We all know that eating ultra-processed foods that make our lives easier — like prepackaged soups, sauces, frozen pizza, and ready meals — is not good for our health. Also, not gorging on all the stimulants we love so much: hot dogs, sausage, burgers, french fries, sodas, cookies, cakes, candy, donuts, and ice cream, to name a few.
Now a new study has shown that eating more ultra-processed foods may contribute to overall cognitive decline, including areas of the brain involved in executive function — the ability to process information and make decisions.
In fact, men and women who ate the most processed foods had a 28% faster rate of global cognitive decline and a 25% faster rate of executive function decline compared to people who ate the least amount of overly processed foods took, the study found out.
“Although further study and replication is needed, the new findings are quite compelling and emphasize the crucial role of proper nutrition in maintaining and promoting brain health and reducing the risk of brain disease as we age,” said Rudy Tanzi, professor of Neurology at Harvard Medical School and director of the Genetics and Aging Research Unit at Massachusetts General Hospital in Boston. He was not involved in the study.
Tanzi, who wrote about ultraprocessed foods in his book The Healing Self: A Revolutionary New Plan to Supercharge Your Immunity and Stay Well for Life, said the main problem with ultraprocessed foods is that “they’re usually very high in sugar and salt and fat, all of which promote systemic inflammation, perhaps the greatest threat to healthy aging in the body and brain.
“Meanwhile, because they’re good for a quick meal, they also replace eating foods high in plant fiber, which are important for maintaining the health and balance of the trillions of bacteria in your gut microbiome,” he added, “what especially important is important for brain health and reducing the risk of age-related brain diseases like Alzheimer’s disease.”
It’s not a lot of calories
The study, presented Monday at the Alzheimer’s Association 2022 international conference in San Diego, followed over 10,000 Brazilians for up to 10 years. Just over half of the study participants were women, white or college graduates, while the median age was 51 years.
Cognitive tests that included immediate and delayed word recall, word recognition, and verbal fluency were administered at the beginning and end of the study, and participants were asked about their diet.
“In Brazil, ultra-processed foods account for 25 to 30 percent of total calorie intake. We have McDonald’s, Burger King and we eat a lot of chocolate and white bread. Unfortunately, that’s not much different than in many other western countries,” he told co-author Dr. Claudia Suemoto, Assistant Professor in the Department of Geriatrics at the University of São Paulo Faculty of Medicine.
“Fifty-eight percent of the calories consumed by US citizens, 56.8 percent of British citizens and 48 percent of Canadians come from ultra-processed foods,” Suemoto said.
Ultra-processed foods are defined, according to the study, as “industrial formulations of food substances (oils, fats, sugars, starches, and protein isolates) that contain little or no whole foods and typically contain flavorings, colors, emulsifiers, and other cosmetic additives.” .
“People who ate more than 20% of their daily calories from processed foods had a 28% faster decline in global cognition and a 25% faster decline in executive function compared to people who ate less than 20% took,” said study co-author Natalia Gonçalves, a researcher in the Department of Pathology at the Medical Faculty of the University of São Paulo.
For a person consuming 2,000 calories a day, 20% equates to 400 or more calories—for comparison, a small serving of fries and regular McDonald’s cheeseburger contains a total of 530 calories.
Those in the study who ate the most processed foods were “more likely to be younger, female, white, had higher education and income, were more likely never to have smoked, and were less likely to be current alcohol users,” the study noted study firm .
“People need to know that they should cook more and prepare their own food from scratch. I know. We say we don’t have time, but it really doesn’t take that long,” Suemoto said.
“And it’s worth it because you’re protecting your heart and your brain from dementia or Alzheimer’s,” she added. “That’s the take-home message: stop buying things that are super-crafted.”