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Eating beans instead of bacon could help stave off cognitive decline, new research suggests.
Switching out one daily serving of processed meat for tofu, nuts, or beans could cut the risk of dementia by 20%, according to preliminary research presented at the 2024 Alzheimer's Association International Conference.
Researchers from the Harvard T.H. Chan School of Public Health looked at data from more than 130,000 American nurses over nearly four decades of follow-up.
They found that people who ate about a quarter of a serving of processed meat daily (about two servings a week) on average had a 14% higher risk of developing dementia compared to people who ate about three servings a month on average.
A serving of processed meat is about two slices of bacon, one hot dog, two small sausage links, or two ounces of deli meat (the amount in a typical sandwich).
The risk could be reduced by swapping out a daily serving of processed meat with legumes, the findings suggest.
The researchers also assessed overall cognitive function and found that, based on measures of function like processing and memory, each serving of processed meat participants ate in a typical day added about 1.61 to 1.69 years to their brain age.
In contrast, a serving of legumes instead of processed meat was linked to a brain age about 1.37 years younger, based on cognitive function.
The study is observational, meaning it doesn't directly show that processed meat increases the risk of cognitive decline.
But combined with previous evidence, the findings offer a compelling reason to consider cutting back in favor of nutrient-dense alternatives.
The potential negative effects of processed meat on the brain may be because of preservatives such as nitrites and sodium, according to Yuhan Li, lead of the study who conducted the research as a graduate student at Harvard T.H. Chan.
"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," Li said in a press release.
The latest research isn't the only evidence suggesting processed meat harms our health.
A July study found that cutting back on processed meat could reduce the risk of multiple diseases, including diabetes, heart disease, and cancer.
Previous evidence also suggests eating more processed meat is linked to a higher risk of breast cancer and colon cancer.
Nitrites used as preservatives in foods like processed meats have been classified as carcinogenic (cancer-causing) by the World Health Organization.
Processed red meats like sausage are also high in saturated fats and cholesterol, too much of which is linked to a higher risk of heart disease.
Legumes are a healthier alternative to processed meat not only because they're lower in preservatives, but also because they're packed with nutrients linked to major benefits for a long, healthy life.
Nuts are rich in healthy fats as well as fiber, a crucial nutrient for healthy digestion and a healthy gut.
Beans are also full of fiber and have been called a longevity superfood because they're a cheap, nutritious staple in the world's Blue Zones, where people are more likely to live to 100 or older.
A growing body of evidence suggests eating enough fiber to support your gut and the friendly microbes that live there play a crucial role in protecting brain health as you age.
