Eating yogurt linked to 20% lower risk of colorectal cancer
A new study links long-term yogurt consumption to reduced risk of certain colorectal cancers through gut microbiome changes.
Long-term yogurt intake may lower colorectal cancer risk by influencing gut bacteria. (CREDIT: CC BY-SA 4.0)
Yogurt, a fermented dairy product rich in beneficial bacteria, is widely recognized for its health benefits. Research suggests it may lower the risk of conditions such as inflammatory bowel disease, Clostridium difficile infection-related diarrhea, and type 2 diabetes.
Long-term consumption has also been linked to reduced cardiovascular disease mortality and overall lower mortality rates. More recently, yogurt has drawn attention for its potential role in lowering colorectal cancer risk.
A recent meta-analysis found that regular yogurt consumption is associated with a decreased risk of colorectal cancer. Scientists believe this effect may be due to yogurt’s influence on gut microbiota and intestinal barrier function.
Probiotic strains in yogurt, particularly Bifidobacterium, have been suggested to possess tumor-suppressive properties. However, the precise relationship between Bifidobacterium and colorectal cancer is still under investigation.
Previous studies have noted that colorectal cancer cases with Bifidobacterium presence exhibit certain cellular features, such as signet ring cell histology. This may indicate a weakened intestinal barrier, allowing bacteria to enter colonic tissues. Understanding how diet and gut bacteria interact in colorectal carcinogenesis could open new avenues for prevention and treatment strategies.
A Closer Look at the Data
To investigate the relationship between yogurt consumption and colorectal cancer, researchers from Mass General Brigham conducted an extensive study using data from two large-scale, long-term U.S. cohort studies: the Nurses’ Health Study (NHS) and the Health Professionals Follow-up Study (HPFS). These studies have tracked over 150,000 healthcare professionals since the 1970s and 1980s, collecting detailed lifestyle and dietary data, including yogurt intake.
Among the 3,079 documented colorectal cancer cases in these studies, 1,121 tumor samples were analyzed for Bifidobacterium DNA. About 31% of cases were Bifidobacterium-positive, while 69% were Bifidobacterium-negative.
Researchers found no significant association between yogurt consumption and overall colorectal cancer incidence. However, participants who consumed at least two servings of yogurt per week had a 20% lower risk of developing Bifidobacterium-positive tumors, particularly in the proximal colon—the right side of the large intestine.
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Proximal colon cancer is of particular concern due to its association with poorer survival outcomes compared to cancers in other parts of the colon. This finding suggests that yogurt may exert a protective effect by modifying the gut microbiome, specifically influencing Bifidobacterium abundance.
The Microbiome’s Role in Cancer
The gut microbiome plays a crucial role in maintaining digestive health and regulating immune responses. An imbalance in gut bacteria—known as dysbiosis—has been linked to chronic inflammation and increased cancer risk. Bifidobacterium is a key beneficial bacterial genus known to enhance intestinal barrier integrity, regulate immune responses, and inhibit tumor growth.
Dr. Shuji Ogino, chief of the Program in Molecular Pathological Epidemiology at Brigham and Women’s Hospital and senior author of the study, explained the significance of linking diet to microbiome changes in cancer. “Our study provides unique evidence about the potential benefit of yogurt. My lab’s approach is to try to link long-term diets and other exposures to a possible key difference in tissue, such as the presence or absence of a particular species of bacteria.”
The research team, known as OPTIMISTICC, is part of Cancer Grand Challenges, an initiative funded by Cancer Research UK and the U.S. National Cancer Institute. Their work aims to uncover how the microbiome influences cancer development and progression, with a focus on understanding rising early-onset colorectal cancer rates.
Dr. Tomotaka Ugai, co-senior author of the study, emphasized the specificity of the findings. “It has long been believed that yogurt and other fermented milk products are beneficial for gastrointestinal health. Our new findings suggest that this protective effect may be specific for Bifidobacterium-positive tumors.”
Future Research and Implications
While these findings add to the growing evidence of diet’s impact on cancer risk, more research is needed to confirm the role of yogurt and Bifidobacterium in colorectal cancer prevention. Scientists aim to explore how probiotic-rich foods influence gut bacteria and whether other dietary factors may enhance or hinder these effects.
Dr. Andrew T. Chan, chief of the Clinical and Translational Epidemiology Unit at Massachusetts General Hospital and co-lead of Cancer Grand Challenges team PROSPECT, highlighted the broader significance of these findings. “This paper adds to the growing evidence that illustrates the connection between diet, the gut microbiome, and risk of colorectal cancer. It provides an additional avenue for us to investigate the specific role of these factors in the risk of colorectal cancer among young people.”
The study underscores the importance of long-term dietary habits in shaping gut health. If further research supports these findings, yogurt could become a recommended dietary component for reducing colorectal cancer risk, particularly for individuals with a predisposition to proximal colon cancer.
Understanding the interplay between diet, gut bacteria, and disease progression may ultimately lead to more targeted prevention strategies.
Note: Materials provided above by The Brighter Side of News. Content may be edited for style and length.
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