvious effect based on assuming a relationship between the amounts being consumed. If we enrich the conversation and look at all the effects that can occur, then you can take away from some of the FDA’s favorite arguments.

S.J.: So the protein stimulates our own production of growth hormone?

T.C.C.: Right, it does.

S.J.: And that’s really at least as important as the dietary growth hormone [intake?]

T.C.C.: Yes, much more important even. I think that saying bovine growth hormone-laced cow’s milk is no particular problem is a false conclusion, even if the data doesn’t specifically exist to support the alternative argument, it’s only dealing with part of the overall effect. I think that it’s one way that regulators get around the argument.

S.J.: Steroid rings are very hard to break down in a pasteurization process.

T.C.C.: Exactly, and I don’t think that that kind of heat process is going to destroy the steroid, that is my guess, but I don’t know the numbers.

S.J.: I have read that during homogenization, macro-globules of fat are produced and various substances can survive better protected in those macro-globules of fat, maybe in pasteurization and in our digestive acids.

T.C.C.: Sure, I think that’s entirely reasonable.

S.J.: Okay, seems plausible at any rate.

T.C.C.: Yeah.

S.J.: Colostrum, the milk produced in the first few days post-partum, contains much more growth factor and protein than regular milk. We’re saying that the protein is at least as problematic as the growth factor, growth hormone. According to the Physician’s Desk Reference there is no credible evidence to support claims that bovine colostrum burns fat or builds muscle. Do you agree?

T.C.C.: Gosh, I don’t know that. It has always been argued that colostrum’s real value has been primarily from the standpoint of passing on immunity into the young. All farmers know that calves need to have that colostrum for 2 or 3 days as a passive immunity kind of phenomenon. Colostrum is enriched in the protein based antibodies that the mothers produce. Whether the colostrum has so much more protein and growth hormone, I don’t know.

S.J.: Would the antibodies do people any good? The bovine antibodies?

T.C.C.: My first guess is no, I don’t think so. Because the antibodies are so specific it’s possible in this particular case if they’re created to resist certain kinds of organisms and a human consumes it, we could also get some benefits, I suppose.

S.J.: But it has to be recognized by the human immune system as signaling, even if they did attach to the antigen, and then the immune system would have to act on that signal, so the immune system would have to be quite analogous in detailed molecular ways, to the bovine immune system. So maybe it would be more of a coincidental effect, just the way bovine growth hormone is coincidentally identical to human growth hormone. Probably not many people have studied this issue anyway, but what I was getting at is a lot of people supplement colostrum, to build muscle.

T.C.C.: I didn’t know they were doing that. Are they doing that a lot now?

S.J.: Some people do. I said a lot of people but I really don’t know how many.

T.C.C.: Wow.

S.J.: People also started supplementing whey protein.

T.C.C.: I was going to say the same thing. I mean I have looked at the websites for companies that produce whey and boy, talk about a snake oil salesman. Those people are advertising whey as the greatest nutritional discovery of all time.

S.J.: Is it possible that whey would have the same effects in promoting diseases as casein?

T.C.C.: Yes, definitely.

S.J.: Any animal protein.

T.C.C.: Right, they’re just really, really stretching the truth. Those claims are just outrageous.

S.J.: By what mechanism does exposure to high levels of the hormone estrogen over long periods greatly increase rates of cancer in the reproductive system?

T.C.C.: Well, in this case again, estrogen is acting rather like a growth hormone—it comes to the cell, goes to the nucleus, turns on things. It does a whole host of things. And incidentally, there are dozens of different kinds of estrogens, but the one that is most often studied is called estradiol. I think it’s very similar to growth hormone in general, to the extent of my knowledge. These hormones bind to receptor proteins intracellularly, and are carried to the nucleus and turn on all kinds of enzymes and other kinds of things which are then, in turn, being synthesized by the genes.

I think the evidence that you are probably referring to is the association between estrogen levels in women and risk of breast cancer. The China Study was really pretty informative on this point, which was very exciting. We compared using the same methodology, even the same analysts, the same laboratory, so we didn’t have to worry about methodology problems. We compared rural Chinese women with British women living on Guernsey Island, who were consuming typical western diets and who had much higher breast cancer rates. And it turns out that the level of estrogen in the British women, western women, was about 50% higher than that of the rural Chinese women. We also found that the age of menarche for western women is somewhere around 11 or 12 years, and the age of menopause to be about 52 years. In contrast, for the rural Chinese woman, age of menarche on average was about 17 years and age. The age of menopause was around 48 years. In effect, the western woman has about 8 or 9 extra years of reproductive life. This is a time in which the estrogen levels in the blood are about 50% higher. Do the calculation; the area under the curve kind of thing. You integrate concentration and time and it turns out the estrogen levels [exposure?] in western women are about 4 to 5 times higher than in a rural Chinese woman who is incidentally consuming a plant based diet. And that is just about the exact same difference you can see in average risk of breast cancer. To take the next step you can ask, well what relationship is there between breast cancer and estrogen level? I think that was your original question. There is a lot of evidence now showing that having a high exposure to estrogen over a prolonged period of time, for many years, in the case of western women can perhaps have a very direct effect on causing breast cancer; it’s not a good idea. Most likely it’s a combination of the estrogen acting directly on latent cancer cells to cause them to grow faster as well as to do other more indirect kinds of things. While it was very interesting that we got this really tight coupling of estrogen levels over all with breast cancer rates in western women, and the group that we were working with at the time was headed up by a man by the name of Malcolm Pike, professor Malcolm Pike who was a professor of medicine at the University of Oxford. Now he’s at the University of Southern California. He’s really a brilliant fellow who is acknowledged as probably the world’s leading expert on estrogen activity. It was his lab that actually did the analysis for us, along with a fellow who is now also becoming very prominent by the name of Timothy Key at the University of Oxford. According to Malcolm Pike, this relationship between estrogen and breast cancer is, in his mind, confirmed. You see western women having much higher rates of breast cancer—they start their periods earlier in life, they end up with higher estrogen levels. All this is occurring because of the kinds of foods they’re consuming. Animal protein will increase growth rate which in turn, turns on the menstrual cycle earlier in life. The animal protein itself will then increase estrogen synthesis, even during an adult woman’s life. There is so much evidence all converging now, so much evidence.

S.J.: What tissues and glands produce estrogen?

T.C.C.: Well fatty tissue does, of course, and adipose tissue does. Also, again as I said, there are so many different kinds of estrogens. The adrenal glands are obviously a kind of factory for steroid-like material, and I think some other tissues may as well, although I just can’t tell you exactly. I think liver synthesizes some estrogen, I’m not sure there either.

S.J.: So being composed of fatty tissues, the breast is particularly at risk?

T.C.C.: And so overweight women have more adipose tissue and produce more estrogen. That could be the link between being overweight and breast cancer.

S.J.: What foods stimulate our production of estrogen?

T.C.C.: Cow’s milk is probably the best example. Animal foods do for sure.

S.J.: Why would cow’s protein, milk protein in general, stimulate estrogen production more than other types of animal products?

T.C.C.: Well, I don’t know how much difference there is. But to go back to the question we had before, milk is constructed, and if we can think teleologically, it’s constructed as food early in life to create a growth kind of environment, which includes growth hormones, estrogens and so forth. That was the purpose of this kind of food.

Cow’s milk is now being shown, among its many adverse effects, as being related to things like prostate cancer, uterine cancer, and breast cancer: all cancers of the reproductive tract. This is not surprising because cow’s milk is a fluid that is part of the reproductive cycle. In the cow, the milk is a reproductive component. It’s produced by a reproductive system, in the mother cow, and is used to support the very young when they’re first born. We, then, as a species consume the stuff for the rest of our lives.

S.J.: Would yogurt also be a problem?

T.C.C.: I have often said that I don’t think so. Or if there is a problem there it’s probably much less.

S.J.: … they do to the protein mainly, rather than...

T.C.C.: Well, yogurt is interesting. It heard once a presentation by a fairly noted guy, I think he did his science quite well, who reviewed the evidence on yogurt and presented a lot of information to show that yogurt has some real health benefits. At that time he wasn’t taking note of some of the adverse effects that we also know about, so it was kind of hard to sort it out. I was pretty convinced that yogurt is obviously a different product from fresh cow’s milk. It’s a fermented product and the fermentation process is producing a lot of metabolites that are antioxidant in nature and so forth. That almost makes it in a sense a little bit like a plant; at least it’s taking a step in that direction. Also, the protein of yogurt is being broken down to a great extent, and when you get a break down of protein, you get a synthesis of new antioxidants. It’s not surprising, maybe, that you can find yogurt to be, on some occasions, certainly less offensive than milk.

S.J.: Do you know of any studies that have been done?

TTC: No, not on yogurt, let’s say, and breast cancer.

S.J.: So of all the animal products, yogurt might be one…

T.C.C.: Yeah it’s one that…

S.J.: Would you recommend it for people?

T.C.C.: No, I wouldn’t go so far as to recommend it, but I think I can say with some confidence that if there is an exception to all animal foods, I would list yogurt as a potential exception. I would also list cold-water fish as a possible exception, although you’ve got lots of problems there to have to think about, the dioxin and the mercury that gets in the fish.

S.J.: Dioxin?

T.C.C.: Yeah.

S.J.: That is also hard to break down because of the rings?

T.C.C.: Exactly, it just doesn’t…

S.J.: It’s a poison not a steroid.

T.C.C.: Absolutely. It’s a really noxious poison and it’s persistent in the environment because nature hasn’t learned how to deal with it. It’s a halogenated compound…

S.J.: Made by people.

T.C.C.: Made by people.

S.J.: So we have no defenses what so ever.

T.C.C.: Absolutely.

S.J.: And it builds up in every animal.

T.C.C.: Correct.

S.J.: So if we go eating products that include dioxin that has been filtered from the environment to a level that may be thousands of times greater, many thousands of times greater than in environment, and we store that poison then that could result in a problem. It would be a challenge, like any other challenge to the body that we’re also promoting diseases by our diet.

T.C.C.: Right. I think it’s a little bit weak, but there is some experimental evidence to suggest dioxin can act like a promoter of tumor development. So it gets classified as a carcinogen by the EPA for example.

S.J.: Wouldn’t yogurt, I mean it’s silly to talk about yogurt so much, but people do eat it for the beneficial bacteria that work in the intestines to improve digestion and stimulate even the blood vessel growth in the intestinal walls. So wouldn’t yogurt also have higher pesticides in it?

T.C.C.: It should.

[Note from S.J.: As does any animal-based food, even organic yogurt contains more concentrated PCBs and dioxin than in plants. For anyone with health challenges, a precautionary approach would be to avoid all animal-based foods, especially milk products. For those without health challenges, the safest diet is still the strictly plant-based.

BTW, the company Wildwood makes superb organic unsweetened soy yogurt (“Pleasantly Plain Soyogurt”), advertised as containing active probiotic beneficial bacteria. I like it better than any yogurt I’ve ever tasted, including dairy in bygone years, without any of dairy yogurt’s bitter aftertaste. Soyogurt is thick, smooth, with an agreeable mildly sour flavor, as a yogurt should have, due to the lactic acid produced during effective fermentation by probiotics. It works beautifully as sour “cream”. Since it contains active probiotics, it can take the place of dairy yogurt. As always with items I mention, I have no business association with the supplier, in this case Wildwood.]

S.J.: But the cold water fish with omega-3 fatty acids for example, would have some compensatory benefits for the body.

T.C.C.: Right, exactly.

S.J.: Is that why you said maybe yogurt would be one of the less problematic foods because it has some compensatory effects and maybe the cold water fish also has some benefits although a person could get omega-3 fatty acids by supplementing a DHA, which is one of those acids, sourced from algae.

T.C.C.: Sure.

S.J.: Which would have much less poison in it because algae are just plants. [My error re. plants: Algae belong to a different kingdom from plants, evolved earlier.]

T.C.C.: Or flax seed and soy beans. They all have some omega-3s.

S.J.: Then the body has to make the long chain omega-3s from the shorter chain omega 3s.

T.C.C.: Right

S.J.: But the advantage of DHA is that is already a long chain omega-3. For people who have decreased ability to make that, it’s good to take a supplement. That is why a lot of people might need to either eat fish or take a supplement. Whether from fish oil or sourced from algae depending on how safe you want to make your diet.

T.C.C.: Right

S.J.: Do phytoestrogens like those from soybeans cause problems?

T.C.C.: I have been asked that question many times and I have been meaning to go back and get up to date a little bit more on the literature. But from what I have seen so far, the phytoestrogens and their effects are a function of dose, just like so many other things. Unfortunately the discussion of phytoestrogens in the public literature is really very superficial; they don’t take that into consideration. Because phytoestrogens in soy beans at certain doses, the lower doses, can really act as anti-estrogens, consuming them at the lower levels can actually block either the effects of the estrogen we’re otherwise producing or the estrogen we’re consuming. In that sense they’re beneficial. There is a whole school of thought based around the fact that the phytoestrogens are a good thing not a bad thing, but then there were some studies that came along that showed that phytoestrogens at high levels could have estrogen-like activity, which is why they’re called estrogens. And it could lead to some adverse reactions. But then that begs the question: what kind of levels are they talking about? Very high levels, so it’s a dose-response relationship that has to be taken into consideration to decide whether the phytoestrogens are good or bad. It depends on how much we’re actually consuming, I think. I sure wouldn’t want to take phytoestrogens in pill form.

S.J.: Concentrated.

T.C.C.: Yeah, concentrated pill form I don’t think that is wise. Also I don’t think that is wise to over consume soy products. In this country, we have so many soy products in so many different things these days. I can imagine, although we don’t have the data yet, that all that excess soy, especially soy protein, maybe somewhat problematic. So my own position on this is, given first off my inadequate knowledge of the field, that I don’t have enough knowledge about the details of this. It’s also, I think, based on common sense. When we over consume things we get into problems, that is sort of a given. And as far as the amount of soy that some people are consuming these days, it’s 10 to 15 times higher than countries like China, where soy has been a native food for centuries. They didn’t consume it that way. So I don’t know the answer to the question. I think that consumed in reasonable amounts, soy is a very good food. I think edamame are very delicious, first off, and now we know about the omega-3s, they have got to be a good food, just like peas and beans and many other things. It’s just that we mash it all up and make all these other products, and eat it in about 50 different ways everyday, with extra salt and fat added sometimes.

S.J.: It’s no longer health food.

T.C.C.: Yeah, I think we’re getting out of the territory of health food when we’re doing that.

S.J.: Again what foods are probably causative with premature puberty? We have an epidemic of premature puberty in the industrialized world.

T.C.C.: That is certainly true and dairy certainly is a major factor. And we’re consuming dairy in so many different ways these days. But we’re also consuming in this country a diet that is, on average, very rich in animal foods. It’s as rich in animals as it has ever been, and it has gradually become richer, which is also a factor. There are then other factors, like estrogen disruptors, which seem to be spreading all over the world. In this case we’re talking about dioxin and other related compounds like that. There is some pretty good evidence showing that exposure to these halogenated chemicals in the environment and various and sundry places do cause problems at least in wildlife. They do, in the laboratory, cause pretty serious problems with the reproductive system, so that you can see birth defects and sperm count in men supposedly decreased by 50% world wide. The rate of decline world wide, according to a book that I read not too long ago, would suggest that in about another 30 to 50 years, men will have no function. So then what is the human race going to become?

S.J.: I’ll ask about impotence later.