The Downside of Bacon

Processed meats linked to raised colorectal cancer risk, says World Health Organization group


Bacon may have a great reputation on the Internet, but its reputation in the health community just took a nosedive.

Bacon and other processed meats like ham and sausage may be linked to an increased risk of colorectal cancer, according to an agency within the World Health Organization (WHO).

The WHO's International Agency for Research on Cancer (IARC) also said that unprocessed meats like steak "probably" cause cancer.

These findings, announced this morning and detailed in The Lancet Oncology, have already received criticism from players in the meat industry, reports Reuters. But the group of 22 scientists with the IARC didn't just call out meat with no evidence. These researchers looked at 800 past studies on meat and cancer risk at a meeting in Lyon, France, earlier in October.

“On the basis of the large amount of data and the consistent associations of colorectal cancer with consumption of processed meat across studies in different populations, which make chance, bias, and confounding unlikely as explanations, a majority of the Working Group concluded that there is sufficient evidence in human beings for the carcinogenicity of the consumption of processed meat,” according to the IARC report.

Representatives of the meat industry have pointed out that some of the past studies on which the IARC based its conclusions may not have accounted for factors other than diet in cancer risk, such as smoking or lack of exercise.

“Cancer is a serious disease that we don’t want to take lightly, but correlation is not causation,” said Dr. Shalene McNeill, director of human nutrition at the National Cattlemen's Beef Association, per The Wall Street Journal. Dr. McNeill attended the IARC meeting that produced these recent findings.

After finding that eating around 50 grams of processed meats — less than two slices of bacon, according to BBC News — could raise your colorectal cancer risk by 18 percent, the IARC gave bacon and its processed counterparts the highest cancer-causing indication, right alongside tobacco and plutonium. Still, experts are saying that a little processed meat from time to time isn't likely to cause much harm.

"For an individual, the risk of developing colorectal (bowel) cancer because of their consumption of processed meat remains small, but this risk increases with the amount of meat consumed," said Dr. Kurt Straif, head of the IARC Monographs Programme, in a press release.

The IARC also said that unprocessed red meats "probably" cause cancer. According to The Wall Street Journal, the "probably" carcinogenic group also includes a well-known herbicide called glyphosate.

Red meat is a good source of vitamin B-12, iron and zinc, according to BBC News.

IARC estimates held that around 34,000 cancer deaths worldwide each year could be attributed to processed meat, BBC News reports. While those are serious numbers, the BBC also pointed out that 1 million cancer deaths are attributed to smoking each year, and 600,000 are likely due to alcohol.

As the dust settles around the processed meat debate, some health experts are encouraging moderation above all.

"People should limit consumption of red meat and avoid consuming processed meat, but they should also have a diet rich in fiber from fruit and vegetables and maintain an adequate body weight throughout life and limit the consumption of alcohol and be physically active," said Dr. Teresa Norat, one of the advisers on the IARC report, per BBC News.