A study suggests that ultra-processed meals may increase our risk of cognitive difficulties and strokes, adding to the growing body of data that our diet has a substantial impact on brain function.
Extensive research has linked ultra-processed meals to an increased risk of many ailments, including heart disease, diabetes, colon cancer, and obesity.
A new study from Massachusetts General Hospital found a correlation between these diets and brain health.
"Multiple independent studies have shown associations between ultra-processed foods and significant health outcomes," stated study author and Harvard neurology professor W. Taylor Kimberly in an interview with Newsweek.
"Our research contributes to this body of work by demonstrating that ultra-processed foods are associated with two critical factors in impaired brain function—stroke and cognitive impairment," he continued. "It's crucial to consider not only the types of foods we consume but also how they are processed."
Published in the journal Neurology, the study analyzed data from 30,239 participants aged 45 and older, tracked over an average of 11 years.
Participants completed questionnaires detailing their dietary habits, allowing the research team to calculate their average daily intake of ultra-processed foods.
Among these people, 14,175 were tested for evidence of cognitive loss, while 20,243 were assessed for stroke risk.
At the start of the trial, none of the participants had a history of cognitive decline or stroke. In the end, 768 people were diagnosed with cognitive impairment, while 1,108 had a stroke.
Adjusting for age, gender, high blood pressure, and other established dementia risk factors, the team discovered that a 10% rise in ultra-processed food consumption was associated with a 16% higher risk of cognitive impairment.
Consuming unprocessed or little processed foods, on the other hand, was associated with a 12 percent lower risk of cognitive impairment.
Similarly, those who consumed more ultra-processed foods had an 8% higher risk of stroke, but those who consumed fewer processed foods had a 9% reduced risk.
This effect was most prominent among Black participants, who had a 15% elevated stroke risk due to ultra-processed food consumption.
"Our findings show that the degree of food processing plays an important role in overall brain health," Kimberly stated.
More research is needed to confirm these findings and determine which food or processing components are most responsible for these impacts.... These findings are associations, thus a randomized trial will be needed to determine how changing our diet affects the risk of these health problems."
Although this study did not explore the causal mechanisms behind these associations, Kimberly suggested that the trillions of microbes in our gut and the molecules they produce likely play a crucial role.
"We are keen to understand how diet influences metabolites in the bloodstream," he noted. "The food we consume is metabolized by gut bacteria. It's intriguing that some metabolites linked to stroke and cognitive impairment are tied to specific foods and synthesized by the gut microbiome.
Hence, ultra-processed foods might also affect our gut microbiome, thereby impacting long-term brain health."
Regarding stroke risk, ultra-processed foods might exert both direct and indirect effects.
"Other studies have linked ultra-processed foods to high blood pressure, diabetes, and cardiovascular disease," Kimberly explained. "These conditions also elevate stroke risk. Thus, ultra-processed foods likely influence stroke risk both directly, by affecting cerebrovascular health, and indirectly, by contributing to conditions like high blood pressure, diabetes, and heart disease."
While the team's findings were observational, they align with a growing body of research suggesting that reducing ultra-processed food intake can enhance brain and overall health.
"Our study emphasizes the importance of mindful eating," Kimberly stated. "We should aim to increase our consumption of healthy foods, such as leafy greens, nuts, and fish-based proteins, while reducing our intake of prepackaged foods and sweet and salty snacks."
However, practicality is also essential.
"Ultra-processed foods are convenient, often have a longer shelf life, and are crafted to appeal to our taste buds. The encouraging news is that even modest reductions in ultra-processed food consumption were linked to better brain health," he said.
For more detailed information, the full study is available in Neurology, the American Academy of Neurology's medical journal.
