A higher proportion of ultraprocessed foods in a diet was linked with higher risk of type 2 diabetes (T2D), researchers reported.
In an analysis of daily nutritional data of French adults, consuming more -- foods with additives that undergo several physical or chemical processing -- increased the risk for new onset diabetes, reported Bernard Srour, PharmD, MPH, PhD, of the Epidemiology and Statistics Research Center-University of Paris, and colleagues in .
This increased risk remained elevated even after adjustment for other metabolic comorbidities, including dyslipidemia and hypertension, as well as various markers representing the nutritional quality of one's diet measured by the Food Standard Agency nutrient profiling system dietary index (HR 1.13, 95% CI 1.03-1.23). For example, lower quality diets were marked by higher sodium, sugar, and red meat intake, with lower intake of fiber, whole grains, and vegetables.
For every 10% more ultraprocessed foods that made up a person's diet, there was a 15% increased risk for developing diabetes (HR 1.15, 95% CI 1.06-1.25).
On the other hand, a diet comprised of more unprocessed or minimally processed foods was tied to a small, but significantly, lower risk for diabetes (HR 0.91 for a 10-point increment, 95% CI 0.84-0.98).
After adjusting for unprocessed or minimally processed food intake, every additional 100 grams of ultraprocessed food intake was associated with a 5% bump in the risk for diabetes (HR 1.05, 95% CI 1.02-1.08).
There may be several explanations for this association, Srour's group wrote: "[Ultraprocessed foods] usually have a lower nutritional quality because they are on average richer in sodium, energy, fat, sugar, and poorer in fiber and often exhibit a higher glycemic index."
"Many food groups, mostly ultraprocessed (eg, processed meat, and sugary sweetened beverages) are recognized T2D risk factors," they continued.
Their prospective cohort study included nutritional data on over 100,000 participants from the French NutriNet-Santé cohort, nearly 80% of whom were women. From 2009 to 2019, participants completed several questionnaires based on sociodemographics, lifestyle characteristics, physical activity, general health, and nutrition. Dietary data was collected based on self-reported 24-hour dietary recall, with each participant completing a series of at least three nonconsecutive records.
The dietary records inquired about intake on over 3,500 food items, which were subsequently broken down into one of four categories: unprocessed or minimally processed, culinary ingredients, processed foods, or ultraprocessed foods. Ultraprocessed foods were considered foods that underwent several rounds of processing, and typically contained food additives such as refined sugars, hydrogenated oils, emulsifiers, thickening agents, and colorants. These were categorized according to their degree of processing by the classification system.
During the median 6-year follow-up period, there were 821 total incident diabetes cases noted.
When identifying these foods, the researchers pointed out that the presence of additives are the cornerstone of an "ultraprocessed" food.
"Most [additives] are likely to be neutral for long-term health and some may even be beneficial (eg, antioxidants), but recent concerns emerged mainly from in-vitro/in-vivo models for several compounds commonly used in thousands of foods," Srour's group explained.
"For instance, , a thickening and stabilizing agent, used in more than 5500 products in France and pertaining to the top-20 used additives in France, might contribute to the development of diabetes by impairing glucose tolerance, increasing insulin resistance, and inhibiting insulin signaling in human HepG2 cells."
Although the current research, and previous data, on the subject cannot establish a causal relationship between processed foods and diabetes risk, the researchers still advised that people limit their amount of ultraprocessed food intake as a "precautionary principle."
Disclosures
The study was supported by Ministère de la Santé, Santé Publique France, Institut National de la Santé et de la Recherche Médicale, Institut National de la Recherche Agronomique, Conservatoire National des Arts et Métiers, and Université Paris 13.
Srour and co-authors disclosed no relevant relationships with industry.
Primary Source
JAMA Internal Medicine
Srour B, et al "Ultraprocessed food consumption and risk of type 2 diabetes among participants of the NutriNet-Santé prospective cohort" JAMA Intern Med 2019; DOI: 10.1001/jamainternmed.2019.5942.