Harm from processed foods goes beyond what it does to your body. New research shows that it also adversely affects your brain and can even lead to memory loss.

Four weeks on a diet of highly processed food led to a strong inflammatory response in the brains of aging rats that was accompanied by behavioral signs of memory loss, a new study has found. Researchers also found that supplementing the processed diet with the omega-3 fatty acid DHA prevented memory problems and reduced the inflammatory effects almost entirely in older rats.

The Research Study on Processed Foods

• The study diet mimicked ready-to-eat human foods that are often packaged for long shelf lives, such as potato chips and other snacks, frozen entrees like pasta dishes and pizzas, and deli meats containing preservatives.

• The research team randomly assigned 3-month-old and 24-month-old male rats to their normal chow (32% calories from protein, 54% from wheat-based complex carbs and 14% from fat), a highly processed diet (19.6% of calories from protein, 63.3% from refined carbs — cornstarch, maltodextrin and sucrose — and 17.1% from fat), or the same processed diet supplemented with DHA.

The older rats on the processed diet also showed signs of memory loss in behavioral experiments that weren’t evident in the young rats. They forgot having spent time in an unfamiliar space within a few days, a sign of problems with contextual memory in the hippocampus, and did not display anticipatory fear behavior to a danger cue, which suggested there were abnormalities in the amygdala.

Harm from Processed Foods May Be Mitigated with Omega-3s

Researchers don’t know the exact dosage of DHA — or precise calories and nutrients — taken in by the animals, which all had unlimited access to food. Both age groups gained a significant amount of weight on the processed diet, with old animals gaining significantly more than the young animals. DHA supplementation had no preventive effect on weight gain associated with eating highly processed foods.

That was a key finding: Barrientos cautioned against interpreting the results as a license for consumers to feast on processed foods as long as they take a DHA supplement. A better bet to prevent multiple negative effects of highly refined foods would be focusing on overall diet improvement, she said.

“These are the types of diets that are advertised as being low in fat, but they’re highly processed. They have no fiber and have refined carbohydrates that are also known as low-quality carbohydrates,” she said. “Folks who are used to looking at nutritional information need to pay attention to the fiber and quality of carbohydrates. This study really shows those things are important.”

Recommendations from the Researchers

• Highly processed diets are also associated with obesity and type 2 diabetes, suggesting older consumers might want to scale back on convenience foods and add foods rich in DHA, such as salmon, to their diets.
• “The fact we’re seeing these effects so quickly is a little bit alarming,” said senior study author Ruth Barrientos, an investigator in The Ohio State University Institute for Behavioral Medicine Research and associate professor of psychiatry and behavioral health.

• These findings indicate that consumption of a processed diet can produce significant and abrupt memory deficits, which may lead Alzheimer’s disease. either prevent or slow that progression.”

Click here to learn more about harm from processed foods.