Women who regularly consume large quantities of ultra-processed foods face a dramatically increased risk of developing pre-cancerous growths in their bowel, according to groundbreaking new research published in Jama Oncology.
Significant Findings from Long-Term Study
The comprehensive study monitored 29,105 women with an average age of 45 over several decades, collecting detailed food surveys from participants every four years between 1991 and 2015. The research was funded by Cancer Grand Challenges, a global research initiative founded by Cancer Research UK and the US National Cancer Institute.
Analysis revealed that women who frequently consumed UPFs including processed sauces, crisps, processed meats and ready meals had a 45% higher likelihood of developing adenomas – a type of polyp that can develop into bowel cancer over time – compared to those with the lowest consumption levels.
The Alarming Rise in Early-Onset Bowel Cancer
Researchers identified 1,189 cases of early-onset adenomas among the study participants. This finding is particularly significant given the concerning trend in bowel cancer rates among younger adults. According to Cancer Research UK, incidence rates of bowel cancer among people aged 25-49 have increased by 62% since the early 1990s.
Dr Andrew Chan, lead author of the study from Harvard Medical School and Massachusetts General Hospital, explained: "We're seeing more cases of bowel cancer in younger adults, and we still don't understand why. Our research is exploring possible factors such as diet, lack of exercise and disruption to the gut microbiome, which may all play a role."
Understanding the Dietary Impact
The study highlighted stark differences in consumption patterns between groups. Women with the highest UPF intake consumed approximately 9.9 portions daily, while those with the lowest intake averaged just 3.3 servings each day.
Cancer Research UK illustrated what a high-UPF diet might typically include:
- Breakfast: Sweetened cereal, white toast with margarine or jam, flavoured yoghurt or breakfast bar
- Lunch: Pre-packaged sandwich, crisps, and a can of cola or flavoured drink
- Dinner: Frozen pizza or oven chips with chicken nuggets, ketchup and mayonnaise
- Evening snack: Ice cream or biscuits
Fiona Osgun, head of health information at Cancer Research UK, emphasised: "While this study doesn't directly measure cancer risk, it offers useful insight into how diet might influence early changes in the bowel that sometimes lead to cancer. Our overall diet matters more for cancer risk than any single food type."
The authors concluded that these findings "highlight the important role of UPFs in early-onset colorectal tumorigenesis and support improving dietary quality as a strategy to mitigate the increasing burden of early-onset colorectal cancer."
Dr Chan added that while the study suggests these foods could be linked to higher polyp risk, "more research is needed to confirm this link, including looking at larger and more diverse groups of people and investigating how the body responds to these foods."
