People who eat more red meat, especially processed red meat such as bacon, sausage and bologna, are more likely to have a higher risk of cognitive decline and dementia compared to those who eat very little red meat, according to a study published in January. 15, 2025, online edition of Neurology®the medical journal of the American Academy of Neurology.
“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, both of which are linked to reduced brain health,” said study author Dong Wang, MD, ScD. , from Brigham and Women’s Hospital in Boston. “Our study found that processed red meat can increase the risk of cognitive decline and dementia, but the good news is that it also found that replacing it with healthier alternatives, such as nuts, fish and poultry, can reduce a person’s risk.”
To examine the risk of dementia, the researchers included a group of 133,771 people with an average age of 49 years who did not have dementia at the start of the study. They were followed until they were 43 years old. Of this group, 11,173 people developed dementia.
Participants completed a food diary every two to four years, listing what they ate and how often.
The researchers defined processed red meat as bacon, hot dogs, sausages, salami, bologna, and other processed meat products. They defined unprocessed red meat as beef, pork, lamb, and hamburger. A serving of red meat weighs three ounces, about the size of a deck of cards.
The researchers calculated how much red meat the participants ate on average per day.
For processed red meat, they divided the participants into three groups. The low group consumed an average of less than 0.10 servings per day; the medium group ate between 0.10 and 0.24 servings per day; and the high group, 0.25 or more servings per day.
After adjusting for factors such as age, sex and other risk factors for cognitive decline, the researchers found that participants in the high group had a 13% higher risk of developing dementia compared to those in the low group.
For unprocessed red meat, researchers compared people who ate an average of less than half a serving per day with people who ate one or more servings per day and found no difference in dementia risk.
To measure subjective cognitive decline, the researchers looked at a different group of 43,966 participants with an average age of 78 years. Subjective cognitive impairment is when a person reports memory and thinking problems before any impairment is large enough to show up on standard tests.
The group with subjective cognitive impairment took surveys rating their own memory and thinking skills twice during the study.
After adjusting for factors such as age, sex, and other risk factors for cognitive decline, the researchers found that participants who ate an average of 0.25 servings or more per day of processed red meat had a 14% higher risk of decline. subjective cognitive compared to those who ate an average of less than 0.10 servings per day.
They also found that people who ate one or more servings of unprocessed red meat per day had a 16% higher risk of subjective cognitive decline compared to people who ate less than half a serving per day.
To measure objective cognitive function, the researchers looked at a different group of 17,458 female participants with an average age of 74 years. Objective cognitive function is how well your brain works to remember, think, and solve problems.
This group took memory and thinking tests four times during the study.
After adjusting for factors such as age, sex and other risk factors for cognitive decline, the researchers found that eating more processed red meat was associated with faster brain aging in global cognition at 1.61 years with each serving. additional per day and in verbal memory with 1.69 years. with each additional serving per day.
Finally, the researchers found that replacing one daily serving of processed red meat with one daily serving of nuts and legumes was associated with a 19% lower risk of dementia and 1.37 fewer years of cognitive aging. Making the same substitution for fish was associated with a 28% lower risk of dementia, and replacing it with chicken was associated with a 16% lower risk of dementia.
“Reducing the amount of 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,” Wang said. “More research is needed to evaluate our findings in groups.” more diverse”.
One limitation of the study was that it focused primarily on white health professionals, so the results may not be the same for populations of other races, ethnicities, and non-binary sexes and genders.
The study was supported by the National Institutes of Health.