Study Finds That Ultra Processed Foods Increases The Risk Of Colorectal Cancer In Men By 29 Percent!

Researchers from Tufts University, Boston-USA has found that frequent consumption of ultra-processed foods increases the risk of colorectal cancer in men.


 
The researchers and doctors from Harvard T.H. Chan School of Public Health-USA, Boston, University of São Paulo-Brazil, Universidade Federal de Uberlândia, Minas Geras-Brazil, Université Laval, Québec-Canada, Brigham and Women’s Hospital, Boston-USA and Massachusetts General Hospital-USA were also involved in the study.
 
Ultra-processed foods are foods that go through multiple processes (extrusion, molding, milling, etc.) and contain many added ingredients and are highly manipulated. Examples are soft drinks, chips, chocolate, candy, ice-cream, sweetened breakfast cereals, packaged soups, chicken nuggets, hotdogs, fries, cakes, muffins, burgers, salad dressings, sauces, cured meats and more.
 
The study team conducted a detailed analysis to examine the association between consumption of ultra-processed foods and risk of colorectal cancer among men and women from three large U.S. based prospective cohorts with dietary intake assessed every four years using food frequency questionnaires.
 
The study participants included: men (n= 46 341) from the Health Professionals Follow-up Study (1986-2014) and women (n=159 907) from the Nurses’ Health Study (1986-2014; n=67 425) and the Nurses’ Health Study II (1991-2015; n=92 482) with valid dietary intake measurement and no cancer diagnosis at baseline.
 
Association between ultra-processed food consumption and risk of colorectal cancer was estimated using time varying Cox proportional hazards regression models adjusted for potential confounding factors.
 
The study found 3216 cases of colorectal cancer (men, n=1294; women, n=1922) were documented during the 24-28 years of follow-up.
 
Compared with those in the lowest fifth of ultra-processed food consumption, men in the highest fifth of consumption had a 29% higher risk of developing colorectal cancer (hazard ratio for highest versus lowest fifth 1.29, 95% confidence interval 1.08 to 1.53; P for trend=0.01), and the positive association was limited to distal colon cancer (72% increased risk; hazard ratio 1.72, 1.24 to 2.37; P for trend<0.001).
 
Interestingly, these associations remained significant after further adjustment for body mass index or indicators of nutritional quality of the diet (that is, western dietary pattern or dietary quality score).
 
However, no association was observed between overall ultra-processed food consumption and risk of colorectal cancer among women.
 
It was found among subgroups of ultra-processed foods, higher consumption of meat/poultry/seafood based ready-to-eat products (hazard ratio for highest versus lowest fifth 1.44, 1.20 to 1.73; P for trend&a mp;lt;0.001) and sugar sweetened beverages (1.21, 1.01 to 1.44; P for trend=0.013) among men and ready-to-eat/heat mixed dishes among women (1.17, 1.01 to 1.36; P for trend=0.02) was associated with increased risk of colorectal cancer; yogurt and dairy based desserts were negatively associated with the risk of colorectal cancer among women (hazard ratio 0.83, 0.71 to 0.97; P for trend=0.002).
 
The study findings showed that in the three large prospective cohorts, high consumption of total ultra-processed foods in men and certain subgroups of ultra-processed foods in men and women was associated with an increased risk of colorectal cancer. Further studies are needed to better understand the potential attributes of ultra-processed foods that contribute to colorectal carcinogenesis.
 
The study findings were published in the peer reviewed British Medical Journal (BMJ).
https://www.bmj.com/content/378/bmj-2021-068921
 
The study findings clearly demonstrated that men who consumed high rates of ultra-processed foods were at higher risk for developing colorectal cancer than those who did not.
 
At present, many Americans tend to overlook the less-than-ideal nutritional aspects of ultra-processed foods for the convenience of pre-cooked and instant meals.
 
The study team hope that will change after recently discovering a link between the high consumption of ultra-processed foods and an increased risk of colorectal cancer.
 
The study findings clearly showed that men who consumed high rates of ultra-processed foods were at 29% higher risk for developing colorectal cancer which is currently the third most diagnosed cancer in the United States, ….than men who consumed much smaller amounts. They did not find the same association in women.
 
Lead author Dr Lu Wang, a postdoctoral fellow at the Friedman School of Nutrition Science and Policy at Tufts told Thailand Medical News, "We started out thinking that colorectal cancer could be the cancer most impacted by diet compared to other cancer types. Processed meats, most of which fall into the category of ultra-processed foods, are a strong risk factor for colorectal cancer. Ultra-processed foods are also high in added sugars and low in fiber, which contribute to weight gain and obesity, and obesity is an established risk factor for colorectal cancer."
 
The research analyzed responses from over 200,000 participants ie 159,907 women and 46,341 men, across three large prospective studies which assessed dietary intake and were conducted over more than 25 years. Each participant was provided with a food frequency questionnaire every four years and asked about the frequency of consumption of roughly 130 foods.
 
Study participants' intake of ultra-processed foods was then classified into quintiles, ranging in value from the lowest consumption to the highest. Those in the highest quintile were identified as being the most at risk for developing colorectal cancer. Although there was a clear link identified for men, particularly in cases of colorectal cancer in the distal colon, the study did not find an overall increased risk for women who consumed higher amounts of ultra-processed foods.
 
The research analyses revealed differences in the ways that men and women consume ultra-processed foods and the prospective associated cancer risk.
 
The study team documented 1,294 cases of colorectal cancer among men, and 1,922 cases among women out of the 206,000 participants followed for more than 25 years.
 
The study team found the strongest association between colorectal cancer and ultra-processed foods among men come from the meat, poultry, or fish-based, ready-to-eat products.
 
Dr Wang said, "These products include some processed meats like sausages, bacon, ham, and fish cakes. This is consistent with our hypothesis.”
 
The study team also found higher consumption of sugar-sweetened beverages, like soda, fruit-based beverages, and sugary milk-based beverages, is associated with an increased risk of colorectal cancer in men.
 
Not all ultra-processed foods are however equally harmful with regard to colorectal cancer risk.
 
Co-senior author Dr Fang Fang Zhang, a cancer epidemiologist and interim chair of the Division of Nutrition Epidemiology and Data Science at the Friedman School added, “We found an inverse association between ultra-processed dairy foods like yogurt and colorectal cancer risk among women.”
 
There was not a link between ultra-processed food consumption and colorectal cancer risk among women. It's possible that the composition of the ultra-processed foods consumed by women could be different than that from men.
 
Dr Zhang added, "Foods like yogurt can potentially counteract the harmful impacts of other types of ultra-processed foods in women."
 
Co-senior author Dr Mingyang Song, an assistant professor of clinical epidemiology and nutrition at the Harvard T.H. Chan School of Public Health added, "Further research will need to determine whether there is a true sex difference in the associations, or if null findings in women in this study were merely due to chance or some other uncontrolled confounding factors in women that mitigated the association."
 
Though ultra-processed foods are often associated with poor diet quality, there could be factors beyond the poor diet quality of ultra-processed foods that impact the risk of developing colorectal cancer.
 
The study team noted that the potential role of food additives in altering gut microbiota, promoting inflammation, and contaminants formed during food processing or migrated from food packaging may all promote cancer.
 
The study team had ample data to process and review all data with more than a 90% follow-up rate from each of the three studies.
 
Dr Song further added, "Cancer takes years or even decades to develop, and from our epidemiological studies, we have shown the potential latency effect ie it takes years to see an effect for certain exposure on cancer risk. Because of this lengthy process, it's important to have long-term exposure to data to better evaluate cancer risk.
 
The cohorts included in the study were:
-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.
 
Upon an exclusionary process for past diagnoses or incomplete surveys, the study team were left with prospective data from 159,907 women from both NHS studies and 46,341 men.
 
The researchers adjusted for potential confounding factors such as race, family history of cancer, history of endoscopy, physical activity hours per week, smoking status, total alcohol intake and total caloric intake, regular aspirin use, and menopausal status.
 
The study team noted since the participants in these studies all worked in the healthcare field, the findings for this population may not be the same as they would be for the general population, since the participants may be more inclined to eat healthier and lean away from ultra-processed foods. The data may also be skewed because processing has changed over the past two decades.
 
Dr Zhang reassured, "But we are comparing within that population those who consume higher amounts versus lower amounts. So those comparisons are valid."
 
Dr Wang and Dr Zhang previously published a study that identified a trend in increased ultra-processed food consumption in U.S. children and adolescents.
 
Both the previous and current study underscores the idea that many different groups of people may be dependent on ultra-processed foods in their daily diets.
 
Dr Zhang, who is also a member of the Tufts Institute for Global Obesity Research added, "Much of the dependence on these foods can come down to factors like food access and convenience. Chemically processing foods can aid in extending shelf life, but many processed foods are less healthy than unprocessed alternatives. We need to make consumers aware of the risks associated with consuming unhealthy foods in quantity and make the healthier options easier to choose instead."
 
Dr Wang knows that change won't happen overnight, and hopes that this study, among others, will contribute to changes in dietary regulations and recommendations.
 
Dr Wang said, "Long-term change will require a multi-step approach. Researchers continue to examine how nutrition-related policies, dietary recommendations, and recipe and formula changes, coupled with other healthy lifestyle habits, can improve overall health and reduce cancer burden. It will be important for us to continue to study the link between cancer and diet, as well as the potential interventions to improve outcomes.”
 
In the meanwhile, men should try to avoid consuming ultra-processed foods especially cured meats, sugar-sweetened beverages, like soda, fruit-based beverages, and sugary milk-based beverages.
 
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