A 30-year American study links ultra-processed foods to an increased risk of premature death

Higher consumption of most ultra-processed foods is linked to a slightly higher risk of death, with ready-to-eat meat, poultry and seafood products, sugary drinks, dairy-based desserts and highly processed breakfast foods which show the strongest associations. finds an American study of 30 years a The BMJ today.

The researchers say that not all ultra-processed food products should be universally restricted, but that their findings “provide support for limiting consumption of certain types of ultra-processed foods for long-term health.”

Ultra-processed foods include baked goods and packaged snacks, fizzy drinks, sugary cereals, and ready-to-eat or reheat foods. They often contain colors, emulsifiers, flavors and other additives and are usually high in energy, added sugar, saturated fat and salt, but lack vitamins and fibre.

Growing evidence links ultra-processed foods to an increased risk of obesity, heart disease, diabetes and bowel cancer, but few long-term studies have examined the links to all-cause and cause-specific deaths, particularly from cancer.

To address this knowledge gap, researchers tracked the long-term health of 74,563 registered nurses from 11 US states in the Nurses’ Health Study (1984-2018) and 39,501 professionals in the men’s health from the 50 states of the United States in the follow-up of health professionals. Study (1986-2018) with no history of cancer, cardiovascular disease, or diabetes at study enrollment.

Every two years, participants provided information about their health and lifestyle habits, and every four years they completed a detailed food questionnaire. Overall diet quality was also assessed using the Alternative Healthy Eating Index-2010 (AHEI) score.

During an average follow-up period of 34 years, the researchers identified 48,193 deaths, including 13,557 deaths from cancer, 11,416 deaths from cardiovascular disease, 3,926 deaths from respiratory disease and 6,343 deaths from neurodegenerative diseases.

Compared with participants in the lowest quartile of ultra-processed food intake (average 3 servings per day), those in the highest quartile (average 7 servings per day) had a 4% higher risk of total death and a 9 % higher risk of other deaths, including an 8% higher risk of neurodegenerative deaths.

No associations were found with deaths from cardiovascular disease, cancer, or respiratory disease.

In absolute terms, the death rate from any cause among participants in the lowest and highest quartile of ultra-processed food intake was 1,472 and 1,536 per 100,000 person-years, respectively.

The association between ultra-processed food intake and death varied by specific food group, with prepared meat, poultry and seafood products showing the strongest and most consistent associations, followed by sugar-sweetened beverages sugar and artificially sweetened beverages. dairy-based desserts and ultra-processed breakfast foods.

The association was less pronounced after overall diet quality was taken into account, suggesting that diet quality has a stronger influence on long-term health than consumption of ultra-processed foods, the authors note .

This is an observational study, so no firm conclusions can be drawn about cause and effect, and the authors note that the classification system for ultra-processed foods does not capture the full complexity of food processing, which leading to possible misclassification. In addition, participants were healthcare professionals and predominantly white, limiting the generalizability of the findings.

However, this was a large study with a long follow-up, using detailed, validated and repeated measures, and the results were similar after further analysis, providing greater confidence in the conclusions.

The researchers stress that not all ultra-processed foods should be universally restricted and say that oversimplification should be avoided when formulating dietary recommendations.

But they conclude: “The findings provide support for limiting the consumption of certain types of ultra-processed foods for long-term health,” adding that “future studies are warranted to improve the classification of ultra-processed foods and confirm our findings in other populations”. “

In a linked editorial, New Zealand researchers note that recommendations to avoid ultra-processed foods may also give the impression that non-ultra-processed foods, such as red meat, can be eaten frequently.

They argue that the debate over the ultra-processed concept should not delay food policies that improve health, such as restrictions on the marketing of unhealthy foods to children, warning labels on nutritionally poor food products, and taxes on sugary drinks

“Our focus should be to advocate for greater global adoption of these and more ambitious interventions and increase safeguards to prevent policies from being influenced by multinational food companies with vested interests that do not align with public health goals or environmental”, they conclude.