The Link Between Cancer and a Meat-Based Diet

Cancer in all its forms is still a major killer in the United States, despite over thirty-five years of research and drugs aimed at treatment and prevention since President Nixon called for a war on cancer in 1972. A multitude of studies have suggested that the typical Western high-meat diet plays a big role in the development of cancer. And they don't just examine the role of red meat-beef, pork, lamb, and processed meat-but also poultry and fish.

For example, a recent major study by the American Cancer Society concluded that those on a high red-meat diet (defined as over 3 ounces a day for men and 2 ounces for women) had up to a 40% risk of developing colon cancer than those who were modest red meat eaters. And people who ate a lot of processed meat were 50% more likely to develop colon cancer and 20% more likely to develop rectal cancer than people who ate very little.

The researchers also determined that eating more fish and poultry rather than red meat lowered the colon cancer risk by 30% compared to those who did not eat those meats. Colon cancer kills over 56,000 people a year in the United States.

According to The Prostate Cancer Foundation, ongoing research is uncovering the negative role played by the fat in red meat, which can cause prostate cancer cells to grow. The fat that is proving to be particularly dangerous is ALA (alpha-linolenic acid), an omega-3 fatty acid abundant in animal and dairy products. In one study, it was found that men with high levels of ALA in their bloodstream were three times as likely to develop prostate cancer as those with undetectable levels of ALA. Another study indicated that men who ate a lot of meat were twice as likely to develop advanced prostate cancer. It was also found that consuming two other omega-3 fatty acids, DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid), found in fatty fish, was associated with a decreased risk of advanced prostate cancer. These beneficial fatty acids are also available in vegetable oils such as canola, walnut and flaxseed. Thirteen percent of the 240,000 American men who get prostate cancer every year will die of it.

Also, women who eat a lot of meat may be putting themselves at risk for developing breast cancer, according to a 2007 British study. In a recent University of South Carolina study, postmenopausal women who had consumed a lot of grilled, smoked or barbecued meat along with few fruits and veggies over their lives had a whopping 74% increased risk of developing breast cancer. Breast cancer kills 20% of women diagnosed with it.

What other factors could contribute to the link between meat and cancer? It is postulated that people who eat a lot of meat eat fewer plant-based foods, which contain fiber that helps fight cancer, as well as anti-cancer nutrients called phytochemicals. The fat in meat can raise estrogen levels, which can lead to cancer. The presence of fiber lowers them. Famed epidemiologist T. Colin Campbell believes that animal proteins themselves are carcinogens. The method of cooking meat can also contribute to developing cancer.

Carcinogens are created from grilling and frying meats at high temperatures. A substance known as PhIP produced through high-heat cooking has recently been added to the Department of Health and Human Services list of probable human carcinogens. Interestingly, in one study, the negative effects of PhIP were counteracted when participants ate cruciferous vegetables (like broccoli and Brussels sprouts) along with their steaks. Other possible carcinogens are the iron in meat and the salt, smoke residue, nitrate and nitrite preservatives in processed meat.

Can vegetarianism cut down on the cancer risk? The American Cancer Society study cited above unfortunately had no vegetarian participants, but numerous studies in Germany, Japan, and Sweden that have included vegetarians show that people who don't eat any meat, poultry, and fish have lower rates of colon, prostate, as well as ovarian cancer when compared to meat eaters. Ovarian cancer is the fifth most common cancer in women. The Physicians Committee for Responsible Medicine, a medical advocacy and research group, has stated that vegetarians have a 40% lower risk of getting cancer than meat eaters.

What can you do to minimize your chances of getting cancer as a result of your diet? The American Cancer Society recommends restricting red meat intake by keeping it small and lean; eating more poultry, fish, and beans; and baking, broiling, or poaching meat instead of frying or charbroiling it. The Prostate Cancer Foundation agrees that red meat intake should be limited. But if you really want to lower your cancer risk, the evidence suggests that a switch to a vegetarian diet may be your best bet.