Men who ate excessive quantities of ultra-processed foods had a 29% higher risk of developing colorectal cancer, according to a new study.
Researchers found that men who consumed high quantities of ultra-processed foods were at a higher risk of developing colorectal cancer than men who did not.
Due to ease and convenience, many Americans overlook the less-than-ideal nutritional information of pre-cooked and instant fare meals. However, a team of scientists led by researchers at Tufts University and Harvard University hopes that change will happen for many. After recently discovering a link between the high consumption of ultra-processed fare and an increased risk of colorectal cancer
Men who consumed excessive quantities of ultra-processed foods were at a 29% higher risk of developing colorectal cancer than men who consumed much smaller quantities, according to the BMJ. Colorectal cancer is the third most diagnosed cancer in the United States, but it was not discovered in women.
"We started out thinking that colorectal cancer might be the most impacted by diet compared to other cancer types," said Lu Wang, the study's lead author and a postdoctoral fellow at the Friedman School of Nutrition Science and Policy at Tufts. "Processed meats, most of which fall under the category of ultra-processed foods, are a significant risk factor for colorectal cancer. Ultra-processed foods are also high in added sugars and low in fiber,
In three large prospective studies that analyzed dietary intake and were conducted over more than 25 years, over 200,000 responses were collected. Each participant completed a food frequency questionnaire that asked about the frequency of consuming roughly 130 foods.
Ultra-processed foods were then categorized into quintiles, which ranged in value from the lowest to the highest, with those in the highest quintile at the highest risk of colorectal cancer. However, the study did not uncover an overall increase in risk for women who ate greater quantities of ultra-processed foods.
The differences in how men and women consume ultra-processed foods and the potential associated cancer risk were revealed in the analyses. Out of the 206,000 participants followed for more than 25 years, the research team documented 1,294 cases of colorectal cancer among men and 1,922 cases among women.
The most prominent association between colorectal cancer and ultra-processed foods among men comes from meat, poultry, or fish-based, ready-to-eat goods, according to Wang. “These products include some processed meats such as sausages, bacon, ham, and fish cakes. This is consistent with our hypothesis."
According to the study findings, a higher consumption of sugar-sweetened beverages, such as soda, fruit-based beverages, and sugary milk-based beverages, is linked to an increased risk of colorectal cancer in men.
Fang Fang Zhang, a cancer epidemiologist, and interim chair of the Friedman School's Division of Nutrition Epidemiology and Data Science, found an inverse relationship between ultra-processed dairy foods like yogurt and colorectal cancer risk among women.
There was no evidence that ultra-processed food consumption was linked to colorectal cancer risk among women. It's possible that women's composition could be different from that of men.
Zhang claims that yogurt, for example, may be effective in relieving the harmful effects of other ultra-processed foods in women.
Mingyang Song is the co-senior author on the study and assistant professor of clinical epidemiology and nutrition at the Harvard T.H. Chan School of Public Health. "Further research will need to determine whether there is a genuine sex difference in the associations, or whether or not the null findings in this study were simply due to chance or other uncontrolled confounding factors in women that mitigated the association."
Although ultra-processed foods are often linked to a poor diet quality, there may be other factors beyond the poor diet quality of ultra-processed foods that impact the risk of developing colorectal cancer.
Zhang noted that food additives may play a role in altering gut microbiota and promoting inflammation, which might also help with cancer development. Also, contaminants formed during food processing or migrated from food packaging might also help cancer development.
The team of researchers had ample data to process and review with over 90% follow-up rates for each of the three studies.
Song adds, "Cancer takes years or even decades to develop, and from our epidemiological studies, we have shown the potential latency effect." "Because of this lengthy process, it's important to have long-term exposure to data to better assess cancer risk."
- The Nurses’ Health Study (1986-2014): 121,700 registered female nurses between the ages of 30 and 55
- The Nurses’ Health Study II (1991-2015): 116,429 female nurses between the ages of 25 and 42
- The Health Professional Follow-up Study (1986-2014): 51,529 male health professionals between the ages of 40 and 75.
Investigators were presented with prospective data from 159,907 women from both NHS studies and 46,341 men from the Health Professional Follow-up Study following an exclusionary process.
Variable confounding factors include a family history of cancer, race, physical activity hours per week, smoking status, total alcohol intake and total caloric intake, regular aspirin usage, and menopausal status.
Zhang is aware that the conclusions for this cohort may differ from those for the general population because study participants may be more likely to eat well and avoid highly processed foods due to their careers in the healthcare sector. The statistics may also be skew due to changes in food processing methods during the last 20 years.
Zhang said, "But we are comparing within that population those who consume higher amounts versus lower amounts." "So those analyses are valid."
Wang and Zhang reported on an increase in ultra-processed food consumption among children and adolescents in the United States. Both studies support the hypothesis that many individuals may rely on highly processed foods as part of their daily diets.
Zhang, who serves as a member of the Tufts Institute for Global Obesity Research, believes that a lot of the dependence on these foods can be attributed to factors such as food accessibility and convenience. "We need to educate consumers about the dangers of consuming unhealthy foods in quantities and make healthier choices more accessible."
Although Wang believes that change will not occur overnight, she expects that this research study, among others, will contribute to changes in dietary regulations and recommendations.
Wang said that long-term change will require a multi-step approach. "Researchers continue to study how nutrition-related policies, dietary recommendations, and other healthy lifestyle behaviors, can improve overall health and reduce cancer burden.
Lu Wang, Mengxi Du, Kai Wang, Neha Khandpur, Jean-Philippe Drouin-Chartier, Mingyang Song, and Fang Fang Zhang, The BMJ, 31 August 2022, DOI: 10.136/bmj.o1972
The work presented in this article was supported by awards from the National Institutes of Health's National Institute on Minority Health and Health Disparities (R01MD011501), the National Cancer Institute (UM1CA087969; U01CA176726; U01CA167552; and R00CA215314), and the American Cancer Society's Mentored Research Scholar Grant in Applied and Clinical Research (Morgen