March 19, 2025
Red meat is a well-known risk factor for heart disease, and many studies suggest it may raise the risk of Alzheimer’s disease and other forms of dementia as well. But how much red meat does it take to raise dementia risk, and are certain types of red meat worse than others?
A new study found that processed red meat, like bacon, sausage, bologna or other deli meats, was especially bad for brain health. Eating about two servings a week of processed red meat raised the risk of dementia by about 14 percent compared to people who ate less than three servings a month.
A serving of red meat is roughly 3 ounces of cooked meat, or about the size of a deck of cards or the palm of your hand. That would be the equivalent of about three to four slices of bacon or salami.
Each additional daily serving of processed red meat was tied to an extra 1.6 years of brain aging. Declines were observed across a broad swath of memory and thinking skills, including verbal memory, or the ability to recall and understand words and sentences. Executive function, which helps people to plan, focus, remember instructions and juggle multiple tasks at the same time, was also negatively impacted. Executive function is one of the key skills lost as Alzheimer’s disease progresses.
“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. “Our study found processed red meat may increase the risk of cognitive decline and dementia.”
“The good news,” Dr. Wang added, “is that replacing red meat with healthier alternatives, like nuts, fish and poultry, may reduce a person’s dementia risk.” The study found that swapping a serving of processed red meat for a serving of fish, chicken, nuts, beans or tofu every day may lower the risk of dementia by around 20 percent. The findings were published in Neurology, the medical journal of the American Academy of Neurology.
For the study, researchers reviewed health data from more than 130,000 health professionals who were free of dementia at the start of the study period. Their average age was 49.
Every two to four years, study participants completed a detailed food diary, listing all the foods they typically ate and how often. The survey looked at more than 150 foods, including processed red meats such as bacon, hot dogs, sausages, salami, bologna and other deli meat products, as well as unprocessed red meat like beef, pork, lamb and hamburger. A subset of the older participants also completed questionnaires about whether they felt their memory and thinking skills remained intact.
Participants were followed for up to 43 years. By the end of the study period, 11,173 people had developed Alzheimer’s disease or other forms of dementia.
The researchers considered various risk factors for cognitive decline such as age, sex and other conditions and found that people who tended to eat more processed red meat had a higher risk of developing dementia than those who ate little of it. People who ate more processed red meat also had a higher risk of subjective cognitive decline.
Scientists aren’t sure why processed red meats are particularly bad for the brain. One possibility is that processed red meats are high in saturated fat and sodium, which may raise blood pressure and damage the brain over the long term. Nitrites and other chemicals in processed meat may also damage brain cells.
Unprocessed red meat appeared to be less damaging for brain health than processed red meats. The researchers found that people who ate more unprocessed red meat had a slightly higher risk of dementia than those who ate minimal amounts, though the results were not statistically significant.
Substituting processed red meat, on the other hand, lowered dementia risk. Replacing one daily serving of processed red meat with nuts or legumes was associated with a 19 percent lower risk of dementia, for example, while making the same substitution with fish or chicken was associated with a 28 percent or 16 percent respective lower risk.
“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,” Dr. Wang said. “We hope our results encourage greater consideration of the connection between diet and brain health.”
By ALZinfo.org, The Alzheimer’s Information Site. Reviewed by Eric Schmidt, Ph.D. Fisher Center for Alzheimer’s Research Foundation at The Rockefeller University.
Source: Yuhan Li, Yanping Li, Xiao Gu, et al: “Long-Term Intake of Red Meat in Relation to Risk of Dementia and Cognitive Function in US Adults.” Neurology, January 15, 2025
