New study links ultra-processed foods to colorectal cancer in men

For many Americans, the convenience of ready-to-eat meals may make it easy to overlook less-than-ideal nutritional information, but recently a team led by researchers from Tufts and Harvard Universities found that ultra-processed foods consumption and increased risk of colorectal cancer.

In a study published on August 31, BMJMoreresearchers found that men who consumed high levels of ultra-processed foods had a 29% higher risk of developing the disease. colorectal cancer— Third diagnosed patient cancer In the United States, men consumed much less. They did not find the same association in women.

“We started to think that colorectal cancer might be the cancer most affected by diet compared to other types of cancer,” said lead author of the study, Friedman of Tufts. said Lu Wang, a postdoctoral fellow at the Graduate School of Nutritional Sciences and Policy. “Processed meats, most of which fall into the ultra-processed food category, are strong risk factors for colorectal cancer. Ultra-processed foods are also high in added sugars and low in fiber, which contributes to weight gain and obesity.” Obesity is an established risk factor for colorectal cancer.”

This study analyzed responses from over 200,000 participants (159,907 women and 46,341 men) and evaluated three large prospective studies. dietary intake It has been practiced for over 25 years. Each participant received a food frequency questionnaire every 4 years and was asked about the frequency of eating approximately 130 foods.

for research in BMJMore, participants’ ultra-processed food intake was classified into quintiles ranging in value from lowest to highest consumption. People in the highest quintile were identified as having the highest risk of developing colorectal cancer. Although a clear association was identified for colorectal cancer in men, especially in the distal colon, this study did not find an overall increased risk for women who consumed large amounts of ultra-processed foods. I did.

Impact of ultra-processed foods

The analysis reveals differences in how men and women consume ultra-processed foods and the associated cancer risks. After following 206,000 participants over his 25 years, the research team documented 1,294 cases of colorectal cancer in men and 1,922 cases in women.

The team found that the strongest associations between colorectal cancer in men and ultra-processed foods came from ready-to-eat products based on meat, poultry, or fish. contains processed meats such as sausages, bacon, ham, and fish cakes, which is consistent with our hypothesis,” said Wang.

The team also found that the higher the consumption of sugar-sweetened beverages, such as soda, fruit-based beverages, and sugar-sweetened milk-based beverages, the higher the risk of colorectal cancer in men.

However, not all ultra-processed foods are equally harmful when it comes to colorectal cancer risk. “We found an inverse association between ultra-processed dairy products such as yogurt and colorectal cancer risk in women,” said co-lead author, cancer epidemiologist, Friedman School of Nutrition and Epidemiology. Fang Fang Zhang, Interim Chairman of the Data Science Division, said. .

Overall, there was no association between ultra-processed food consumption and colorectal cancer risk in women. The composition of ultra-processed foods consumed by women may differ from that of men.

“Foods like yogurt can potentially counteract the detrimental effects that other types of ultra-processed foods have on women,” says Zhang.

Mingyang Song, co-lead author of the study and assistant professor of clinical epidemiology and nutrition at the Harvard TH Chang School of Public Health, added: The invalid results in women in this study are only due to chance or other uncontrolled confounding factors in women that moderate the association. “

Although ultra-processed foods are often associated with poor dietary quality, there may be factors other than a poor ultra-processed diet that influence the risk of developing colorectal cancer.

Alteration of the gut microbiota, promotion of inflammation, and the potential role of food additives in contaminants formed during food processing or transferred from food packaging may all promote cancer development. Mr Zhang pointed out that there is.

Data analysis

The research team had sufficient data to process and review, as the follow-up rate from each of the three studies was over 90%.

“Cancer takes years, even decades, to develop. epidemiological studies, showed potential impacts.It will take years to confirm the effects of specific exposures on cancer risk.Song said: “

Research includes:

After an exclusion process for previous diagnoses or incomplete investigations, researchers were left with prospective data from 159,907 women and 46,341 men from both NHS studies.

The team assessed factors such as race, family history of cancer, endoscopy history, hours of physical activity per week, smoking status, total alcohol and total caloric intake, regular aspirin use, and menopausal status. We adjusted for potential confounders.

Zhang acknowledges that the participants in these studies all worked in the medical field, so the findings in this population may not be the same as those in the general population. Ultra-processed food. The data may also be skewed due to processing changes over the last 20 years.

“But within that population we are comparing people who consume more and those who consume less. “So those comparisons are valid.”

changing eating patterns

Wang and Zhang previously published the following study. identified a trend Increased consumption of ultra-processed foods among US children and adolescents. Both studies underscore the idea that many different groups of people may rely on ultra-processed foods in their daily diets.

“Many of these food dependencies can be attributed to factors such as food access and convenience,” said Zhang, who is also a member of the Tufts Institute for Global Obesity Research. “While chemically processed foods can help extend shelf life, many processed foods are no healthier than their unprocessed alternatives. We need to make people aware and help them make healthier choices.”

Wang knows that change won’t happen overnight and, among other things, hopes this research will contribute to changes in dietary regulations and recommendations.

“Long-term change requires a multi-step approach,” added Wang. “Researchers are finding ways to improve overall health and reduce the burden of cancer by changing nutrition-related policies, dietary recommendations, recipes and formulas, combined with other healthy lifestyle habits. As we continue to investigate, it is important that we continue to study the associations between cancer and diet, and potential interventions to improve outcomes.”