Why are more young adults getting colorectal cancer?
March 10, 2026By: Trevin Lambert
Categories: Nutrition, Your Wellness
For decades, colorectal cancer, cancer of the colon, or large intestine, was considered a disease that primarily affected older adults. But in recent years, that narrative has quickly changed.
“We’re not seeing a small shift. It’s a big trend,” Rishi Grewal, MD, a gastroenterologist with NKC Health Gastroenterology, says. “Younger and younger patients are getting it now.”
That shift has caught the attention of physicians nationwide. While researchers continue to study the causes, Dr. Grewal says several key factors are already clear.
What’s behind the rise?
Colorectal cancer is the third-leading cause of cancer-related deaths in men and the fourth-leading cause in women in the U.S.
“There are multiple factors,” Dr. Grewal says. “But diet and nutrition are key factors.”
He points to modern eating patterns — particularly high consumption of nitrates, smoked meats and low-fiber diets — as significant contributors.
“Lack of fiber in the diet is a big predictor,” he says. “If you look at countries where diets are naturally high in fiber, colon cancer is way down the list. But when communities immigrate here and adopt Western diets, their risk increases within one generation.”
Environmental influences also play a role.
“We feel there are environmental causes, especially in younger patients, that we don’t fully understand yet,” Dr. Grewal explains. “Vitamin D and micronutrients may be part of it, along with genetic factors.
What symptoms should I watch out for?
Colorectal cancer can be subtle in its early stages.
“It can be a silent killer at times,” Dr. Grewal says.
But there are warning signs people, especially younger adults, shouldn’t dismiss:
- Blood in the stool
- Persistent bloating or a feeling of fullness
- Iron deficiency anemia or unexplained low blood counts
Dr. Grewal also stresses the importance of knowing your family history. “If your mother, father, or siblings have been diagnosed with colon cancer, let your physician know.”
What are the screening guidelines I should follow?
With increased awareness has come increased marketing for at-home stool tests. While those tools can play a role in diagnosis, Dr. Grewal is clear that a colonoscopy remains the gold standard.
“To prevent colon cancer, a colonoscopy is the best tool by far,” he says.
At-home tests may detect existing cancer, but they do not identify and remove precancerous polyps, which is what makes colonoscopy uniquely preventive.
“An at-home test can say you don’t have colon cancer right now,” he says. “But you could still have an advanced polyp that needs to be removed. Why risk it when you can get a colonoscopy and take care of it?”
Dr. Grewal adds, “Colon cancer is absolutely preventable. It’s the most preventable cancer out of all the malignancies. Nobody should avoid their colonoscopy.”
What can I do today to lower my risk?
While screening is critical, lifestyle choices matter, too.
“I think eating a Mediterranean diet is key,” Dr. Grewal says. “Eat your salads. Eat soluble fiber. Avoid nitrates. Avoid smoked meats.”
Experts in U.S. News & World Report ranked the Mediterranean diet as one of the healthiest ways to eat. People who follow the diet may experience health benefits, including:
- Reduced risk of cancer and heart disease, and strokes in women
- Improved brain and gut health
Now, passing up smoked meat for the Mediterranean diet can be tough in barbecue-loving communities like Kansas City, but small changes can make a difference. Here are some foods that are good for your colon health, and may reduce the risk of colorectal cancer:
- Leafy greens (spinach, kale)
- Cruciferous vegetables (broccoli, cabbage)
- Berries, apples, pears
- Whole grains like brown rice, quinoa, oats
- Beans, lentils and peas
And while some popular diet trends focus heavily on red meat consumption, Dr. Grewal urges caution. According to Mayo Clinic, eating red and processed meat can raise your risk of developing certain types of cancer.
Some other lifestyle changes, such as limiting alcohol consumption and cutting out ultra-processed foods like chips, sugary snacks or frozen dinners, also show benefits for lowering the risk of cancer.
In addition to diet and screening, emerging research suggests a potential benefit from GLP-1 receptor agonist medications, a class of drugs most commonly used for type 2 diabetes and weight management. Dr. Grewal notes emerging breakthroughs in cancer prevention around GLP-1 medications.
“GLP-1s are actually reducing colon cancer risk,” Dr. Grewal says. “The impact has been dramatic across multiple areas of health.”
In fact, a recent study found that people taking GLP-1 receptor agonists had a significantly lower risk of developing colorectal cancer compared with those taking aspirin. In this study, GLP-1 medication users saw about a 26% reduction in colorectal cancer risk overall, with benefits seen across age and weight groups.
The bottom line
Colorectal cancer is rising among younger adults, but it is also highly preventable. According to the CDC, the most effective way to reduce your risk of colorectal cancer is regular screenings beginning at age 45. Dr. Grewal says getting a colonoscopy remains the gold standard in detecting cancer inside the rectum and the entire colon. During the procedure, doctors can find and remove most polyps and some cancers.
“Despite us doing 40 or 50 procedures a day, we’re still not doing enough,” Dr. Grewal says. “Get your appointments. Get your screening tests done. Control what you can.”
The most powerful tools we have are awareness and action. If you have symptoms, a family history or are due for screening, don’t wait. Learn more about prevention and talk with your doctor today.
