Avoiding red and processed meats could cut your cancer risk, according to American Cancer Society guidelines

• New guidelines from the American Cancer Society recommend limiting red meat and avoiding processed meat whenever possible to reduce one's risk of cancer.
• Evidence has linked red and processed meat to higher risk of many types of cancer as well as a higher chance of dying from cancer.
• Some researchers have questioned the link between meat and cancer risk, but epidemiological data continues to show an association between meat and colorectal cancer, breast cancer, and prostate cancer.

It's no secret that a juicy burger or a ballpark hot dog isn't great for your health.

Red meats — like beef, pork, veal, lamb, mutton, and goat — have long been linked to health risks including cardiovascular illness.

Processed meats are even more dubious for health, with a large body of research linking higher risk of mortality and chronic illnesses to eating too much of anything that's been cured, smoked, or salted. That includes bacon, sausage, ham, hot dogs, and deli meats.

They should be taken seriously as a cancer risk, too, according to new cancer-prevention guidelines from the American Cancer Society, which take a stronger stand against red and processed meat than ever before.

Previously, the guidelines suggested limiting meat consumption as part of an overall healthy eating pattern. But the latest recommendations advise against it as much as possible, based on growing evidence that consistently links meat-eating with some of the most common types of cancer worldwide, including colorectal cancer, breast cancer, and prostate cancer.

Some research linking meat to cancer risk has been controversial

A 2019 meta-analysis found that lowering intake of red and processed meat was associated with a lower risk of cancer death, and eating less processed meat in particular was linked to lower risk of colorectal, esophageal, and breast cancers.

These findings are controversial, however. The authors of that study ultimately concluded the effect of eating meat was small, and the evidence linking it to cancer risk was uncertain.

The controversy stems from the type of evidence used in evaluating diet and disease risks.

The gold standard for evaluating drugs, the randomized control trial, is difficult to apply to nutrition in this respect. That's because it would be logistically challenging, and possibly unethical, to assign two separate groups to a dietary plan at random and get them to adhere to it for a long period of time to see whether one group ended up with more cases of cancer.

The evidence overwhelmingly supports limiting red and processed meat, the ACS says

The ACS guidelines, however, cite extensive evidence linking red meat, and processed meat in particular, to health risks.

One such study from 2009 found that nitrates in processed meats, and heme iron in red meat generally, might cause oxidative damage to DNA. Other, much older research has found that cooking meat on high heat or over open flame appears to produce carcinogens, or cancer-causing compounds.

And a 2015 review of 800 epidemiological studies consistently linked meat with higher risk of cancer, particularly colorectal cancer, leading the researchers to define processed meat as carcinogenic and red meat as "probably carcinogenic to humans."

The strongest evidence links meat consumption with colorectal cancer, the third-most-common type of cancer worldwide. Research has found that relative risk of colorectal cancer increases by 22% with each additional daily serving of red meat and 23% with each additional daily serving of processed meat, according to the ACS.

There's still more research to be done, the new guidelines acknowledge. But based on what we know now, the ACS strongly suggests swapping out that steak dinner with chicken, fish, or even plant protein.

"There is no one food or even food group that is adequate to achieve a significant reduction in cancer risk," Dr. Laura Makaroff, the American Cancer Society's senior vice president of prevention and early detection, said in a statement. "People eat whole foods — not nutrients — and evidence continues to suggest that it is healthy dietary patterns that are associated with reduced risk for cancer, especially colorectal and breast cancer."

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