Processed red meat linked to higher risk of dementia

Summary: A study of more than 133,000 people found that daily consumption of processed red meat increases the risk of dementia by up to 13%, while replacing it with alternatives like nuts, legumes or fish can reduce the risk by 20%. Higher consumption of processed meat was associated with accelerated cognitive aging and increased subjective cognitive decline (SCD).

Researchers suggest that saturated fat, salt, and changes to the gut microbiome, including TMAO production, may link red meat to dementia risk. These findings highlight the importance of food choices for physical and cognitive health, highlighting the potential for reducing dementia risk through simple dietary changes.

Key facts:

• Risk of dementia: Daily consumption of processed red meat increases the risk of dementia by 13%, with cognitive aging accelerated by 1.6 years per serving.
• Protection alternatives: Replacing processed red meat with nuts, legumes or fish reduces the risk of dementia by 20%.
• Gut-brain link: The impact of red meat on the gut microbiome, including TMAO production, may contribute to cognitive dysfunction.

Source: General Mass

Consumption of red meat is an established risk factor for chronic diseases, including cardiovascular disease and type 2 diabetes.

A new study led by researchers at Mass General Brigham, the Harvard TH Chan School of Public Health, and the Broad Institute of MIT and Harvard found that consuming greater amounts of red meat, especially in its processed forms, also increased the risk of dementia.

Results, published online on January 15, 2025 in Neurologythe medical journal of the American Academy of Neurology, points out that replacing processed red meat with protein sources like nuts, legumes or fish can reduce the risk of dementia by about 20 percent.

“Dietary guidelines tend to focus on reducing the risks of chronic diseases like heart disease and diabetes, while cognitive health is less frequently discussed, although it is linked to these diseases,” said the corresponding author Daniel Wang, MD, ScD, of the Channing Division of the network. Medicine at Brigham and Women’s Hospital, a founding member of the Mass General Brigham Health System. Wang is also an associate member of the Broad Institute and an assistant professor in the Department of Nutrition at the Harvard Chan School.

“We hope our results will encourage greater consideration of the link between diet and brain health.” »

As the U.S. population ages, dementia presents an increasing challenge for patients and their families. Of the 133,771 people included in this study, with a mean age of 49 at baseline, 11,173 were diagnosed with dementia up to 43 years later.

The data was drawn from the Nurses’ Health Study (NHS) and the Health Professionals Follow-up Study (HPFS), which prospectively study the health and lifestyles of thousands of participants, who may influence the risk of chronic diseases such as dementia.

The studies include decades of detailed health information, including participants’ typical diets, which they update every 2 to 4 years.

A typical serving of red meat is 3 ounces, or about the size of a bar of soap. Those who consume on average a quarter or more of a serving of processed red meat daily (about two slices of bacon, a slice and a half of bologna, or a hot dog), compared to those who consume a minimal amount (less of one – tenth per serving each day), had a 13 percent higher risk of developing dementia, controlling for many clinical, demographic and lifestyle factors such as socioeconomic status and family history of dementia.

The researchers measured objective cognitive function using standard cognitive assessments. They found that this measure was also worse among those who ate more processed meat, with cognitive aging accelerated by about 1.6 years per average daily serving.

The researchers also looked at self-reported subjective cognitive decline (SCD), which may precede markers of cognitive decline on standard assessments. A higher risk of SCD was associated with eating processed or unprocessed meats (such as beef, pork, and hamburgers).

SCD risk increased by 14 percent for those eating a quarter or more servings of processed meat daily compared to the minimal intake group, and by 16 percent for those eating one or more servings daily of unprocessed meat compared to those who eat less than half. portion.

Researchers continue to explore factors linking red meat to dementia risk, particularly those involving the gut microbiome.

Trimethylamine N-oxide (TMAO), a product of the breakdown of meat by bacteria, may increase cognitive dysfunction due to its effects on the aggregation of amyloid and tau, proteins involved in Alzheimer’s disease, but research is limited.

The saturated fat and salt content of red meat can also harm brain cell health.

“Large-scale, long-term cohort studies are essential to study diseases such as dementia, which can develop over decades,” Wang said.

“We continue to piece together this story to understand the mechanisms behind dementia and cognitive decline. »

Funding: This study was supported by the National Institutes of Health (R01AG077489, RF1AG083764, R00DK119412, R01NR019992, and P30DK046200).

About this research news on diet and dementia

Author: Brandon Chase
Source: General Mass
Contact: Brandon Chase – Mass General
Picture: Image is credited to Neuroscience News

Original research: Closed access.
“Long-term consumption of red meat in relation to dementia risk and cognitive function among US adults” by Yanping Li et al. Neurology

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Abstract

Long-term red meat consumption in relation to dementia risk and cognitive function among US adults

Context and objectives

Previous studies have shown inconsistent associations between red meat consumption and cognitive health. Our objective was to examine the association between red meat consumption and multiple cognitive outcomes.

Methods

In this prospective cohort study, we included participants free of dementia at baseline from 2 national cohort studies in the United States: the Nurses’ Health Study (NHS) and the Health Professionals Follow-Up Study (HPFS). Diets were assessed using a validated semi-quantitative food frequency questionnaire.

We found incident cases of dementia in NHS (1980-2023) and HPFS (1986-2023) participants. Objective cognitive function was assessed using the Cognitive Status Telephone Interview (1995–2008) in a subset of NHS participants. Subjective cognitive decline (SCD) was self-reported by participants in the NHS (2012, 2014) and HPFS (2012, 2016).

Cox proportional hazards models, general linear regression models, and Poisson regression models were applied to evaluate the associations between red meat consumption and different cognitive outcomes.

Results

The dementia analysis included 133,771 participants (65.4% female) with a mean baseline age of 48.9 years, the objective cognitive function analysis included 17,458 participants with a mean age of 74 ,3 years and the SCD analysis included 43,966 participants (77.1% female) with a mean baseline age of 77.9 years.

Participants consuming processed red meat ≥0.25 servings per day, compared to p_linearity p_linearity = 0.004).

Higher consumption of processed red meat was associated with accelerated aging in overall cognition (1.61 years per increment of 1 serving per day (95% CI 0.20-3.03)) and verbal memory ( 1.69 years per increment of 1 serving per day (95% CI 0.13-3.25), both p_linearity = 0.03). Unprocessed red meat consumption of ≥1.00 servings per day, compared to p_linearity = 0.04).

Replacing one serving per day of nuts and legumes with processed red meat was associated with a 19% lower risk of dementia (HR 0.81, 95% CI 0.75-0.86), compared to 1 .37 fewer years of cognitive aging (95% CI -2.49 to -0.25). ), and a 21% lower risk of sickle cell disease (RR 0.79, 95% CI 0.68 to 0.92).

Discussion

Higher consumption of red meat, particularly processed red meat, was associated with a higher risk of developing dementia and poorer cognition. Reducing red meat consumption could be included in dietary guidelines to promote cognitive health. Further research is needed to assess the generalizability of these findings to populations of diverse ethnic backgrounds.