Eating a lot of red meat increases the risk of dementia and cognitive decline

For people who like to eat regularly red meat – particularly processed foods like bacon, sausages, hot dogs and bologna – the risks of mental decline are significantly higher than those who eat smaller amounts of red meat, according to a study published this week in Neurologythe journal of the American Academy of Neurology.

Based on results from nearly 130,000 adults, the findings contribute to a growing body of research suggesting that red meat, rich in saturated fatscan be bad for the brain.

“Our results provide further evidence that higher consumption of red meat, particularly consumption of processed red meat, is associated with a higher risk of cognitive decline and dementia,” explains Yuhan Li, PhDassistant professor of anesthesia at Brigham and Women’s, a teaching hospital affiliated with Harvard Medical School in Boston.

“Additionally, our findings highlight the benefits of replacing processed red meat with healthier alternatives, such as nuts and legumes, contributing to the development of practical dietary advice to improve eating habits to support health cognitive. »

Higher consumption of red meat linked to increased risk of dementia

To measure the risk of dementia By eating red meat, Dr Li and his team followed around 134,000 people for 43 years. The participants were on average 49 years old and did not suffer from dementia at the start of the research. They filled out a food diary every two to four years, listing what they ate and how often. By the end of the study, 11,173 (8.3%) had developed dementia.

Processed red meats were defined as products such as bacon, hot dogs, sausages, salami and bologna, while unprocessed red meats were defined as beef, pork, lamb and hamburger. . One serving was considered the equivalent of 3 ounces, or about the size of a deck of cards.

For the analysis of processed meat, participants were separated into three groups. On average, the low-intake group ate less than a tenth of a serving per day (or about three servings per month), the average group ate between a tenth and less than a quarter of a serving per day, and the high-intake group ate a quarter serving or more per day (or about two servings at least per week).

The results showed that those who consumed the most processed meat were 13 percent more likely to develop dementia than those in the low consumption group.

To assess dementia risk from unprocessed red meat, researchers compared individuals who on average consumed less than half a serving per day with those who ate one or more servings per day. They found no difference in dementia risk.

Assessment of cognitive decline

To assess cognitive decline, scientists analyzed subjective measures based on surveys in which participants rated their own memory and thinking skills twice during the study. They also weighted objective measures based on memory, thinking and problem-solving tests taken four times during the study.

In the subjective group, which included about 44,000 participants with an average age of 78, those who ate an average of at least a quarter serving of processed red meat per day had a 14% higher risk of cognitive decline than those who ate it. . less than a tenth of a portion.

The researchers also highlighted that those who ate one or more servings of unprocessed red meat per day had a 16% higher risk of subjective cognitive decline than those who ate less than half a serving per day.

From the objective group analysis, which included approximately 17,000 participants with an average age of 74, the study authors found that consumption of processed red meat was associated with faster brain aging, the brain being “older” by 1.61 years with each additional serving per serving. day.

Why is processed meat bad for the brain?

The high saturated fat content of red meats – whether processed or not – could be one of the main contributors to mental decline, according to Li.

High LDL cholesterol and diabetes are both known risk factors for dementia, according to the Alzheimer’s Drug Discovery Foundation.

For Yuko Hara, PhDdirector of aging and Alzheimer’s prevention at the Alzheimer’s Drug Discovery Foundation, the difference between processed and unprocessed red meats may be due to ingredients added to processed products.

“Processed meat contains preservatives that are not present in fresh meat, such as nitriteswhich can turn into harmful compounds that increase oxidative stress and inflammation,” says Dr. Hara. “Processed meat also contains high levels of sodium, which can lead to high blood pressurea well-established risk factor for dementia.

Heather Snyder, Ph.D.senior vice president of medical and scientific relations for the Alzheimer’s Association, confirms that it is ultra-treatments that can be particularly harmful to the brain.

“For example, a report from the Alzheimer’s Association International Conference (AAIC) 2022 found that people who consume large amounts of ultra-processed foods experience more rapid cognitive decline,” says Dr. Snyder. “More than 20 percent daily consumption of ultra-processed foods resulted in a 28 percent faster decline in overall cognitive scores, including memory and verbal fluency.”

Replace red meat with healthier alternatives

The study authors also looked at the data to see how people could reduce risk, and they found that replacing one serving per day of processed red meat with one serving per day of processed meat nut And beans was associated with a 19 percent lower risk of dementia and 1.37 fewer years of cognitive aging.

Making the same substitution of fish was linked to a 28 percent lower risk of dementia, and replacing it with chicken was associated with a 16 percent lower risk of dementia.

Rebecca Beaudoin, RDNa nutritional therapist at Nebraska Medicine in Omaha, particularly emphasizes the value of eating more plants in your diet.

“We know that increasing plant consumption is associated with better health,” says Beaudoin. “As we increase our consumption of fruits, vegetables, beans and whole grains, we increase both our fiber, which is anti-inflammatory, and our phytochemicals, natural substances that can help protect against cellular damage. »