New study links ultra-processed foods to rising colon cancer risk among young adults

OAKLAND, Calif. - A new study suggests a strong link between eating ultra-processed foods and an increased risk of developing early signs of colon cancer — adding to growing concern among cancer experts about rising diagnoses in younger adults.

Researchers at the Mass General Brigham Cancer Institute analyzed data from nearly 30,000 young, healthy women and found that higher consumption of ultra-processed foods was associated with a greater likelihood of developing colorectal precursor lesions known as colon adenomas.

Ultra-processed foods include items made with industrial ingredients not typically found in home kitchens. They’re often packaged, heavily preserved and, according to public health estimates, make up about 70% of the average American diet.

What they're saying:

Dr. Katherine Van Loon, a UCSF professor and director of the UCSF Global Cancer Program, said the findings offer an important clue in understanding the rise of colorectal cancer among younger adults — a trend she sees firsthand.

"Every patient in my clinic is very, very young," Van Loon said. "We’re seeing decreasing rates in people over 45, but rising rates in younger people. This is resulting in a rising mortality rate from an otherwise preventable disease."

Previous research has linked early-onset colorectal cancer to obesity, Type 2 diabetes, sedentary lifestyles and diets high in red and processed meats and sugars. But Van Loon says many young patients she treats don’t fit those patterns.

"That’s why this study is so important," she said. "It adds another layer to what may be driving this epidemic."

While the study did not break down specific foods, Van Loon said ultra-processed items generally include boxed soups, frozen meals and other convenient products with long shelf lives — foods many Americans grew up eating in the 1970s, ’80s and ’90s.

Van Loon believes it’s not too late for people to adopt healthier habits.

"We know from tobacco research that when someone stops smoking, their cancer risk decreases," she said, suggesting the same could be done to reverse the negative effects of decades of ultra-processed food consumption. "It’s not too late to intervene, stop bad habits and pass on good ones to younger generations."

What you can do:

She recommends prioritizing fresh foods, including vegetables and unprocessed meats, and urges anyone 45 or older to get screened for colorectal cancer.

 She also stressed the importance of taking symptoms seriously at any age.

"If someone is experiencing bowel changes, blood in their stool, abdominal pain, cramping or unexplained weight loss, they should see a doctor," she said. "Just because you’re not yet 45 doesn’t mean those symptoms don’t need medical attention."

Van Loon says awareness — and earlier action — could help reverse the troubling trend.