CANCER CONCERNS? What the Science Says


by Dakota Decker

Do you have cancer concerns? Most of us are at least a little concerned about cancer. After all, cancer is the second leading cause of death in Western nations. Approximately 40-percent of men and women in the US and the UK will be diagnosed with cancer at some point during their lifetimes (based on 2010-2012 data from the National Cancer Institute in the US and Cancer Research UK). The good news is that studies have shown the risk for vegetarians to be about 12-percent lower than that, and it is presumed to be even lower for vegans. (1)

It is now accepted theory that half of all cancer cases worldwide are potentially preventable. Thus, more studies are being published on cancer as it relates to dietary choices. The Loma Linda Center in California has done numerous long-term studies on Seventh-Day Adventists showing the benefits of the vegetarian diet, but studies on the vegan diet have been hard to find. One of the first is a recent study that looked more closely at the data in the Adventist Health Studies and the diets of the 69,120 people studied. When vegans were separated out from other vegetarians by researchers, the results showed the largest statistically significant reductions in overall cancer rates among vegans. In fact, the study states, “When analyzing the association of dietary patterns with overall cancer risk, only vegan diets showed a statistically protective association when both sexes were combined.” (2)

This study is especially important since previous studies have lumped vegans in with other vegetarians (when that 12-percent decrease in cancer risk was determined). For instance, in the Oxford Vegetarian Study and the European Prospective Investigation into Cancer and Nutrition-Oxford (EPIC-Oxford) studies, vegans were not considered as a separate group because their incidents of cancer were so rare. Other reviews of past Adventist data have also failed to provide relevant data since the vegan population in the study was so small. (3)

There is clearly a need for more published studies on the reduced risks of diseases, including cancer, among large populations of vegans. In the meantime, some of the most reliable data we have comes from information on the specifics of the cancer-causing effects of animal product consumption and the anti-cancer attributes of fruits and vegetables. (4)

Let us begin with the largest nutritional study ever conducted, widely known as “The China Study.” Dr. T. Colin Campbell and his colleagues at Cornell and Oxford poured over twenty years of extensive data from surveys on the entire population of China (collected by the Premier of China, Zhou EnLa, when he was dying of cancer and wanted to determine a cause). It was ultimately determined that the people who ate a whole food plant-based diet had the lowest incidents of all diseases, including most cancers. (5) (The book on this sold over a million copies)

There are also myriad studies that show strong correlations between meat eating and cancer. (6) High consumption of vegetables and fruit were associated with decreased risk of breast cancer, while consumption of pork and chicken were associated with increased breast cancer risk in another study. (7) Cutting out meat reduces your risk of cancer, but “vegetarians,” you must be aware that the animal products you continue to ingest are also carcinogenic. Associations have been found between fatal cancer and the consumption of milk and cheese. (8, 9)

If you are not one of the over one-million people who have read The China Study, you might be interested to know that casein (the protein in milk—which is ultra-concentrated in cheese) was found to be highly carcinogenic. Since then, very few studies have been done on casein and its cancer-causing effects. We know that the dairy industry has a powerful lobby, so we are not surprised. However, there was a study published just last year where casein was observed in vitro with different types of cancer cells. It was found to promote the growth of cancer cells, specifically prostate cancer cells. (10)

All of the above is merely to say that eating vegan is the most cancer-preventive diet you can eat. But even as vegans, we are not 100-percent immune to cancer. In fact, a few prominent vegans have died from cancer recently, and this has many vegans (who previously thought their diets made them “bulletproof”) questioning how this could happen.

As mentioned above, vegans reduce their chances of having to deal with “the big C” as well as other diseases. I realize that I am largely preaching to the choir as I relay this information to readers of Vegan Health & Fitness Magazine. You are some of the most nutritionally-educated people in the world. You have to face questions, and often ridicule, from omnivores on a regular basis. Most of us vegans have read a few books and spent some time on the internet boning up on how to tell people where we get our protein, calcium and many other nutrients. You may have specifically researched how vegan foods conquer disease also.

For all you nutrition-science nerds and folks who would really like to avoid cancer, we hope to bring you new information here in this series of articles on cancer. As the safeguard of my own health, I appreciate it when information is shared on things that are theorized to be carcinogenic as early as possible in the research. I don’t want to wait until the first few groups of people have died of cancer (and perhaps be one of them) before I am aware of a possible risk. And I certainly do not want to wait until the industry fights back with their own skewed studies that attempt to prove that a product is not actually carcinogenic (as the tobacco industry did by producing studies that showed that smoking was good for you); and then, after years of litigation, the truth finally surfaces.

On the other hand, I would never suggest that something may be carcinogenic unless there were numerous peer-reviewed scientific studies published in respected journals that support the information. (Nor would my editor allow it). And, if that information could possibly save lives, even if that information is scary or unpopular, it seems irresponsible to not share it. So here we go.


Carageenan is used as a gelatinous thickener in many non dairy milks and vegan hot dogs (as well as meat and dairy products), It is derived from red seaweed, which sounds harmless enough; but often when we extract a substance from nature, it takes on a whole new manner of being (and reacting in the human body).

We do not condone the use/torture of animals in laboratories. Having said that, we would like to point out that when scientists want to create ulcers and, ultimately, colon and rectal cancer in an animal for experimentation, they routinely give the poor creature carrageenan. That is how reliably it induces cancer in animals. (11)

Of course, there are many examples of animal experimental results not applying to humans, and the ensuing harm that causes us all. So, we would not report this information to you without having human studies to rely upon. For instance, we reviewed the first study (which took place in 2006) where human intestinal cells were exposed to “food grade” carrageenan (not poligeenan). It was shown that this exposure (the average Westerner consumes about 67 times this amount in a day) triggers a distinct inflammatory pathway. As they put it in the study, it triggers “an inflammatory cascade… linked with development of lymphomas and mutations…[that] may provide a link between genetic and environmental causes of IBD [Inflammatory Bowel Disease].” (12)

Now the US FDA has been aware of concerns with carageenan since 1972 when it proposed limiting its usage. But, it never followed through and has never limited its use. In 1982 the International Agency for Research on Cancer stated that carageenan poses a cancer risk for humans. However, the only regulation we could find is that it is not permitted for use in infant formula in Europe (as per the decision by the European Parliament and Council in 1995); although it is approved for the same use in the US (by the Food and Drug Administration most in 2004).

Of course there are proponents of carageenan who claim that exposure to high-molecular weight (food grade) carrageenan is not harmful. They claim that only the low-molecular weight carageenan (recently given the name poligeenan) is harmful. Scientists who are experts in the field, such as Dr. Tobacman are skeptical and theorize that the rise in breast cancer in the past few years may be due to the rise in carageenan use in food products (13) Regarding controversial potential carcinogens, I prefer to err on the side of caution, as I mentioned earlier.

However, I do think there is plenty of good in the seaweed it is derived from, Chondrus crispus, also known as Irish Moss. It is frequently used as a gelling ingredient in many of the most progressive raw vegan restaurants today. However, carageenan is an extract from the moss and does not use the whole plant. Extractions and half-foods are often problematic. (For instance, white rice has the hull removed, which makes it very sugary and spikes insulin. And, wheat gluten is difficult for many people to digest as the germ of the wheat has been removed.) And speaking of extractions, on to our next cancer concern.


At first I thought that maybe the title of this section was a little harsh (although it’s got a nice ring to it thanks to the power of alliteration). But upon reflection, I think it’s actually perfect. I realize I’m stepping on some big toes here, but sometimes that’s what being a health-conscious, animal rights activist, environmentalist vegan is all about. I realize that people LOVE their vitamin pills. Supplements are thought of as “health insurance” in a bottle. The idea is that if you don’t get the nutrients you need from your food choices, no need to adjust your diet, just pop a pill and it will offer all the health benefits that actual whole food would offer. As funny as I find it that someone would think that popping candy-flavored chewable vitamin-C tabs (or what about the ones that are shaped like Fred Flintstone-- am I supposed to take those seriously?) would be just as nutritious as eating an orange or an apple or some kale, it is indeed the popular way of thinking.

Americans spend around $30 billion per year on supplements! We also live in an age when food manufacturers think that fortifying food products with all sorts of vitamins and minerals makes their product more “healthy.” Vegan milks, for instance, are usually fortified with vitamins D and B12. Energy drinks contain ridiculous amounts of B vitamins (because they have stimulant properties). Breakfast cereals contain copious amounts of all sorts of random vitamins and minerals, varying according to the whim of the various manufacturer. This is another good reason to eat mostly whole non-processed foods. Only nature knows how much of a given vitamin or mineral we need, and only nature knows how to provide it in a form that will benefit and not harm the body.

At best, the most reliable studies have found no benefits from isolating phytonutrients in supplemental form. They confirmed what many nature-lovers have known all along. You must eat them in whole form to get their benefits. (14, 15) Many supplements have also often been found to cause rather than prevent diseases. (16, 17)

Dr. T. Colin Campbell’s second book, Whole: Rethinking the Science of Nutrition, gives a thorough critique of the supplement industry. Many examples of supplements that were theorized to help a given problem, actually made it worse. He sites to three famous studies on vitamins that were thought to prevent cancer, that were found to promote rather than prevent cancer when taken in supplement form.

My biggest concern for VHF readers, however, is that supplementation with vitamin B12 (something many vegan experts claim that all vegans need to do) has been found to stimulate a three-fold risk of prostate cancer development. (18, 19, 20) In a study where heart disease patients were given B12 in the hope it would remedy their cardiac issues, the patients ended up receiving diagnosis of cancer on top of the heart disease, and having higher rates of death. (21) Another recent study in China where elevated B12 levels were associated with esophagus, stomach and liver cancer, ended with researchers express concern over food fortification. (22)

This is the one vitamin pill that most vegans think that they have to take (although you should know that none of our staff members take it, including those who have been vegan for decades). Some high-profile vegan doctors strongly recommend B12 supplementation for all vegans, although some maintain, in a less exuberant tone, that B12 supplementation is not necessary for vegans.

As always, I like to proceed with caution. While I choose not to take supplements, that may be too drastic for those who have fears of missing out on a vital nutrient. The push for taking supplements is strong, especially in the vegan and “health food” community. My biggest concern is regarding the astronomically high doses that many vegans are taking. Take a look at the foods that you eat that are fortified with vitamins and educate yourself on the recommended daily allowance (RDA) of vitamins. Chances are, you are getting more than the RDA already through fortified foods. If not, please do not exceed the RDA in your supplementation program.

This is part two of my ongoing report on cancer. As mentioned above, cancer is the second leading cause of death in developed countries (heart disease is number one). We were inspired to create this series, investigating cancer risks for vegans after several prominent vegans died of cancer. These deaths came as a shock to many in the vegan community who routinely hear about the myriad of scientific information on the cancer preventative benefits of the vegan diet.

It is true that vegans are in the lowest risk group of any dietary group (compared to omnivores and vegetarians). For more on that, please read the first study that specifically looked at the vegan diet (conducted by the American Association for Cancer Research) and found that “vegan diets showed statistically significant protection for overall cancer incidence.” Cancer Epidemiol Biomarkers Prev; 22(2); 286–94. ©2012 Or, you can take a look at tons of research that has been done on the cancer preventative benefits of eating vegetables and the cancer correlations with diets high in fat, especially animal fat. (See The Physician’s Committee for Responsible Medicine’s “Foods for Cancer Prevention” for a discussion on those studies.)

There are also myriad studies that show strong correlations (if not causative effects) of meat eating and cancer. (For instance, Chan, D. S., et al. “Red and processed meat and colorectal cancer incidence: meta-analysis of prospective studies.” PloS one 6.6 (2011): e20456.)

However, we vegans clearly are not bulletproof (or carcinogen-proof) or none of our sisters and brothers would have been lost to this illness. In the interest of reducing futher such losses, we are bringing you more information on avoiding cancer-causing stuff that vegans may encounter. As I stated in the last issue, this information is not meant to scare you. We are not into fear-mongering. We are into bringing you the cold, hard facts— fresh from the most respected scientific journals on the planet. Then you can decide for yourself how to proceed.


Researchers at five medical centers have reviewed studies and have reported in their meta-study that the worldwide increase in breast cancer is an effect of industrialization that has created an environment that bathes its inhabitants in a sea of estrogenic agents. Estrogenic compounds in pesticides and plastics mimic estrogens and also boost actual estrogen production in the body. Xenoestrogens are not produced in the body. Pesticides such as DDT, heptachlor, and atrazine, as well as several polycyclic aromatic hyrocarbons (PAHs), petroleum by-products and poluchlorinated biphenyls (PCBs) are known to induce or promote human mammary cancers. Raloff, Janet. “EcoCancers.” Science News (1993): 10-13.

This is one of the best reasons to eat all organic foods. Not only do you save yourself the pesticide residue, you also spare workers in the fields and other people and animals near the farms from high doses of these harmful chemicals that especially raise risks for breast cancers.

Another xenoestrogen is bisphenol-A or BPA. As you may have heard, this substance has been used to line almost every food container in the supermarket. Studies shouw that the natural estrogen 17β-estradiol and xenoestrogenic substances, like bisphenol A (BPA) are able to induce neoplastic transformation in human breast epithelial cells. Fernandez, Sandra Viviana, and Jose Russo. “Estrogen and xenoestrogens in breast cancer.” Toxicologic pathology 38.1 (2010): 110-122.

While we are seeing a lot of new containers with the words BPA-Free on the label thanks to the information about the harms caused by BPA reaching the public, it is still quite prevalent. A 2014 study states that BPA is one of the highest volume chemicals produced worldwide, with over 6 billion pounds produced and over 100 tons released into the atmosphere each year. Rezg, Raja, et al. “Bisphenol A and human chronic diseases: current evidences, possible mechanisms, and future perspectives.” Environment international 64 (2014): 83-90.

To date, multiple lines of evidence have indicated that BPA has estrogen-like activity and exhibits developmental toxicity in the reproductive organs and has inhibitory effects on testosterone synthesis. In vitro studies have revealed links between BPA exposure and hormone-related cancers, including breast, prostate, and ovarian cancers and endometrial carcinoma. Rezg, Raja, et al. “Bisphenol A and human chronic diseases: current evidences, possible mechanisms, and future perspectives.” Environment international 64 (2014): 83-90.

BPA can leach into food and beverages through the daily use of tin cans, baby bottles, reusable plastic water bottles, and polycarbonate plastic containers. The rate of BPA leaching increases when polycarbonate is scratched or discolored. Heat and non-neutral pH conditions (either acidic or basic) are two factors that influence BPA release, because hydrolysis of the ester bond linking BPA monomers occurs with changes in temperature and pH, such as those that take place when BPA-containing plastics are cleaned with harsh detergents or contain acidic or high-temperature liquids. My recommendation? Stick with glass containers.


This is the substance that is created on charred meat that has gotten a bit of media attention for its carcinogenic nature. However, most people are unaware that benzo(a)pyrene can also be found in plant foods and drinking water (although in smaller doses) when fields are contaminated by dirty air that contains particles of anything combusted in the area (coal, forest fires, smokehouses, burned farm crops, wood smoke from fireplaces, motor vehicle emissions, etc.). It is also present in the cooking flavoring “liquid smoke.”

Benzo(a)pyrene is a very potent carcinogenic PAH (polycyclic aromatic hydrocarbon) formed from heat and fire. It usually ends up on plant foods either from air pollution (soot in the air) or from cooking food at high temperatures until it is burnt or toasted. However the amount in the vegan diet tends to be quite low because vegan foods produce less of it. For instance, when heating starch from 370 to 390 degrees Celcius, 0.7 ppb benzo(a) pyrene was formed. This often occurs on the surface of bread during baking or toasting. (For comparison, cooking a steak yields up to 50 ppb.) Benzo(a)pyrene (BaP) TEACH Chemical Summary from the U.S. EPA, 8/1/2007.

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