Yogurt, a food loaded with live bacteria thought to contribute to a healthy gut microbiome, may also help protect against a particularly aggressive type of colorectal cancer, according to a recent study.
New research published this week found that regularly eating at least two servings of yogurt per week was tied to lower rates of proximal colorectal cancer (developing in the right side of the colon) that tested positive for the bacterial species Bifidobacterium. Bifidobacterium is a type of bacteria commonly found in yogurt that may have cancer-suppressing properties, according to study authors — but the exact mechanism behind these properties is still unclear.
“The takeaway message is that yogurt is good for your health,” says study coauthor Shuji Ogino, MD, PhD, the chief of molecular pathological epidemiology in the pathology department at Brigham and Women’s Hospital in Boston.
“The evidence is strong, as results are based on details about dietary intake from more than 130,000 people over 40 years,” Dr. Ogino says.
Certain Colorectal Cancers Are Especially Dangerous
Colorectal cancer has become a growing public health concern as rates among adults under the age of 50 have nearly doubled since the 1990s.
According to the World Health Organization, colorectal cancer is the third most common cancer worldwide and the second leading cause of cancer-related deaths worldwide.
Proximal (right-sided) colorectal cancer in particular leads to significantly worse outcomes compared to distal (left-sided) colorectal cancer.
A large study looking at cancer data from 13 U.S. states revealed that patients with proximal cancers were 13 percent less likely to survive at least five years compared with those with distal cancers.
A Healthier Gut May Help Fight Colorectal Cancer
For the analysis, Ogino and colleagues followed more than 132,000 health professionals over four decades. They collected dietary information, including details on yogurt intake, nearly every four years via questionnaire. Over the course of the study, the scientists identified 3,079 cases of colorectal cancer.
Overall, the study authors did not observe a significant link between regular yogurt consumption and colorectal cancer incidence. When looking at specific bacteria, however, they did find an association with yogurt consumption and Bifidobacterium-positive tumors. Information on Bifidobacterium content was available in 1,121 colorectal cancer cases — nearly one-third of which tested positive for the bacterium, while the remainder tested negative.
Those who ate two or more servings of yogurt a week were about 20 percent less likely to have Bifidobacterium-positive proximal colorectal cancer.
Ogino says that more research is needed to understand why this association exists, but the results suggested that yogurt may be linked to a protective effect by positively changing the gut microbiome (the ecosystem of microbes that live in your intestines).
“Yogurt may promote microbiome diversity, which may help improve immune function,” says Ogino, adding that a stronger immune system can help fight cancer.
While the study did not distinguish outcomes according to types of yogurt consumed, Ogino noted that plain yogurt was more likely to have a positive influence than products with sugar added.
The Link Between Diet and Cancer Risk
The findings contribute to a body of research illustrating the connection between diet, the gut microbiome, and the likelihood of developing colorectal cancer. An analysis of 16 previous studies looking at yogurt and cancer incidence concluded that increased yogurt consumption was related to lower colorectal cancer risk.
Another scientific investigation drawing on the same participant group as Ogino’s study found that eating one or more servings per week of yogurt compared with no yogurt consumption was connected to a lower incidence of proximal colon cancer.
“Multiple large studies have shown that yogurt can decrease the risk of colon cancer,” says Arun Swaminath, MD, chief of the gastroenterology division at Lenox Hill Hospital in New York City and a spokesperson for the American Gastroenterological Association. “This study goes a step further to show its relationship to a specific bacteria and tumor subtype.”
The results did not show that yogurt caused a lower rate of cancer, merely an association between yogurt consumption and a possible protective effect, notes Ogino. He also points out that the study was limited in that it was based on preexisting data, and not clinical trials that closely monitored patients, their habits, and food intake.
An Overall Healthy Diet May Lower Cancer Risk
Dr. Swaminath suggests that it would be helpful to see additional data on participant diet and lifestyle “People who eat lots of yogurt may have a healthier diet overall, and it’s not clear that it’s only the yogurt that has this effect,” he says. “Maybe people who eat yogurt frequently eat lots of fermented food that has been shown to be supportive of a more broad-based microbiome.”
He stresses that an active lifestyle, avoiding obesity, and eating a broad-based diet of unprocessed foods will serve almost everybody in decreasing their risk of developing colorectal cancer.
EDITORIAL SOURCES
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Resources
How Yogurt Supports Health Digestion. Mayo Clinic. November 29, 2023.
Ugai S et al. Long-Term Yogurt Intake and Colorectal Cancer Incidence Subclassified by Bifidobacterium Abundance in Tumor. Gut Microbes. February 12, 2025.
Sun J et al. Higher Yogurt Consumption Is Associated With Lower Risk of Colorectal Cancer: A Systematic Review and Meta-Analysis of Observational Studies. Frontiers in Nutrition. January 2022.
Michaels K et al. Yogurt Consumption and Colorectal Cancer Incidence and Mortality in the Nurses’ Health Study and the Health Professionals Follow-Up Study. The American Journal of Clinical Nutrition. December 2020.
Tom Gavin joined Everyday Health as copy chief in 2022 after a lengthy stint as a freelance copy editor. He has a bachelor's degree in psychology from College of the Holy Cross.
Prior to working for Everyday Health, he wrote, edited, copyedited, and fact-checked for books, magazines, and digital content covering a range of topics, including women's health, lifestyle, recipes, restaurant reviews, travel, and more. His clients have included Frommer's, Time-Life, and Google, among others.
He lives in Brooklyn, New York, where he likes to spend his time making music, fixing too-old electronics, and having fun with his family and the dog who has taken up residence in their home.
Don Rauf has been a freelance health writer for over 12 years and his writing has been featured in HealthDay, CBS News, WebMD, U.S. News & World Report, Mental Floss, United Press International (UPI), Health, and MedicineNet. He was previously a reporter for DailyRx.com where he covered stories related to cardiology, diabetes, lung cancer, prostate cancer, erectile dysfunction, menopause, and allergies. He has interviewed doctors and pharmaceutical representatives in the U.S. and abroad.
He is a prolific writer and has written more than 50 books, including Lost America: Vanished Civilizations, Abandoned Towns, and Roadside Attractions. Rauf lives in Seattle, Washington.
