Too many daily calories from highly processed foods like lunch meats, frozen dinners, and packaged cookies may speed up cognitive decline, a new study suggests.
In the study, researchers examined the diets and cognitive function test results of more than 8,000 adults in Brazil. At the start of the study, participants consumed an average of about 2,850 calories a day. About 28 percent of their daily calories came from highly processed foods. After about nine years of follow-up, cognitive test scores for memory and executive function declined the most for participants who ate the most highly processed foods, according to preliminary study results presented at the Alzheimer’s Association International Conference held July 31–August 4 in San Diego.
“There is growing evidence that what we eat can impact our brains as we age, and many studies suggest it is best for our brain to eat a heart-healthy, balanced diet low in processed foods and high in whole, nutritional foods like vegetables and fruits,” says Percy Griffin, PhD, the director of scientific engagement at the Alzheimer’s Association.
“It’s troubling but not surprising to see new data suggesting these foods can significantly accelerate cognitive decline,” says Dr. Griffin, who wasn’t involved in the new study.
According to Harvard Health Publishing, highly processed foods tend to be chock-full of added sugar, salt, fat, and artificial preservatives. During manufacturing, many nutrients found in unprocessed whole foods get altered or removed, leaving products that aren’t as nutritious.
Whole foods and minimally processed foods have fewer ingredients on the label, or no label at all, according to Harvard Health. These are mostly found in the produce aisle — like ears of corn or sacks of potatoes. Canned corn or baked potatoes are processed during canning or cooking — but not so much that these products are considered highly processed. Their highly processed counterparts are corn chips and french fries.
The new study results haven’t been published in a medical journal or independently reviewed. Beyond this, a drawback of the study is that results from Brazilians may not be generalizable to people in other countries. Rice and beans are mealtime staples in Brazil, according to a study in Nutrients from May 2020, along with side servings of meat, vegetables, dairy, bread, and fruits. A typical Western or U.S. diet, per an article in the November–December Missouri Medicine, is full of sugars, fats, red and processed meats, and refined grains.
