Alarming Rise in Early-Onset Colorectal Cancer: Could Your Diet Be to Blame?
Colorectal cancer, once predominantly associated with older adults, is now increasingly diagnosed in individuals aged 50 and younger, particularly in high-income countries like the United States. This shift has left researchers scrambling to understand the underlying causes. But here's where it gets controversial: a groundbreaking study led by Mass General Brigham researchers as part of the Cancer Grand Challenges PROSPECT team suggests a startling link between ultra-processed foods and the precursors to early-onset colorectal cancer (EOCRC).
By examining the diets and endoscopy results of nearly 30,000 women over 24 years, the team uncovered a striking pattern: those who consumed the highest levels of ultra-processed foods had a 45% greater risk of developing adenomas—potential precursors to colorectal cancer—compared to those with the lowest intake. These findings, published in JAMA Oncology, shed new light on the role of diet in this alarming trend. (https://jamanetwork.com/journals/jamaoncology/fullarticle/10.1001/jamaoncol.2025.4777)
And this is the part most people miss: ultra-processed foods, often packed with sugar, salt, saturated fats, and additives, now make up a staggering 35% of the average American's daily calorie intake. While this study doesn’t claim these foods are the sole culprit behind the rise in EOCRC, it does suggest a strong, dose-dependent relationship. As senior author Dr. Andrew Chan, a gastroenterologist and chief of the Clinical and Translational Epidemiology Unit at Mass General Brigham, explains, “The more ultra-processed foods you eat, the higher the potential for developing colon polyps.”
This isn’t the first time Dr. Chan’s team has linked ultra-processed foods to colorectal cancer, but it’s the first study to specifically focus on early-onset cases. Drawing from the Nurses’ Health Study II, a long-term study of female nurses born between 1947 and 1964—a demographic at elevated risk for EOCRC—the researchers analyzed dietary surveys and endoscopy data from 29,105 participants. Despite the self-reported nature of the dietary data, this method has been validated for its accuracy in reflecting long-term eating habits.
On average, participants consumed 5.7 servings of ultra-processed foods daily, slightly below the national U.S. average. Yet, those who consumed the most (around 10 servings per day) faced a 45% higher risk of developing conventional adenomas compared to those who consumed the least (around 3 servings per day). Interestingly, no such link was found with serrated lesions, another type of colorectal cancer precursor.
Here’s where it gets even more intriguing: even after accounting for other risk factors like body mass index, type 2 diabetes, and low fiber intake, the association between ultra-processed foods and adenomas remained significant. However, Dr. Chan is quick to point out that diet alone doesn’t fully explain the rise in EOCRC. “We see many individuals in our clinic with early-onset colon cancer who eat very healthy diets,” he notes, emphasizing the need to identify other contributing factors.
The study also highlights the complexity of categorizing ultra-processed foods. Not all foods in this category may pose the same level of risk, and researchers are working to refine these classifications. As part of the Cancer Grand Challenges PROSPECT team, Dr. Chan and his colleagues are committed to uncovering the multifaceted causes of EOCRC.
So, what does this mean for you? While more research is needed, reducing ultra-processed food intake could be a proactive step toward lowering your risk. But here’s a thought-provoking question: In a world where convenience often trumps nutrition, how can we balance our dietary choices with our health? And could this study be the tipping point that sparks a broader conversation about the role of food in cancer prevention?
Let us know your thoughts in the comments—do you think ultra-processed foods deserve more scrutiny, or is this just another dietary trend? The debate is far from over, and your perspective could be the next piece of the puzzle.
Reference: Wang C, Du M, Kim H, et al. Ultraprocessed Food Consumption and Risk of Early-Onset Colorectal Cancer Precursors Among Women. JAMA Oncol. 2025. doi:10.1001/jamaoncol.2025.4777 (https://doi.org/10.1001/jamaoncol.2025.4777)
This article has been republished from Mass General Brigham. Note: material may have been edited for length and content. For further information, please contact the cited source. Our press release publishing policy can be accessed here: (https://www.technologynetworks.com/tn/editorial-policies#republishing).
