Vegetarian Diets Help Prevent Cancer

By Michelle Fletcher, B.A.

Vegetarianism is more than just leaves and twigs. It’s also a far cry from the granola-munching we picture from the ’60s. Diverse in colors and flavors as it is in textures and nutrients, vegetarian diets also play a part in preventing and reducing the risk of cancer.

Before you munch on a salad or grab a stick of tofu (it’s much better cooked with some garlic or a little salt and pepper, by the way), hear the facts.

Formerly seen as strange and faddish, vegetarian diets are now recognized by many, including the American Dietetic Association as not only being nutritionally adequate, but also a healthful, natural way to treat chronic diseases. Cancer, heart disease, osteoporosis, diabetes, gallstones and many other chronic diseases are thwarted by integrating a healthful and well-balanced vegetarian diet.

Tufts University Medical School registered dietitian Johanna Dwyer summarized: “Data is strong that vegetarians are at lesser risk for obesity, atonic [reduced muscle tone] constipation, lung cancer, and alcoholism. Evidence is good that risks for hypertension, coronary heart disease, type II diabetes, and gallstones are lower.”

What is a vegetarian diet? In addition to copious amounts of fruits, vegetables, and grains, vegetarian diets also contain dry beans and lentils as protein sources. Many vegetarians also integrate low- to non-fat yogurts, milks, and cheeses, but this varies from vegetarian to vegetarian.

A number of studies point to the positive effects of vegetarian diets and health – most notably, cancer.

Scientific Research Supporting Vegetarianism in Cancer Prevention

Over 200 studies have revealed that a regular consumption of fruits and vegetables provides significant protection against cancer at many sites. People who consume higher amounts of fruits and vegetables have about one-half the risk of cancer, especially the epithelial cancers. The risk of most cancers was 20-50% lower in those with a high consumption of whole grains.

Further, the National Cancer Institute states that 35 percent of cancer deaths may be related to diet, according to its booklet: Diet, Nutrition, & Cancer Prevention: A Guide to Food Choices. “Diets high in fiber-rich foods may reduce cancers of the colon and rectum.  Reducing fat in the diet may reduce cancer risk and, in helping weight control, may reduce the risks of heart attack and stroke.”

An Italian study conducted at the University of L’Aquila in Teramo evaluated the relationship between diet and cancer development. By integrating a vegetarian diet, researchers concluded that the dietary changes could help prevent cancer: “A low use of fibers, the intake of red meat and an imbalance of Omega-3 and Omega-6 fats may contribute to increase the risk of cancer. On the other hand, the assumption of lots of fruit and vegetables may lower the risk of cancer. Protective elements in a cancer-preventive diet include selenium, folic acid, vitamin B12, vitamin D, chlorophyll and antioxidants such as carotenoids (alpha-carotene, beta-carotene, lycopene, lutein, cryptoxanthin). Ascorbic acid has limited benefits if taken orally, but is effective through intravenous injection. A supplementary use of oral digestive enzymes and probiotics is also an anticancer dietary measure. A diet drawn up according to the proposed guidelines could decrease the incidence of breast, colon-rectal, prostate and bronchogenic cancer.”

A 2006 study at the University of California, San Diego provided similar results. “These results provide preliminary evidence that adoption of a plant-based diet is possible to achieve as well as to maintain for several months in patients with recurrent prostate cancer. Adoption of a plant-based diet may have therapeutic potential in the management of [recurrent prostate cancer].”

Another study at the UCSD Cancer Center concluded that “Adopting a plant-based diet, along with stress reduction, may alleviate disease progression and have therapeutic potential for clinical management of recurrent prostate cancer.”

Further, the National Cancer Institute says that women who eat meat everyday are nearly four times more likely to get breast cancer than those who don’t. By contrast, women who consume at least one serving of vegetables a day reduce their risk of breast cancer by 20 percent to 30 percent, according to the Harvard Nurses Health Study. Studies done at the German Cancer Research Center in Heidelberg suggest that this is because vegetarians’ immune systems are more effective in killing off tumor cells than meat eaters’. Studies have also found that plant-based diets protect against colon, prostate, and skin cancers.

Former Surgeon General C. Everett Koop has said that 70 percent of all Americans are dying from diseases that are directly tied to their eating habits. By integrating a diet rich in fresh fruits, vegetables, whole grains and legumes will help you live longer, healthier, and take a big step in fighting chronic diseases.

Dietary Recommendations and Transition Tips

Here are some easy tips for making the switch:

  1. Eat an assortment of fruits and vegetables from all colors of the rainbow. That way, you are maximizing the variety of nutrients from these health powerhouse foods.
  2. Choose whole or unrefined grain products instead of refined products.
  3. Improve iron absorption by including a variety of beans, legumes, nuts and seeds – these are also excellent sources of protein.
  4. Don’t be scared of carbs! The American Dietetic Association recommends that your diet consist of 70% percent carbs – just make sure to make them fruits, vegetables, and whole grains.
  5. Minimize intake of less-nutritious foods like fast food and sweets. If the craving hits, indulge in a small piece of dark chocolate!
  6. To reduce cholesterol, limit eggs. Even for those not wrestling with cholesterol, limiting eggs is a safe bet. Try egg whites in omelets or substitute some tofu for an egg-free scramble in the skillet.
  7. Choose low- or non-fat varieties of dairy (this includes cheese and milk products). This will help reduce your risk for cancer, heart disease, and obesity. Try replacing milk on your cereal with almond milk or soy milk for added flavor sans animal fat.
  8. Consult a registered Dietitian when making the switch. This is especially important for pregnant or breastfeeding women.

Smile! You are taking a big step towards health, longevity, and a stockpile of delicious and easy recipes!

For more information on vegetarianism or for free vegetarian recipes, visit,, or

Michelle Fletcher is a freelance writer and practicing vegetarian that enjoys a good tofu scramble for breakfast.


Messina V, Burke K. Position of the American Dietetic Association: Vegetarian Diets. Journal of the American Dietetic Association 1997;97:1371-21.

Steinmetz K, Potter J. Vegetables, fruit, and cancer, I. Epidemiology. Cancer Causes Control 1991;2(suppl):325-57.

Jacobs DR, Marquart L, Slavin J, et al. Whole-grain intake and cancer: an expanded review and meta-analysis. Nutr Cancer 1998;30:85-96.

Divisi D, et al. Diet and cancer. Acta Biomed. 2006 Aug;77(2):118-23.

Nguyen JY, et al. Adoption of a plant-based diet by patients with recurrent prostate cancer. Integr Cancer Ther. 2006 Sep;5(3):214-23.

Saxe, GA, et al. Potential attenuation of disease progression in recurrent prostate cancer with plant-based diet and stress reduction. Integr Cancer Ther. 2006 Sep;5(3):206-13.

Dworkin, Norine. 22 Reasons to Go Vegetarian Right Now – benefits of vegetarian diet. Vegetarian Times. April 1999.

Dworkin, Norine.

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