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According to the World Health Organization, up to 40 percent of all cancers are preventable, and the American Cancer Society reports that one-third of all cancer deaths in the United States can be attributed to nutritional factors.

A vegan diet maximizes the intake of foods that help us fight cancer—fiber-packed grains and beans and phytochemical-packed fruits and vegetables—and eliminates the foods that promote cancer. According to the Physicians Committee for Responsible Medicine, this means that vegetarians “are about 40 percent less likely to get cancer than nonvegetarians, regardless of other risks such as smoking, body size, and socioeconomic status.”

A vast array of studies from top universities and independent researchers has found that eating the flesh of chickens, cows, and other animals promotes cancer. Here are a few:

  • One study compared cancer rates of vegetarians and meat-eaters in 34,000 Americans. The results showed that those who avoided meat, fish, and poultry had dramatically lower rates of prostate, ovarian, and colon cancer compared to meat-eaters.
  • An 11-year-long German study involving more than 800 vegetarian men found that their cancer rates were less than half those of the general public. The lowest cancer rates were found in those who had avoided meat for 20 years or more.
  • A 2007 study of more than 35,000 women published in the British Journal of Cancer found that women who ate the most meat had the highest risk of breast cancer.
  • A study comparing the dietary habits of men in 32 countries found that the highest risk factors for prostate cancer mortality were meat and dairy products. By contrast, another study of men diagnosed with prostate cancer showed that a diet rich in fruits, vegetables, and grains can slow or even halt the progression of the disease.
  • Scientists from the Bremen Institute for Prevention, Research, and Social Medicine and the German Cancer Research Center observed in the American Journal of Clinical Nutrition that “the relationship between a vegetarian and fiber-rich diet and a decreased risk for colon cancer has been reported in many studies.”

Dr. T. Colin Campbell, arguably the foremost epidemiological researcher alive today, believes that animal proteins are the prime carcinogen in meat and dairy products. He points out that “human studies also support this carcinogenic effect of animal protein, even at usual levels of consumption. … No chemical carcinogen is nearly so important in causing human cancer as animal protein.”

Fat is a culprit, too: Higher-fat diets raise estrogen levels, whereas plant-based diets tend to keep them at a safe level, which doesn’t promote the growth of cancer cells. But fiber—a nutrient plentiful in vegetarian diets—can help our bodies eliminate excess estrogen, cutting the risk of cancer.

It seems that with every bite of meat, we increase our risk of cancer. Luckily, we can eliminate animal products from our diets and replace them with vegetable proteins that protect our health instead of harming it.

Order PETA’s free “Vegetarian/Vegan Starter Kit” and start on the path to a healthier you today.