A new study shared at the 2024 Alzheimer’s Association International Conference has found that eating processed red meats like bacon and bologna daily can raise dementia risk by 14%. However, swapping these meats for nuts and legumes may decrease this risk by 20% and slow cognitive decline by more than a year. While a heart-healthy diet offers benefits, no individual food has been proven to prevent or cure Alzheimer’s, emphasizing the challenge of tackling dementia solely through dietary changes.
New Insights: Processed Red Meat and Cognitive Health
A groundbreaking study recently presented at the Alzheimer’s Association International Conference (AAIC) 2024 in Philadelphia and online has highlighted a significant connection between processed red meat consumption and an increased risk of dementia. According to the research, individuals who consume at least 1/4 serving of processed red meat daily — such as bacon, bologna, or other similar products—are more likely to develop dementia compared to those who eat less than 1/10 of a serving daily. Specifically, consuming just two servings of processed red meat per week can elevate the risk of dementia by 14%.
This study also reveals that making a simple dietary swap could have a profound impact on cognitive health. By replacing one daily serving of processed red meat with a serving of nuts or legumes, the risk of dementia could be reduced by as much as 20%. Additionally, this substitution could result in a reduction in cognitive aging by over a year, highlighting the potential benefits of a plant-based diet for brain health.
However, the researchers caution that while adopting a heart-healthy diet overall is beneficial, there is no conclusive evidence that any single food or ingredient can prevent or treat Alzheimer’s disease or other forms of dementia. The complexity of Alzheimer’s disease means that a multifaceted approach is necessary, and relying on dietary changes alone may not be sufficient to combat cognitive decline.
The Protective Power of Nuts and Legumes
The study in question monitored more than 130,000 participants from two large, long-term studies—the Nurses’ Health Study and the Health Professionals Follow-Up Study — over a span of up to 43 years. This extensive research aimed to examine the relationship between red meat consumption and the risk of developing dementia. During the study, 11,173 cases of dementia were identified.
Participants’ diets were meticulously assessed every 2 to 4 years using food-frequency questionnaires. These questionnaires asked about the frequency of consumption of processed red meats, such as bacon (two slices), hot dogs (one), sausages or kielbasa (2 ounces or two small links), salami, bologna, or other processed meat sandwiches. They also inquired about the consumption of nuts and legumes, including peanut butter (1 tablespoon), peanuts, walnuts or other nuts (1 ounce), soy milk (8-ounce glass), string beans, beans or lentils, peas or lima beans (1/2 cup), or tofu or soy protein.
The findings, presented for the first time at AAIC 2024, indicated a clear link between processed red meat consumption and an increased risk of dementia. Specifically, participants who consumed 1/4 serving or more of processed red meat daily had a 14% higher risk of developing dementia compared to those who ate less than 1/10 serving daily.
In addition to tracking dietary habits, the researchers evaluated cognitive function in 17,458 participants using the Telephone Interview for Cognitive Status. They found that each additional daily serving of processed red meat corresponded to an extra 1.61 years of cognitive aging for global cognition—an umbrella term that includes various aspects of cognitive function, such as language, executive function, and processing speed. Similarly, each extra serving was linked to an additional 1.69 years of cognitive aging in verbal memory, which is crucial for recalling and understanding words and sentences.
On the other hand, replacing one daily serving of processed red meat with a serving of nuts and legumes was associated with a 20% lower risk of developing dementia and 1.37 fewer years of cognitive aging in global cognition. These results suggest that plant-based proteins like nuts and legumes may offer significant protective benefits for cognitive health.
Processed Red Meat: A Significant Risk Factor
While previous studies have shown mixed results regarding the relationship between meat consumption and cognitive decline, this new research provides compelling evidence that processed red meat could be a significant risk factor for dementia. The researchers also investigated the impact of unprocessed red meat, such as hamburger, steak, or pork chops, and found no significant association between its consumption and dementia risk.
Heather Snyder, PhD, senior vice president of medical and scientific relations at the Alzheimer’s Association, emphasized the importance of these findings in an interview with Medical News Today. “It’s known that eating more ultra-processed foods is bad for cognitive health, and this study adds to a growing body of evidence on this subject,” said Snyder, who was not involved in the research.
She further explained that “processed red meat has already been shown to raise the risk of cancer, heart disease, and diabetes. It may impact brain health because it contains high levels of harmful substances such as nitrites (preservatives) and sodium.” However, Snyder also noted the limitations of the study, stating that “there is not a single food or ingredient that, through rigorous scientific research, has been shown to cause, increase risk, prevent, treat, or cure Alzheimer’s or other dementia.”
Megan Hilbert, RDN, a registered dietitian specializing in gut health nutrition and affiliated with Top Nutrition Coaching, who contributed to the research, also highlighted the detrimental effects of processed red meat on overall health. “For years now, we’ve known that eating enough processed red meat in the diet can have negative health implications like increased risk of certain cancers, increased risk of heart disease and stroke, and associations with obesity,” she said.
However, Hilbert also expressed optimism about the potential benefits of dietary changes. “The good news is that replacing processed red meat with nuts, beans, legumes, tofu, or other minimally processed soy [may potentially help] reverse that risk and has neuroprotective effects [against] symptoms of cognitive decline,” she added.
The Benefits of Plant-Based Proteins for Cardiovascular and Cognitive Health
The study’s findings underscore the importance of plant-based proteins not only for cardiovascular health but also for cognitive function. David Merrill, MD, PhD, a board-certified geriatric psychiatrist at Providence Saint John’s Health Center in Santa Monica, CA, and Singleton Endowed Chair in Integrative Brain Health, who was not involved in the research, spoke to Medical News Today about the significance of these results.
“[The study] provides strong evidence that healthy food choices over time indeed slow the rate of brain aging, reduce the risk of developing dementias like Alzheimer’s disease, and ultimately increase the odds of achieving successful aging—free of debilitating cognitive impairment,” Merrill said.
He also emphasized the importance of making healthier dietary choices. “It adds to the evidence behind limiting or ideally eliminating intake of processed red meats,” Merrill explained, “and making healthier dietary choices like eating nuts and beans regularly in place of processed red meat results in better outcomes with aging.”
Hilbert further elaborated on the possible reasons behind the association between processed red meat and dementia risk. “We aren’t 100% clear on why this association exists, but there are some theories as to why we see this increased risk,” she said.
One theory, according to Hilbert, is that “processed meats can impact the health of our cardiovascular system, which, of course, supplies oxygen and nutrients to our brain. When this connection is frayed, our brain may not perform optimally.” She also noted that “processed meats can cause excess inflammation, which can contribute to poor brain health by damaging brain cells.”
On the other hand, the nutrients found in nuts, seeds, beans, legumes, and soy may have the opposite effect. “Omega-3s, antioxidants, and phytonutrients in these foods can keep our cardiovascular system and brain cells healthy,” Hilbert explained.
Dietary Changes for Better Cognitive Health
In conclusion, the findings presented at AAIC 2024 reinforce the public health message of reducing processed meat consumption and increasing the intake of plant-based proteins like nuts and legumes. As Hilbert pointed out, “These findings further confirm the importance of reducing intake of processed meats in particular and adding more of these healthy plant-based proteins into patients’ diets.”
While it’s not necessary to completely eliminate meat from one’s diet, the evidence suggests that moderation is key. “We don’t have to completely cut out meat to be healthy,” Hilbert emphasized, “but more and more research shows us that less is more, especially with processed meats.”
As the research continues to evolve, it is clear that making informed dietary choices can play a crucial role in maintaining cognitive health and reducing the risk of dementia. While no single food or ingredient can prevent or cure Alzheimer’s disease, adopting a balanced diet rich in plant-based proteins may help protect against cognitive decline and promote overall brain health.