People who frequently eat ultra-processed foods such as snacks and instant meals showed a higher risk of cardiovascular disease, cancer and obesity, as well as diabetes and death, according to a new analysis.
Health Risks Rise With Intake
An international research team including Xiao Liu of Duke-NUS Medical School in Singapore published the findings on the 23rd in the journal Family Medicine and Community Health (FMCH).
The researchers pooled data on 8,819,894 adults from 51 prospective cohort studies to examine the relationship between ultra-processed food intake and health risks. The analysis found a dose-response relationship, in which disease risk rose along with consumption.
The group that ate the most ultra-processed foods had a 24% higher risk of cardiovascular events than the group that ate the least. Cancer risk was 12% higher, obesity and overweight risk 23% higher, and metabolic syndrome and diabetes risk 24% higher. Depression and anxiety were 27% higher, digestive disorders 31% higher, and all-cause mortality risk 18% higher.
A similar pattern emerged when intake was compared in increments of 100 grams a day. The risk of cardiovascular events rose 14%, cancer 4%, all-cause mortality 3% and metabolic syndrome and diabetes 2%.
The analysis covered 16 studies from the Americas, 25 from Europe, eight from Asia and two from Oceania. Participants averaged 23.9 to 77 years of age, and follow-up periods ranged from two to 32 years.
Additives and Processing Methods Also Warrant Study
Ultra-processed foods are products that go through multiple industrial processes so they can be eaten without separate cooking or after simply heating. They are typically high in energy density, sugar and sodium, while relatively low in dietary fiber, protein, vitamins and minerals.
The researchers also pointed to the possibility that a so-called cocktail effect, in which multiple additives act at the same time, affects health. Laboratory studies have suggested that the physical properties of foods altered during ultra-processing may influence gut microbiota and promote inflammation or insulin resistance.
The findings should not be taken to mean that ultra-processed foods directly cause disease or death, the researchers said. The study is an analysis pooling existing observational research, intake was based on participants' self-reporting, and the classification of ultra-processed foods and methods of dietary assessment differed from study to study.
Future research needs to classify ultra-processed foods more precisely by reflecting not only ingredients and components but also added sugar, dietary fiber, sodium and the quality of fats, and to determine the risks and appropriate intake levels for each type of food, according to the analysis.
