Recent studies are uncovering how diet can impact the risk of gastrointestinal cancers. Image credit: Trent Lanz/Stocksy. Multiple studies have indicated that dietary choices can influence the risk of cancer, particularly gastrointestinal cancers. Recent findings further support this notion, demonstrating how specific foods can either decrease or increase the risk of various types of cancer. A study from January 2025 suggests that consuming cow’s milk and other calcium-rich foods may lower the risk of colorectal cancer. Another study from the same month reveals that fiber-rich foods could reduce the risk of colorectal cancer by activating certain genes in gut bacteria. Additionally, a study published in December 2024 suggests that drinking four cups of coffee daily is associated with a decreased risk of head and neck cancer. Numerous studies over the years have highlighted the link between diet and cancer risk, particularly gastrointestinal cancers. For example, the consumption of red and processed meats has been linked to an increased risk of various cancers, including breast, endometrial, and colorectal cancer. Conversely, diets abundant in fruits and vegetables, such as the Mediterranean diet, are associated with a lower risk of cancer. Recent evidence underscores the significant role of diet in cancer risk and prevention. Daily calcium intake associated with reduced colorectal cancer risk A study published in Nature Communications in January 2025 found that regular consumption of calcium-rich foods and beverages is linked to a lower risk of colorectal cancer. The research, conducted by experts from the University of Oxford in the UK and involving over 542,000 participants in the Million Women Study, revealed that individuals who consumed dairy products like milk and yogurt, as well as foods containing riboflavin, magnesium, phosphorus, and potassium, had a reduced risk of colorectal cancer. Specifically, the study showed that individuals who consumed an additional glass of milk daily or 300 milligrams of calcium had a 17% lower relative risk of developing colorectal cancer. Tom Sanders, PhD, a nutrition and dietetics professor emeritus at King’s College London, highlighted the protective role of dietary calcium and riboflavin in reducing cancer risk. He also mentioned a potential link between wholegrain cereals and colorectal cancer prevention, possibly due to their consumption alongside milk. The mechanism behind calcium’s protective effect against colorectal cancer could involve binding to bile acids in the gut, preventing their harmful impact on the gut lining. How do fiber-rich foods safeguard against colorectal cancer? Previous research has suggested that fiber-rich foods, such as vegetables, whole grains, fruits, and nuts, may have a protective effect against colorectal cancer. A study featured in Nature Metabolism in January 2025 provides insight into the potential mechanism supporting this protective role. The study emphasized that the breakdown of plant fiber by gut bacteria could play a crucial role in reducing the risk of colorectal cancer.
In the gut, two types of molecules are produced known as short-chain fatty acids, which may play a role in preventing cancer. Specifically, researchers identified propionate and butyrate as the key short-chain fatty acids that can impact gene expression in both healthy cells and colon cancer cells obtained from humans. These short-chain fatty acids have the ability to influence the activity of genes that either promote cancer (proto-oncogenes) or suppress it (tumor-suppressor genes) by altering histones, the proteins that aid in DNA packaging. By making DNA more accessible, short-chain fatty acids can activate or deactivate specific genes based on the cell type and environmental conditions, as explained by Şebnem Ünlüişler, a genetic engineer and Chief Longevity Officer at the London Regenerative Institute.
Moreover, this process can inhibit histone deacetylases enzymes, resulting in modifications to DNA packaging that can impede cancer cell growth or even induce cell death. Additionally, an intriguing recent discovery revealed that consuming more than four cups of caffeinated coffee daily was linked to a reduced risk of neck and head cancer. This finding was reported in a study published in December 2024 in the journal Cancer, which analyzed data from the International Head and Neck Cancer Epidemiology Consortium (INHANCE), incorporating data from 14 individual-level case-control studies.
The protective effect associated with consuming four or more cups of coffee per day extended to mouth and oropharyngeal cancers. Kanwar Kelley, MD, JD, a board-certified otolaryngologist (ENT) and the co-founder and CEO of Side Health, highlighted these findings. He noted that the reduced risk of head and neck cancers was particularly evident with increased coffee or tea consumption, with the most significant impact observed in individuals drinking more than four cups of caffeinated coffee daily but less than or up to one cup of tea.
Nevertheless, Kelley cautioned that the quantity of coffee required to achieve this protective effect might be excessive for some individuals. He pointed out that for those sensitive to caffeine, consuming such high amounts of coffee could pose challenges in experiencing the benefits. Emphasizing the key takeaway, Kelley stressed that enjoying a morning cup of coffee is still permissible without the need to increase consumption beyond normal levels for protection against head and neck cancer.
