New research following thousands of older Americans for seven years has identified two specific categories of ultra-processed foods that are strongly linked to memory loss and cognitive decline. The long-term study found that processed meats and sugar-sweetened beverages showed a distinct and measurable negative impact on brain health, suggesting that not all convenience foods carry the same level of risk for cognitive impairment as people age.
The findings, published in The American Journal of Clinical Nutrition, provide a more nuanced understanding of how diet affects the brain. While the broader category of ultra-processed foods—those containing numerous additives, preservatives, and artificial ingredients—is known to be detrimental to overall health, this study isolates the significant harm posed by daily consumption of items like sodas and processed deli meats. Researchers from Virginia Tech tracked U.S. residents aged 55 and older and discovered a 17% increase in cognitive issues among those who ate at least one serving of ultra-processed meat per day. Furthermore, each daily serving of a sugary drink was associated with a 6% increase in cognitive impairment, signaling a critical need for dietary awareness in preserving brain function.
A Seven-Year Study of Aging Brains
The investigation was conducted by Ben Katz, an associate professor of human development and family science, and Brenda Davy, a professor of human nutrition, foods, and exercise. They drew upon a robust and nationally representative dataset from the Health and Retirement Study, a longitudinal project that tracks the health of Americans over age 50. This allowed the researchers to analyze a large cohort of individuals over a significant period, adding weight and credibility to their conclusions. The study’s observation window began in 2013 and concluded in 2020, providing a clear picture of how dietary habits influenced cognitive trajectories over time.
Participants were evaluated every two years, allowing the research team to map the progression of cognitive changes relative to their reported food consumption. This repeated-measures design is crucial for establishing stronger associations than a one-time survey. By focusing on adults aged 55 and older, the study targets a demographic at a critical life stage where the initial signs of cognitive decline, including pre-dementia conditions, often begin to manifest. The comprehensive nature of the Health and Retirement Study dataset provided a solid foundation for analyzing these subtle yet significant changes in brain health as they developed over the seven-year period.
Measuring Cognitive Impairment
To assess brain function, the researchers employed a series of standardized tests that are commonly used in clinical and research settings to detect cognitive deficits. These evaluations were designed to probe different aspects of cognition, providing a holistic view of each participant’s mental acuity. The tests for memory included both immediate and delayed recall tasks, where individuals were asked to remember a list of words right after hearing it and then again after a short interval. This method helps differentiate between short-term and longer-term memory storage and retrieval, which can be affected differently by neurological changes.
Beyond memory, the cognitive assessment included tests of executive function and processing speed. Participants were asked to perform tasks such as counting numbers backward or subtracting a number repeatedly from a starting figure. These exercises require concentration, working memory, and mental flexibility. The scores from these various tests were used to measure global cognition. This allowed the researchers to identify a spectrum of brain health, ranging from mild cognitive impairment—an early stage of decline that can be a precursor to dementia—to more serious and pronounced cognitive deficits. According to Katz, these well-established evaluation methods are vital for identifying the risk factors that contribute to conditions like Alzheimer’s disease.
Specific Foods Tied to Accelerated Decline
A central and surprising finding of the study was the outsized role that processed meats and sugary drinks played in cognitive decline compared to other ultra-processed foods. While items like packaged snacks, frozen meals, and mass-produced breads are also heavily processed, they did not show the same strong, specific association with the negative outcomes measured in this study. This differentiation is a major contribution to the field, suggesting that certain food categories may have unique mechanisms of harm on the brain.
The Impact of Processed Meats
For individuals consuming at least one serving of ultra-processed meat daily, the study documented a 17% increase in the incidence of cognitive issues. This category includes products like cured bacon, sausages, hot dogs, and some deli meats that undergo significant modification with preservatives and additives. The findings point to a powerful dose-dependent relationship, where consistent consumption significantly elevates the risk of measurable cognitive harm over time.
The Role of Sugary Beverages
Sugar-sweetened beverages, primarily sodas, also emerged as a key factor. The research showed that for each daily serving of soda a participant consumed, their risk of developing cognitive impairment rose by 6%. This finding aligns with a growing body of evidence linking high sugar intake to negative neurological outcomes. The study underscores that even a single daily habit involving these drinks can contribute to a gradual but steady decline in brain health among older adults.
Expert Insights on Dietary Choices
Both lead researchers expressed that the specificity of the findings was unexpected. Katz noted that while many ultra-processed foods are known to be bad for cardiovascular health, the data indicated that the impact on cognition was “driven really meaningfully” by just a few categories that are staples in many American diets. He stressed the importance of these results for physicians, who can provide patients with more targeted and impactful dietary advice. The message is clear: the choices people make in the grocery aisle matter directly to their long-term brain health.
Brenda Davy highlighted the practical challenges that lead people to consume these foods. Ultra-processed options are often attractive because they are convenient and require little to no preparation time or cooking skill. This is a significant barrier for busy individuals and families. Davy emphasized that the solution is not just about telling people what to avoid but also about empowering them with the skills to make healthier choices. Making simple swaps, she explained, can have a major impact. For instance, consumers can read labels to find deli meats that are not ultra-processed or can commit to cooking more meals at home.
Future Research and Public Health Implications
The Virginia Tech team is continuing to explore the relationship between ultra-processed foods and cognition. A subsequent study focusing on the effects of these foods on young adults is currently under review, which could reveal how early in life these dietary patterns begin to affect the brain. Looking ahead, the researchers hope to secure grant funding to develop programs that teach cooking skills to individuals. The goal would be to evaluate whether improving culinary abilities leads to better dietary patterns and, in turn, measurable improvements in brain function.
Katz and Davy believe that addressing the skills gap is a crucial next step. Providing dietary guidelines is one thing, but giving people the practical ability to prepare healthy meals is another. By focusing on education and skill-building, they hope to create interventions that lead to lasting, positive changes in public health. The study serves as a critical wake-up call, reinforcing the idea that proactive, mindful dietary changes—particularly limiting processed meats and sugary drinks—are a vital strategy for anyone hoping to maintain a sharp and healthy brain throughout their later years.