A major JAMA Oncology study links diets heavy in ultra-processed foods to significantly higher rates of precancerous colon polyps, a finding that carries important implications for California families and Latino communities.
The chips, sugary drinks, processed meats, and packaged snacks many Americans eat every day could be doing more than adding calories. New research suggests they may also increase the risk of developing precancerous growths in the colon, particularly among younger adults.
A new study published in JAMA Oncology found that women who consumed the highest amounts of ultra-processed foods, averaging about 10 servings a day, had a 45 percent higher risk of developing conventional adenomas, a common type of precancerous colorectal polyp, compared with women who ate the least.
The findings arrive at a time when doctors are increasingly concerned about rising rates of early-onset colorectal cancer, defined as colon and rectal cancers diagnosed before age 50.
For California families and Latino communities, the study raises important questions about diet, food access, and the growing burden of colorectal disease among younger adults.
Researchers from the Mass General Brigham and Harvard University followed more than 29,000 women over approximately 24 years through the long-running Nurses’ Health Study II.
Participants who consumed the highest levels of ultra-processed foods were significantly more likely to develop conventional adenomas, which can eventually become cancerous if left undetected.
Researchers did not find a significant association between ultra-processed foods and serrated lesions, another type of colorectal growth that generally develops more slowly.
Scientists believe ultra-processed foods may contribute to cancer risk through several biological pathways. Diets high in processed foods are often associated with chronic inflammation, changes to the gut microbiome, insulin resistance, and obesity, all factors that have been linked to colorectal cancer development.
What Counts as Ultra-Processed Food?
Ultra-processed foods are industrially manufactured products that often contain ingredients rarely found in home kitchens, including preservatives, flavor enhancers, emulsifiers, and artificial additives.
Examples commonly associated with these diets include:
- Processed and red meats
- Sugary beverages and soft drinks
- Ultra-processed breakfast cereals
- Refined grain products
- Packaged savory snacks such as chips and crackers
- Fast-food items and heavily processed frozen meals
Many of these foods are inexpensive, heavily marketed, and widely available, making them difficult to avoid for busy families.
Why Latino Communities Should Pay Attention
The study included Latina participants, but they represented only a small percentage of the study population. The Nurses’ Health Study II is overwhelmingly non-Hispanic White, reflecting the demographics of the nursing workforce when the study began in 1989.
Because of this limited representation, researchers did not publish Latino-specific findings.
However, public health experts say the findings remain highly relevant.
Colorectal cancer rates have been increasing among younger adults across the United States, including among Hispanics. Studies have also found that Hispanic patients are frequently diagnosed at later stages of colorectal cancer, when treatment becomes more difficult and survival rates decline.
California’s Latino population also faces persistent challenges that can influence dietary choices and health outcomes, including economic pressures, food insecurity, neighborhoods with limited access to fresh produce, and aggressive marketing of sugary drinks and processed foods.
The biological mechanisms identified by researchers, including inflammation and changes in gut bacteria, are not limited by race or ethnicity.
Key Takeaways
Higher intake of ultra-processed foods was associated with:
- A 45 percent higher risk of developing conventional precancerous adenomas
- Greater exposure to foods linked to chronic inflammation
- Potential changes in gut health associated with colorectal disease
Foods experts suggest eating more often:
- Dark leafy greens
- Whole grains
- Beans and legumes
- Fruits and vegetables
- Minimally processed proteins
Health experts often recommend “crowding out” ultra-processed foods by first filling meals with nutrient-rich whole foods rather than trying to eliminate processed foods all at once.
What About Colon Cancer Screening?
The findings are especially timely because colorectal cancer is increasingly being diagnosed in younger adults.
The American Cancer Society recommends that people at average risk begin colorectal cancer screening at age 45.
Individuals with a family history of colorectal cancer, inflammatory bowel disease, or certain genetic conditions may need to start screening earlier and should discuss their risk factors with a healthcare provider.
Possible warning signs include:
- Persistent changes in bowel habits
- Blood in the stool
- Unexplained weight loss
- Ongoing abdominal pain
- Unusual fatigue
These symptoms do not necessarily mean someone has cancer, but experts say they should never be ignored.
What California Families Should Watch Next
Researchers continue to investigate why colorectal cancer is increasing among adults under 50 and how diet, obesity, environmental exposures, and changes in the gut microbiome may be contributing to the trend.
For California families, particularly those navigating high food costs and uneven access to healthy foods, the study serves as another reminder that everyday eating habits can have long-term health consequences.
The message from researchers is not that an occasional bag of chips or soda causes cancer. Rather, consistently relying on ultra-processed foods as a major part of the diet may increase the likelihood of developing the kinds of precancerous growths that can eventually lead to colorectal cancer.
As early-onset colorectal cancer continues to rise, experts say prevention through healthier eating patterns and timely screening may be among the most powerful tools available.
