Recent research has unveiled alarming connections between the consumption of ultra-processed foods and an increased risk of cognitive decline and stroke.
Ultra-processed foods, such as prepackaged meals, deli meats, potato chips, sodas, and sweetened breakfast cereals, have become a staple in modern diets. However, their convenience may come at a significant cost to our brain health.
In an extensive study published in Neurology, scientists analyzed data spanning approximately ten years, focusing on the eating habits, cognitive function, and stroke incidence of about 30,000 adults, most of whom were in their mid-sixties at the study’s onset.
Importantly, none of the participants had a history of cognitive impairment when the study began, making the findings particularly concerning. By the end of the follow-up period, 1,108 participants had suffered a stroke, and 768 had developed cognitive impairment.
The results indicated that a diet high in ultra-processed foods was linked to an 8% greater risk of stroke and a 12% higher risk of accelerated cognitive decline. Conversely, those who consumed the most unprocessed or minimally processed foods enjoyed a 9% lower risk of stroke. These findings underscore the profound impact that diet can have on brain health.
“Our study provides a reason to be mindful of the food we eat,” says the senior study author, W. Taylor Kimberly, MD, PhD, an associate professor at Harvard Medical School and the chief of neurocritical care at Massachusetts General Hospital in Boston. “Not only should we aim to increase the amount of healthy foods, such as leafy greens, nuts, and fish-based protein, but we should also aim to reduce the amount of prepackaged foods and sweet and salty snacks.”
Small Changes in Ultra-Processed Food Have Significant Impact
One of the study’s most compelling findings is the significant difference that even small dietary changes can make. The research showed that each 10% increase in the consumption of unprocessed and minimally processed foods was associated with a 12% reduction in the risk of accelerated cognitive decline.
On the flip side, each 10% increase in the intake of ultra-processed foods was linked to a 16% higher risk of cognitive decline.
These findings were consistent even among participants who followed diets known to support brain health, such as the Mediterranean, DASH, or MIND diets. All of these diets emphasize plant-based meals, fruits, vegetables, whole grains, beans, and nuts, while limiting ultra-processed foods, red meat, and sugary foods and drinks. This suggests that while following a healthy diet is important, paying attention to the level of food processing is also crucial.
Understanding Ultra-Processed Foods
To comprehend the study’s implications, it is essential to understand what constitutes ultra-processed foods. Generally, ultra-processed foods are those that have undergone extensive processing and are typically industrial products. They are made primarily from substances extracted from oils, fats, sugars, starches, and proteins, or synthesized in laboratories. These foods often contain few, if any, natural ingredients.
For example, consider potatoes. A whole potato, found in the produce aisle, is unprocessed, while canned potatoes are minimally processed. However, potato chips and frozen hash browns fall into the ultra-processed category due to the extensive processing and added ingredients involved in their production.
The Potential Risks of Ultra-Processed Foods
The study did not specifically aim to prove that ultra-processed foods directly cause cognitive decline or stroke, but it did establish a clear association between high consumption of these foods and an increased risk of these conditions. Researchers have proposed several theories to explain why ultra-processed foods might be harmful to brain health.
One possibility is that the chemicals and other substances added to ultra-processed foods to extend their shelf life could negatively impact cognitive function.
“There are often chemicals and other substances added to ultra-processed foods that are different from what we would have eaten in traditionally prepared foods, and some of those may have brain health risks,” says Glen Finney, MD, a professor and the director of the memory and cognition program at Geisinger Health in Wilkes-Barre, Pennsylvania, who was not involved in the study. “It’s still something that we need to know more about.”
In addition to potentially harmful additives, ultra-processed foods are typically high in unhealthy ingredients such as sugar, salt, and fat. These components can trigger inflammation, which may lead to vascular dysfunction and, consequently, impair cognitive functions.
“These foods contain added ingredients like sugar, salt, fat, artificial colors, and preservatives, as well as substances extracted from foods such as fats and starches,” explains Yu Chen, MPH, PhD, a professor of epidemiology at New York University Grossman School of Medicine in Manhattan, who was also not involved in the study.
“Components like fat can trigger inflammation, possibly leading to vascular dysfunction and impacting cognitive functions,” she added.
Recommendations for a Brain-Healthy Diet
Given the potential risks associated with ultra-processed foods, experts recommend minimizing their consumption to promote long-term brain health.
Andrew Budson, MD, a professor of neurology at Boston University and coauthor of Seven Steps to Managing Your Aging Memory, emphasizes the importance of prioritizing while foods in our diets.
“Don’t eat processed foods, which can include chips, industrial breads and pastries, packaged sweets and candy, sugar and diet sodas, instant noodles and soups, ready-to-eat meals and frozen dinners, and processed meats such as hot dogs and bologna,” says Dr. Budson, who wasn’t involved in the new study.
“Simply eat unprocessed or minimally processed foods, which — when combined with a healthy Mediterranean menu of foods — include fish, olive oil, avocados, whole fruits and vegetables, nuts and beans, and whole grains,” he adds.
The findings of this study highlight the significant impact that diet can have on brain health, particularly as we age. While ultra-processed foods are convenient and often tasty, their potential risks to cognitive function and overall health are becoming increasingly apparent.
By making mindful dietary choices, such as incorporating more whole foods and reducing the intake of ultra-processed products, we can take meaningful steps toward protecting our brains and promoting long-term health.
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