Consuming processed red meat may increase the risk of developing dementia and accelerate cognitive decline, according to new study findings. 

Replacing processed red meat with nuts and legumes may lower dementia risk and slow cognitive aging, according to findings of over 130,000 participants followed for up to 43 years. 

Researchers from the Harvard T.H. Chan School of Public Health and Brigham and Women's Hospital analyzed data from the Nurses' Health Study and Health Professionals Follow-Up Study. They assessed participants' diets every 2 to 4 years using food frequency questionnaires and identified 11,173 dementia cases during the follow-up period, according to findings presented at the Alzheimer's Association International Conference (AAIC) 2024 in Philadelphia.

Participants who consumed 0.25 servings or more of processed red meat daily had a 14% higher risk of dementia compared to those who ate less than 0.10 servings per day. Each additional daily serving of processed red meat was associated with 1.61 years of accelerated cognitive aging in global cognition and 1.69 years in verbal memory.

In a subset of 17,458 participants from the Nurses' Health Study, higher processed red meat intake was linked to a 14% increased likelihood of subjective cognitive decline for those consuming 0.25 servings or more daily compared to those who ate less than 0.10 servings. Unprocessed red meat intake of 1 serving or more per day, compared to less than 0.50 servings, was associated with a 16% higher likelihood of subjective cognitive decline.

Substitution analyses showed that replacing one serving of processed red meat per day with one serving of nuts and legumes was associated with a 23% lower risk of dementia, 1.37 fewer years of cognitive aging, and 20% lower odds of subjective cognitive decline.

Notably, the study found no significant association between unprocessed red meat intake and dementia risk.