The GutFit Nutrition Podcast · Leigh Merotto, Dietitian | IBS, Gut Health and Fitness Expert

46: Colon Cancer: Rising Rates & 5 Evidence Based Strategies to Lower Your Risk

·37 min·2 clips

A 2018 meta-analysis linked the lowest fiber intake with 21% higher distal colon cancer risk.

1. The Gut Fit Nutrition Podcast episode focuses on colorectal cancer, rising rates in younger adults, and five evidence-based prevention strategies. 2. Leigh Murado is the host, a registered dietitian and gut health expert, and she frames the topic around her work with IBS clients and recreational athletes. 3. The episode argues that colorectal cancer risk can be lowered through diet and lifestyle choices backed by systematic reviews and meta-analyses. 4. Murado says an American Cancer Society update showed colorectal cancer is now the leading cause of cancer-related deaths in adults under 50. 5. She adds that overall cancer mortality in U.S. adults younger than 50 fell from 25.5 deaths per 100,000 in 1990 to 14.2 in 2023. 6. She notes that colorectal cancer mortality has been increasing by 1.1% per year since 2005, unlike the other leading cancer death categories she names. 7. The episode defines colorectal cancer as uncontrolled cell growth in the colon or rectum and lists symptoms such as blood in stool, bowel habit changes, abdominal pain, unintended weight loss, fatigue, and weakness. 8. Murado says early colon cancer often has no symptoms, which is why family history and screening timing matter. 9. She says colonoscopy is the best way to screen and prevent colon cancer because polyps can be found and removed before they become cancerous. 10. She identifies ulcerative colitis, Crohn's disease, low-fiber diets, high saturated fat intake, obesity, low physical activity, smoking, and red or processed meat intake as risk factors. 11. She explicitly says IBS is not the same as inflammatory bowel disease and does not increase colorectal cancer risk on its own. 12. The first prevention strategy is dietary fiber, and she cites a 2018 meta-analysis showing 21% higher distal colon cancer risk and 14% higher proximal colon cancer risk at the lowest fiber intake. 13. She explains that soluble fiber from foods like rolled oats, chia seeds, ground flaxseed, legumes, rice, and potatoes is fermented by gut bacteria in the large bowel. 14. She says that fermentation produces short-chain fatty acids, especially butyrate, which may help regulate intestinal pH and protect colon tissue. 15. She adds that enough fiber supports intestinal transit time, with an ideal range she gives as roughly 20 to 30 hours. 16. The second strategy is whole grains, and she cites a dose-response meta-analysis showing a 10% reduction in colorectal cancer risk for each 10 grams per day of fiber. 17. She names quinoa, wild rice, buckwheat, millet, and amaranth as examples of whole grains, and she says three servings or about 90 grams per day were linked with a 20% lower risk. 18. The third strategy is a whole-food dietary pattern, and she cites a 2025 systematic review with 29 studies showing lower colon and rectal cancer risk with more vegetables, fruits, legumes, and whole grains. 19. The fourth and fifth strategies are regular physical activity and canned fish intake, with a meta-analysis of 126 studies showing about 19% lower colon cancer risk in highly active people and Italian case-control studies linking canned tuna, mackerel, and sardines in oil with lower colorectal cancer incidence. 20. The episode uses an educational, advice-driven tone, includes repeated references to earlier episodes 22 and 40, and will likely help people interested in gut health, prevention, and fiber-first nutrition; it may be less useful for listeners wanting a deep oncology discussion or a purely clinical screening guide.

As heard by us

A clear, evidence-first look at colorectal cancer risk, fiber, and research literacy.

This episode treats colorectal cancer risk as something worth understanding rather than fearing. It points to a 2018 meta-analysis showing that people with the lowest dietary fiber intake had a 21% higher risk of distal colon cancer and a 14% higher risk of proximal colon cancer…

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You want a calmer, evidence-first take on colorectal cancer risk and what to do about it.

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