High-fat, high-protein diets may increase the risk for colon cancer, a new study suggests. Photo by Derneuemann/
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Nov. 12 (UPI) -- Diets that adversely affect the health of the gut microbiome -- the bacteria in the digestive tract that helps the body process food -- may increase the risk for colon cancer, a study published Friday by JAMA Network Open found.
Heavy consumption of red meat, processed meat and products such as french fries and soft drinks, coupled with a low intake of fruits, vegetables and whole grains, raises the the likelihood a person will develop colon and rectal cancer by 27%, the data showed.
Red and processed meats and other foods high in fat and protein, which contain dietary sulfurs, boost production of gut bacteria to metabolize them, or convert them into energy for the body.
These metabolites, which become part of the gut microbiome, can increase inflammation, cause damage to the body's DNA and raise the risk for growth of colon and rectal tumors.
"There have been studies that have shown that diet and what you eat can increase your risk for colorectal cancer," study co-author Dr. Andrew T. Chan told UPI in a phone interview.
"What we've learned is the reason why these foods may increase a person's risk for colorectal cancer is because of the effects they have on the gut microbiome," said Chan, a gastroenterologist at Massachusetts General Hospital in Boston.
More than 140,000 people in the United States are diagnosed annually with colorectal cancers, or tumors in the colon or rectum, and about 50,000 die from the diseases each year, according to the Centers for Disease Control and Prevention.
Obesity, or being severely overweight, appears to increase a person's risk for these cancers, while consumption of foods rich in fiber and other nutrients may lower it, research suggests.
For this study, Chan and his colleagues analyzed data on more than 210,000 adults, about 3,200 of whom developed colorectal cancer.
In about 500 participants, just over 300 of whom were men, they tested the effects of what they called the sulfur microbial diet, which consisted of eating a lot of low-calorie beverages, french fries, red meats and processed meats.
Participants on this diet also ate lower amounts of fruits, yellow vegetables, whole grains, legumes, leafy vegetables and cruciferous vegetables, the researchers said.
The dietary content of the participants was monitored using a food-frequency questionnaire.
After genetic profiling of these participants' gut bacteria, the researchers identified 43 sulfur-metabolizing bacteria.
The presence of these sulfur-metabolizing bacteria was associated with an increased risk for colorectal cancers in these participants, the data showed.
"These findings suggest that diets can be used to modify the gut bacteria to potentially reduce the risk for these cancers," said Chan, who also is a professor of medicine at Harvard Medical School.
