Findings from two studies recently published in The BMJ suggest that frequent consumption of ultra-processed foods (UPFs) was associated with a higher risk of colorectal cancer, all-cause mortality, and cardiovascular mortality, Zaina Hamza writes for MedPage Today.

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Details and key findings

In the first study, researchers analyzed three prospective cohort studies. They followed 46,341 men from the Health Professionals Follow-up Study from 1986 to 2014, 67,425 women from the Nurses' Health Study I from 1986 to 2014, and 92,482 women from the Nurses' Health Study II from 1991 to 2015. They used the NOVA classification system to evaluate UPF intake.

During 24 to 28 years of follow-up, a total of 3,216 cases of colorectal cancer were reported, including 1,294 in men and 1,922 in women. According to Fang Zhang of Tufts University and colleagues, men who consumed the most UPFs had a 29% higher risk of developing colorectal cancer than those who consumed the least. The researchers found an even stronger association between UPF consumption and distal colon cancer.

In particular, a higher consumption of sugar-sweetened beverages and meat, poultry, or seafood-based ready-to-eat products was associated with an increased risk of colorectal cancer in men. Meanwhile, a higher consumption of ready-to-eat or heat mixed dishes were linked to an increased risk for women. Notably, dairy-based desserts and yogurt were tied to a 17% lower risk of colorectal cancer among women.

According to the researchers, the associations were statistically significant after they adjusted for body mass index and nutritional quality indicators. However, they did not find an overall association between UPF intake and colorectal cancer among women.

In the second study, Marialaura Bonaccio of IRCCS Neuromed in Pozzilli, Italy, and colleagues, analyzed an Italian prospective study, which included data on 22,895 participants in Molise, Italy from March 2005 to December 2010. On average, participants were age 55 years old, and 52% were women.

To evaluate UPF intake, they used the Food Standards Agency Nutrient Profiling System (FSAm-NPS) dietary index. They used the NOVA classification system to assess mortality.

Over a median follow-up of 12.2 years, a total of 2,205 participants died.

Among adults with the highest intake of UPFs, an adjusted multivariable analysis found a higher risk of all-cause mortality and cardiovascular mortality than adults with the lowest intake. When looking at only those who fell within the two highest categories of ultra-processed food intake, the associations remained for both all-cause mortality and cardiovascular mortality.

According to their findings, the relationship between the FSAm-NPS dietary index and all-cause mortality was reduced by 22.3%. In addition, there was a 15.4% reduction in the relationship between the relationship between the FSAm-NPS dietary index and cardiovascular mortality. Notably, mortality risks associated with high UPF intake were not changed.

"So the problem with ultra-processed products has been suggested to be simply their poor nutrient profiles," said Carlos Monteiro and Geoffrey Cannon of the University of São Paulo.

Commentary

In an editorial accompanying the second study, Monteiro and Cannon noted that "the overall positive solution includes making supplies of fresh and minimally processed foods ... available, attractive, and affordable. And sustaining national initiatives to promote and support freshly prepared meals made with fresh and minimally processed foods, using small amounts of processed culinary ingredients and processed foods."

"Enacted, this will promote public health. It will also nourish families, society, economies, and the environment," they added. (Hamza, MedPage Today, 8/31)