A recent study has revealed a potential link between the consumption of processed red meat and an increased risk of dementia. The preliminary research, presented at the Alzheimer’s Association International Conference (AAIC) 2024, suggests that individuals who consume higher amounts of processed red meats, such as bacon, hot dogs, and sausages, may face a significantly elevated risk of developing dementia.
Key Findings:
According to the study, participants who consumed 0.25 or more servings of processed meat per day (approximately two servings per week) exhibited a 15% higher risk of dementia compared to those who consumed less than 0.10 serving per day (around three servings per month). Yuhan Li, MHS, research assistant at the Channing Division of Network Medicine, Brigham and Women’s Hospital, Boston, stated, “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.”
The study also indicated that substituting processed red meat with nuts and legumes could potentially mitigate this increased risk. This finding highlights a possible dietary intervention to promote cognitive health.
Study Methodology:
To explore the relationship between diet and dementia, researchers analyzed data from the Nurses’ Health Study and the Health Professionals Follow-Up Study. These long-term studies tracked the dietary habits of female registered nurses and male health professionals, respectively. Participants reported their processed red meat intake through validated food frequency questionnaires administered every 2-4 years.
The study assessed three cognitive outcomes: dementia, subjective cognitive decline, and objective cognitive function. Dementia was identified through self-reported physician diagnoses and dementia-related deaths. Subjective cognitive decline was evaluated based on participant reports of cognitive difficulties, while objective cognitive function was measured using the Telephone Interview for Cognitive Status.
Longitudinal Data and Results:
Over a follow-up period of 38 years (1980-2018), the study identified 6,856 cases of dementia among the participants. Those with a processed red meat intake of 0.25 servings per day or more had a 15% higher risk of dementia compared to those with lower intake (hazard ratio [HR], 1.15; 95% CI, 1.08-1.23; P < .001). Additionally, higher intake of processed red meat was linked to accelerated cognitive aging in global cognition and verbal memory.
The study also found that participants with higher processed red meat consumption had a 14% higher likelihood of subjective cognitive decline (odds ratio [OR], 1.14; 95% CI, 1.04-1.24; P = .004). For unprocessed red meat, consuming one or more servings per day was associated with a 16% higher likelihood of subjective cognitive decline (OR, 1.16; 95% CI, 1.04-1.30; P = .02).
Substitution Analysis:
Researchers modeled the effects of replacing one serving per day of processed red meat with nuts and legumes. This dietary substitution was associated with a 23% lower risk of dementia (HR, 0.77; 95% CI, 0.69-0.86), 1.37 fewer years of cognitive aging, and a 20% lower likelihood of subjective cognitive decline (OR, 0.80; 95% CI, 0.69-0.92).
Expert Opinions and Future Research:
The study has garnered attention for its large sample size, extensive follow-up period, and comprehensive assessment of dietary habits and cognitive outcomes. However, experts caution that the research is observational and cannot definitively establish causality. Kevin McConway, PhD, emeritus professor of applied statistics at the Open University in the UK, emphasized the need for more detailed, peer-reviewed reports to fully evaluate the study’s findings.
Sebastian Walsh, an NIHR doctoral fellow at the University of Cambridge, noted that while the study provides valuable insights, the analysis must account for other factors such as diet, age, ethnicity, and location. Claire Sexton, DPhil, senior director of scientific programs and outreach at the Alzheimer’s Association, highlighted the study’s unique aspect of showing the cognitive benefits of replacing processed red meat with nuts and legumes.
Conclusion:
Although the study suggests a link between processed red meat consumption and increased dementia risk, further research is necessary to confirm these findings and understand the underlying mechanisms. The researchers plan to investigate other modifiable factors affecting cognitive health. In the meantime, adopting a balanced diet that includes healthier alternatives like nuts and legumes may be a prudent approach to supporting brain health.