PHILADELPHIA – preliminary research shows.
Study participants who consumed 0.25 or more servings of processed meat per day, or roughly two servings per week, had a 15% higher risk for dementia, compared with those who consumed less than 0.10 serving per day, which is about three servings per month.
“Our study found a higher intake of red meat — particularly processed red meat — was associated with a higher risk of developing dementia, as well as worse cognition,” said study author Yuhan Li, MHS, research assistant, Channing Division of Network Medicine, Brigham and Women’s Hospital, Boston, Massachusetts.
However, the study also showed that replacing processed red meat with nuts and legumes could potentially lower this increased risk.
The findings were presented on at the 2024 Alzheimer’s Association International Conference (AAIC).
Inconsistent Research
Previous studies have shown an inconsistent association between red meat intake and cognitive health.
To assess the relationship between diet and dementia, the researchers used data from the Nurses’ Health Study, which began recruiting female registered nurses aged 30-55 years in 1976, and the Health Professionals Follow-Up Study, which began recruiting male health professionals aged 40-75 in 1986.
They assessed processed red meat intake by validated semi-quantitative food frequency questionnaires administered every 2-4 years. Participants were asked how often they consumed a serving of processed red meat.
Investigators also assessed intake of unprocessed red meat, including beef, pork, or lamb as a main dish, in a sandwich or hamburger, or in a mixed dish.
The investigators also looked at participants’ intake of nuts and legumes.
Dementia outcome was a composite endpoint of self-reported dementia and dementia-related death. “Specifically, participants reported a physician diagnosis of Alzheimer’s disease or other forms of dementia by questionnaire. Deaths were identified through state vital statistics records, the National Death Index, family reports, and the postal system,” said Ms. Li.
Three Cognitive Outcomes
Researchers examined three outcomes: dementia, subjective cognitive decline, and objective cognitive function. For dementia, they ascertained incident cases in 87,424 individuals in the UK’s National Health Service database without Parkinson’s disease or baseline dementia, stroke, or cancer.
They longitudinally collected information on subjective cognitive decline from 33,908 Nurses’ Health Study participants and 10,058 participants in the Health Professionals Follow-Up Study.
Cognitive function was assessed using the Telephone Interview for Cognitive Status (1995-2008) in a subset of 17,458 Nurses’ Health Study participants.
Over a follow-up of 38 years (1980-2018), there were 6856 dementia cases in the Nurses’ Health Study. Participants with processed red meat intake of 0.25 or more serving/day, compared with less than 0.10 serving/day, had 15% higher risk for dementia (hazard ratio [HR], 1.15; 95% CI, 1.08-1.23; P < .001).
In addition to an increased risk for dementia, intake of processed red meat was associated with accelerated cognitive aging in global cognition (1.61 years per 1–serving/day increment; 95% CI, 0.20, 3.03) and verbal memory (1.69 years per 1–serving/day increment; 95% CI, 0.13, 3.25; both P = .03).
Participants with processed red meat intake of 0.25 or more serving/day had a 14% higher likelihood of subjective cognitive decline, compared with those with intake less than 0.10 serving/day (odds ratio [OR], 1.14; 95% CI, 1.04-1.24; P = .004).
For unprocessed red meat, consuming 1.00 or more serving/day versus less than 0.50 serving/day was associated with a 16% higher likelihood of subjective cognitive decline (OR, 1.16; 95% CI, 1.04-1.30; P = .02).