"We found that eating processed red meat could be a significant risk factor for dementia."
The study also linked each additional daily serving of processed red meat to more than 1.6 years of cognitive aging for overall cognitive function and nearly 1.7 years for verbal memory.
"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 researcher Yuhan Li, an assistant professor at the Brigham and Women's Hospital in Boston, said in a statement.
"By studying people over a long period of time, we found that eating processed red meat could be a significant risk factor for dementia," she added.
Heather Snyder, the Alzheimer's Association vice president of medical and scientific relations, toldNBC News that "this is really consistent with a larger body of science that tells us that diets that are lower in fat, lower in sugar, higher in vegetables overall, are what's really better for our brain health."
Li recommends including recommendations to limit processed red meat consumption in official dietary guidelines.
"Processed red meat has also been shown to raise the risk of cancer, heart disease, and diabetes," she said. "It may affect the brain because it has high levels of harmful substances such as nitrites and sodium."
The good news is that the researchers found that replacing one daily serving of processed red meat with foods including beans, nuts, and tofu could result in a 20% lower risk of dementia.
Furthermore, some experts said that while the new study showed more people who consumed processed red meat developed dementia, the research does not show cause and effect.
"It's important to remember that this doesn't mean that eating processed red meat is directly related to developing dementia," Richard Oakley of the U.K. Alzheimer's Association toldThe Guardian. "It may be that people who avoid processed red meat are generally more health conscious and avoid other unhealthy habits that increase dementia risk."
In addition to the health risks of eating both processed and unprocessed meats, animal agriculture also exacerbates the climate emergency. A 2020 study by researchers at the University of Michigan and Tulane University commissioned by the Center for Biological Diversity, a conservation group, found that if Americans halved their consumption of animal products, it could prevent 1.6 billion tons of greenhouse gas emissions within a decade.