Plant-Based Eating May Prevent Digestive Cancers: 2022 Research Review

A 2022 study reviewing past research found strong evidence that eating more plant-based foods like fruits, vegetables, whole grains, nuts and legumes may lower a person's risk of developing cancers in the digestive system.

The study was a systematic review and meta-analysis, meaning it compiled and analyzed data from many other studies on the topic. It included 49 previous studies with over 3 million participants total. Of those participants, over 34,000 had been diagnosed with digestive system cancers.

The researchers found that people who most closely followed plant-based diet patterns were significantly less likely to develop common digestive cancers. Their analysis showed that these diets were associated with a:

• 18% lower risk of colorectal cancer

• 29% lower risk of pancreatic cancer

• 39% lower risk of liver cancer

The reduced cancer risk was observed both in studies that followed people over time (cohort studies) and studies that asked people to recall their past diets after a cancer diagnosis (case-control studies).

Several factors may help explain why plant-based eating protects against digestive cancers. Plant foods are high in fiber, vitamins, minerals and beneficial plant chemicals that reduce inflammation and oxidative damage in the body. Oxidative damage and chronic inflammation are known contributors to many cancers.

The researchers also noted the importance of gut health for cancer prevention. Eating lots of plant fiber helps nourish good gut bacteria, which crowds out harmful species. And substances in certain plant foods enhance the production of short-chain fatty acids - compounds that reduce gut inflammation.

Interestingly, the study found cancer risk was lowered by both pure vegan diets (no animal products) and other types of primarily plant-based diets, like Mediterranean-style eating (high in produce, grains and legumes with some fish, dairy and eggs). This suggests people don’t need to ban all animal foods to gain protection.

The researchers said their results align with dietary guidelines urging at least 5 servings of non-starchy produce daily and no more than 3 servings of red meat weekly. They concluded plant-based diets can play an important role in preventing digestive cancers.

So by filling your plate with more fruits, veggies, beans, nuts and whole grains, you may significantly slash your risk of developing common digestive cancers over your lifetime. Small steps toward plant-based eating can pay off in a healthier gut and better lifelong wellbeing.

Zhao Y, Zhan J, Wang Y, Wang D. The Relationship Between Plant-Based Diet and Risk of Digestive System Cancers: A Meta-Analysis Based on 3,059,009 Subjects. Front Public Health. 2022 Jun 3;10:892153. doi: 10.3389/fpubh.2022.892153. PMID: 35719615; PMCID: PMC9204183.