People who regularly consume processed red meat like bacon and sausages may face a higher risk of cognitive decline and dementia, according to new research that followed over 130,000 individuals for up to four decades.
The study, published in the January 15, 2025, issue of Neurology, found that eating just a quarter serving or more of processed red meat daily was associated with a 13% higher risk of developing dementia compared to those eating minimal amounts.
“Red meat is high in saturated fat and has been shown in previous studies to increase the risk of type 2 diabetes and heart disease, which are both linked to reduced brain health,” said study author Dr. Dong Wang of Brigham and Women’s Hospital in Boston.
The research team followed 133,771 people with an average age of 49 who were dementia-free at the start of the study. Participants regularly recorded their dietary habits, with researchers tracking their cognitive health for up to 43 years. During this period, 11,173 people developed dementia.
The findings showed that consuming processed meats like bacon, hot dogs, sausages, salami, and bologna carried particular risks. A serving size of red meat in the study was defined as three ounces – approximately the size of a deck of cards.
The study also examined how replacing red meat with other protein sources might affect brain health. Substituting one daily serving of processed red meat with nuts and legumes was associated with a 19% lower risk of dementia. Even more striking, replacing it with fish showed a 28% reduction in dementia risk, while switching to chicken was linked to a 16% lower risk.
Beyond dementia risk, the research examined cognitive decline in different groups. Among 43,966 older participants with an average age of 78, those eating a quarter serving or more of processed red meat daily showed a 14% higher risk of self-reported cognitive decline.
In a separate analysis of 17,458 female participants averaging 74 years old, researchers found that each additional daily serving of processed red meat was associated with approximately 1.6 years of accelerated brain aging in terms of global cognition and verbal memory.
“Our study found processed red meat may increase the risk of cognitive decline and dementia, but the good news is that it also found that replacing it with healthier alternatives, like nuts, fish and poultry, may reduce a person’s risk,” said Wang, adding that “reducing how much red meat a person eats and replacing it with other protein sources and plant-based options could be included in dietary guidelines to promote cognitive health.”
The researchers acknowledge some limitations of their work, including that the study primarily focused on white healthcare professionals, meaning the results might not apply equally to other demographic groups. They emphasize that more research is needed to assess their findings across more diverse populations.