Americans love ultra-processed food! Things that come in a box or bag take up a lot of shelf space in our supermarkets and convenience stores. Think: candy, crackers, Doritos, Oreos, and Fritos, not to mention potato chips. These treats also represent a high proportion of calories in our diet. Two new studies in The BMJ show the dangers of eating too many ultra-processed foods.
Men who eat ultra-processed foods are more prone to colorectal cancer:
One analysis used data from three long-term cohort studies of health professionals (BMJAugust 31, 2022). (You may recognize them as the Follow-up study of health professionalsthe Nurses Health Study and the Nurses Health Study 2.) More than 46,000 male health professionals and nearly 160,000 nurses completed detailed dietary questionnaires every four years and provided health information.
The scientists followed these conscientious subjects for an average of about 25 years. The men who ate the most ultra-processed foods had a 29 percent greater chance of developing colorectal cancer during that time. Highly processed meat, poultry or seafood products and sugary drinks were particular culprits for these men. Maybe beef jerky and chicken nuggets should be limited to very occasional snacks.
Interestingly, the researchers did not detect an increased risk among women who ate the most ultra-processed foods. However, they did note a trend toward higher cancer risk among women who ate more ready-to-heat or ready-to-eat foods. The scientists needed to make statistical adjustments for the fact that both men and women who ate more junk food were also likely to be smokers and less likely to exercise regularly.
Although the researchers are cautious about the conclusions they draw, they note:
“Such findings support the World Cancer Research Fund/American Institute for Cancer Research recommendation to limit ‘fast food’ intake for primary cancer prevention.”
Italians also do poorly with junk food:
A second publication looked at the diets of nearly 23,000 Italians over 14 years (BMJAugust 31, 2022). (This was another large prospective study called moli sani.) People who ate the most ultra-processed foods were 19 percent more likely to die during that time. Their risk of dying from a heart attack or other cardiovascular cause was actually 32 percent higher than that of people who ate the fewest processed foods.
Researchers analyzing these data note
“A significant proportion of the increased mortality risk associated with a high intake of nutrient-poor foods is explained by a high degree of food processing.”
Because both are observational studies, they cannot establish cause and effect. However, an editorial in the same issue (BMJAugust 31, 2022) argues that governments should make fresh and minimally processed foods accessible and affordable to promote public health. With a lot of frequency public policies designed to make food cheaper does not take quality into account.
