A study recently presented at AAIC 2024 showed that higher consumption of processed red meat significantly increased the risk of dementia and cognitive decline among adults in the United States.
Heather M. Snyder, PhD
(Credit: Alzheimer’s Association)
A new prospective study presented at the 2024 Alzheimer’s Association International Conference, July 28 to August 1, in Philadelphia, Pennsylvania, using data from the Nurses' Health Study (NHS) showed that higher intake of red meat, particularly processed red meat, was associated with a higher risk of developing dementia and worse cognition among adults in the United States.1 These findings suggest that patients can decrease their risk of dementia by replacing one serving of processed red meat with one serving of nuts and legumes.2
In follow-up data comprising 38 years (1980-2018), investigators documented 6856 dementia cases. In the analysis, patients with a processed intake of red meat of at least 0.25 serving/day, as compared with less than 0.10 serving/day, revealed a 15% higher risk of dementia (HR = 1.15; 95% CI, 1.08-1.23; P Linearity <.001). Notably, results also showed a significant association between higher processed red meat intake and accelerated 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 Linearity = .03).
“Prevention of AD and all other dementia is a major focus, and the Alzheimer’s Association has long encouraged eating a healthier diet — including foods that are less processed — because they’ve been associated with lower the risk of cognitive decline,” Heather M. Snyder, PhD, vice president of medical and scientific relations at Alzheimer’s Association, said in a statement.2 “This large, long-term study provides a specific example of one way to eat healthier.”
In the study, investigators evaluated diet intake every 2 to 4 years using food-frequency questionnaires and assessed incident dementia cases by self-report and death records in 87,424 patients who were free from Parkinson disease or baseline dementia, stroke, or cancer from the NHS. In a subset of 17,458 patients from NHS, researchers assessed cognitive function using the Telephone Interview for Cognitive Status (1995-2008). Authors then gathered longitudinal data on subjective cognitive decline from 33,908 participants in the NHS and 10,058 participants from the Health Professionals Follow-Up Study.
Additional findings showed that patients who had a processed red meat intake of at least 0.25 serving/day revealed a 14% higher likelihood of subjective cognitive decline compared with patients who had an intake less than 0.10 serving/day (OR = 1.14; 95% CI, 1.04–1.24; P Linearity = .004). Furthermore, results demonstrated that unprocessed red meat intake of at least 1.00 serving/day compared with 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 Linearity = .02).
“Study results have been mixed on whether there is a relationship between cognitive decline and meat consumption in general, so we took a closer look at how eating different amounts of both processed and unprocessed meat affects cognitive risk and function,” lead author Yuhan Li, MHS, research assistant in the Channing Division of Network Medicine at Brigham and Women’s Hospital, said in a statement.2 “By studying people over a long period of time, we found that eating processed red meat could be a significant risk factor for dementia. Dietary guidelines could include recommendations limiting it to promote brain health.”
In substitution analyses, investigators noted that having a replacement of 1 serving/day of processed red meat with 1 serving/day of nuts and legumes was associated with a 23% lower risk of dementia (HR = 0.77; 95% CI, 0.69–0.86). This replacement was also associated with 1.37 fewer years of cognitive aging (95% CI, -2.49 to -0.25), and 20% lower odds of subjective cognitive decline (OR = 0.80; 95% CI, 0.69–0.92).
“Processed red meat has also been shown to raise the risk of cancer, heart disease and diabetes. It may affect the brain because it has high levels of harmful substances such as nitrites (preservatives) and sodium,” Li said in a statement.2
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