Diets high in industrially produced foods impair muscle quality, associated with knee osteoarthritis

Dec. 4 (UPI) -- Consuming more packaged breakfast cereals and snacks, margarine and spreads, hot dogs, sodas and energy beverages, candy and desserts, mass-produced bakery products and other ultra-processed food is linked to higher levels of fat in thigh muscles, a new study found.

The research looking at the muscle quality of 666 obese men and women with an average age of 60, which is to be presented Wednesday to the Radiological Society of North America's annual meeting in Chicago, found the association regardless of calorie count or how physically active study subjects were, RSNA said in a news release.

Using MRI scans from a National Institutes of Health osteoarthritis prevention program, the team found the more ultra-processed foods people consumed, the more intramuscular fat they had in their thigh muscles, which as well as making muscles weaker is a potential indicator of knee osteoarthritis down the line.

Bilateral thigh MR images and magnified frames of areas inside knee extensor muscles of obese women whose diets were more than two-thirds industrially processed food found "abundant fatty streaks," almost double the levels found in women for whom ultra-processed foods made up a little more than a third of their diet.

"Research from our group and others has previously shown that quantitative and functional decline in thigh muscles is potentially associated with onset and progression of knee osteoarthritis," said lead author Dr. Zehra Akkaya, researcher and former Fulbright Scholar in the Department of Radiology and Biomedical Imaging at the University of California-San Francisco.

"On MRI images, this decline can be seen as fatty degeneration of the muscle, where streaks of fat replace muscle fibers," Akkaya said.

"In an adult population at risk for but without knee or hip osteoarthritis, consuming ultra-processed foods is linked to increased fat within the thigh muscles. These findings held true regardless of dietary energy content, BMI, sociodemographic factors or physical activity levels."

The increasing prevalence in modern diets of highly processed, artificially flavored, colored or chemically altered ingredients in place of minimally processed ingredients provides the benefit of long shelf life and convenience but the combination of sugar, fat, salt and carbohydrates that makes them so appealing makes it hard to know when to stop eating because they hijack brain's reward system.

With osteoarthritis, the largest contributor to non-cancer related health care costs in the United States and globally, according to Akkaya, the strong link to obesity and unhealthy choices provides a route forward via adopting healthier lifestyles and managing disease.

Prevention of obesity through a healthy, balanced diet and adequate exercise is already the accepted first stop in the management of knee osteoarthritis.

Akkaya said he believed the study, the first of its kind to look at how ultra-processed food consumption impacts muscle composition, provided valuable insight into the effect of diet on muscle health.

"Understanding this relationship could have important clinical implications, as it offers a new perspective on how diet quality affects musculoskeletal health," Akkaya said.