Most people associate colorectal cancer as a concern for those 50 or older. With roughly 90% of cases occurring in people older than 50, it makes sense. In the past decade, advanced cases of colon cancer and deaths have decreased—thanks to advances in screenings, and greater awareness of risk factors and symptoms.

But as cases drop among older populations, the opposite has been true for those younger than 50 in the U.S. and in Europe.

Dr. Minia Hellan, a surgical oncologist with Kettering Health, offers that “Since 2000, the incidence of colorectal cancer individuals younger than 50 years old have been increasing by two percent per year.”

And the trend doesn’t appear to be slowing.

“By 2030, it is estimated that one in four rectal cancers and one of 10 colon cancer cases will be patients below 50 years old.”

What’s causing the trend?

Among the potential causes, certain diets and habits may be to blame.

Some research suggests that sugary drinks—those with high-fructose corn syrup, are associated with advanced polyps in the colon. Similar studies show that women with diets high in sulfur had an increased risk of early-onset adenomas, or precancerous tumors. Processed meats can lead to excessive amounts of sulfur.

“They call it the ‘global westernization of the diet,’” says Dr. Hellan, “an increased intake of processed meats, red meat, high-fructose corn syrup, synthetic food dyes, and little-to-no vegetables.”

What’s troubling, though, is that the typical risk factors, such as family history, don’t appear to be helpful predictors.

“The larger studies say that half of the patients with colorectal cancer have no family history and no hereditary cancer syndrome,” says Dr. Hellan. “It’s likely that more than half have no genetic predisposition to cancer.”

What can be done?  

The best prevention method is to talk with family members and your primary care provider, and not to ignore symptoms. A common symptom is rectal bleeding. And don’t consider youth as a reason not to get screened.

“Just because you’re 30, don’t put symptoms off to the side,” warns Dr. Hellan. “Many of my colorectal cancer patients are younger than 50.”

More specifically, adults younger than 45 with higher risks should get screened at 40. Risks include a family history of colon cancer or radiation exposure. Those younger than 45 with symptoms but no additional risk factors, should talk to a primary care provider.