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Eating ultra-processed foods for more than 20% of your daily calorie intake each day can put you on the road to cognitive decline, a new study has found.
We all know that eating ultra-processed foods that make our lives easier—like prepackaged soups, sauces, frozen pizzas, and ready-to-eat meals—is not good for our health. Nor is ingesting all the comfort foods we love so much: hot dogs, sausages, burgers, fries, sodas, cookies, cakes, candy, donuts, and ice cream, to name a few.
Studies have found that they can increase the risk of obesity, heart and circulatory problems, diabetes and cancer. They can even shorten our lives.
Now, a new study has revealed that eating more ultra-processed foods may contribute to overall cognitive decline, including areas of the brain involved in executive functioning – the ability to process information and make decisions.
In fact, men and women who ate the most ultra-processed foods had a 28% faster rate of global cognitive decline and a 25% faster rate of decline in executive function than people who ate the least amount too processed food, the study found.
“Although they need further study and replication, the new results are quite compelling and highlight the critical role of proper nutrition in preserving and promoting brain health and reducing the risk of brain diseases as we age,” said Rudy Tanzi, professor of neurology at Harvard Medical School and director of the Division of Genetics and Aging Research at Massachusetts General Hospital in Boston. He did not participate in the research.
Tanzi, who wrote about ultra-processed foods in his book The Healing Self: A Revolutionary New Plan to Recharge Your Immune System and Maintain Good Health for Life, said the key problem with ultra-processed foods is that “they tend to be very high in sugar, salt and fat, all of which promote systemic inflammation, perhaps the biggest threat to healthy aging in the body and brain.
“Meanwhile, because they’re convenient as fast food, they also replace the consumption of high-fiber foods that are important for maintaining the health and balance of the trillions of bacteria in your gut microbiome,” he added, “which is particularly important for brain health and reducing the risk of age-related brain diseases such as Alzheimer’s disease.
The study, presented Monday at the 2022 Alzheimer’s Association International Conference in San Diego, followed more than 10,000 Brazilians for up to 10 years. Just over half of the survey participants were female, white or college-educated, while the average age was 51.
Cognitive testing, which included immediate and delayed word recall, word recognition, and verbal fluency, was performed at the beginning and end of the study, and participants were asked about their diet.
“In Brazil, ultra-processed foods make up 25% to 30% of total calorie intake. We have McDonald’s, Burger King and we eat a lot of chocolate and white bread. Unfortunately, it’s not very different from many other Western countries,” said co-author Dr. Claudia Suemoto, an assistant professor in the Geriatrics Department at the University of São Paulo’s Faculty of Medicine.
“Fifty-eight percent of the calories consumed by United States citizens, 56.8 percent of the calories consumed by British citizens, and 48 percent of the calories consumed by Canadians come from ultra-processed foods,” Suemoto said.
Ultra-processed foods are defined as “industrial formulations of nutrients (oils, fats, sugars, starches, and protein isolates) that contain little or no whole foods and typically include flavors, colors, emulsifiers, and other cosmetic additives,” according to the study.
“People who consumed 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 than people who ate less than 20%.” , said study co-author Natalia Gonsalves, a researcher in the Department of Pathology at the Faculty of Medicine of the University of São Paulo.
For a person eating 2,000 calories a day, 20% would equate to 400 or more calories – a small order of fries, by comparison and a regular McDonalds cheeseburger contains total 530 calories.
Those in the study who ate the most ultra-processed foods were “more likely to be younger, female, white, with higher education and income, and more likely to have never smoked and less likely to are current alcohol consumers,” the study found.
“People need to know that they need to cook more and prepare their food from scratch. I know. We say we don’t have time, but it really doesn’t take us that long,” Suemoto said.
“And it’s worth it because you’ll protect your heart and protect your brain from dementia or Alzheimer’s,” she added. “That’s the take home message: Stop buying things that are super processed.”