March is Colorectal Cancer Awareness Month, and the data is sobering: colorectal cancer is now one of the leading causes of cancer-related death in the United States. While rates have declined in adults over 65, incidence is rising sharply in younger populations, particularly Generation X.
Between 1988 and 2015, colorectal cancer rates in adults under 50 increased by 63% in the U.S. Gen X—now between the ages of 45 and 60—sits directly at the center of this trend.
So what’s driving this increase, and more importantly, what can be done to reduce risk?
Why Colon Cancer Is Increasing in Gen X
While there are genetic factors that contribute to cancer development, lifestyle and environmental factors appear to be contributing to the rise in colorectal cancer among younger adults.
From a nutrition standpoint, modern, Western diets are playing a major role. Increased consumption of ultra-processed foods and processed meats, combined with low fiber intake, higher added sugar, and frequent consumption of sugary beverages, has significantly altered gut health and metabolic function. Research shows that drinking two or more sugary beverages per day more than doubles the risk of colon cancer.
A sedentary lifestyle further compounds this risk. Physical inactivity, along with rising rates of obesity and metabolic syndrome, is strongly associated with colorectal cancer development.
There is also growing evidence that frequent or prolonged antibiotic use may increase risk by disrupting the gut microbiome—an area of active and ongoing research.
What Gen X Can Do Today to Lower Risk
The good news is that many of the most impactful risk factors are modifiable. Small, consistent changes can meaningfully reduce long-term risk.
Prioritize fiber intake.
More than 90% of U.S. adults do not consume enough fiber. According to the National Academy of Medicine, women aged 50 and under should aim for at least 25g of fiber daily, and men 38g. After age 50, recommended intake is 21g for women and 31g for men. In clinical practice, fiber goals are often individualized and may be slightly higher if well tolerated. A fiber-rich diet should emphasize vegetables, whole grains, legumes, fruit, nuts, seeds, and calcium-rich foods. Learn more on the importance of Fiber in our recent blog post.
Move your body regularly.
Long-term studies show that engaging in five hours of brisk walking per week or two hours of running, sustained over decades, significantly reduces the risk of digestive cancers. While the greatest benefit is seen with long-term consistency, it is never too late to start.
Reduce dietary risk factors.
Avoid processed meats and ultra-processed foods, and cut back on added sugar and sugary beverages whenever possible.
Limit or eliminate alcohol.
Reducing alcohol intake—or stopping altogether—has been shown to lower the risk of developing precancerous colon lesions (adenomas).
Check and optimize vitamin D levels.
Very low vitamin D levels (<12 ng/mL) are associated with a 31% higher risk of colon cancer compared to sufficient levels. Vitamin D deficiency is common, and most adults should aim for levels at or above 30 ng/mL. Higher levels may confer added benefit, however we also don’t want to over supplement vitamin D. In our medical practice, we regularly monitor levels and supplement vitamin D accordingly.
Get screened.
Routine screening colonoscopies should begin at age 45, or earlier for individuals with a family history, genetic risk, inflammatory bowel disease, or other risk factors. Screening can detect both early-stage cancers and precancerous lesions that can be removed before they become malignant. Other screening tests include flexible sigmoidoscopy, CT colonography or fecal tests. Of the stool tests, multi-target stool DNA (mt-sDNA) tests have the highest sensitivity for colorectal cancer. When we screen with a fecal test, our practice uses mt-sDNA test, Cologuard. Screening intervals depend on modality of screening, risk factors, family history and findings on prior screening (e.g., adenoma(s) on colonoscopy for which follow up screening would be done earlier than usual). Other instances where colonoscopy may be done outside of usual screening is for blood in stool, new onset of constipation, pencil thin stool, unexplained iron deficiency anemia or unintended weight loss.
The Bottom Line
Colorectal cancer is increasingly affecting adults in midlife—but it is also one of the most preventable and treatable cancers when caught early. Nutrition, movement, micronutrient status, and timely screening all play a critical role in reducing risk.
Awareness is the first step. Action is the second.
References
Contributing Factors & Risk Research
https://pubmed.ncbi.nlm.nih.gov/37213277/
https://www.gastrojournal.org/article/S0016-5085(19)40882-2/fulltext
https://pubmed.ncbi.nlm.nih.gov/34921228
https://pubmed.ncbi.nlm.nih.gov/37504220
Prevention, Screening & Lifestyle Risk Reduction
https://jamanetwork.com/journals/jamaoncology/fullarticle/2840507
https://acsjournals.onlinelibrary.wiley.com/doi/10.1002/cncr.70201