Eating processed red meat may be a significant risk factor for dementia, according to a large study involving more than 100,000 people over four decades.
Processed red meat has previously been shown to increase the risk of cancer, heart disease and type 2 diabetes. Now, US researchers say they have discovered a possible link to dementia.
The study also found that replacing processed red meat with healthier foods such as nuts, beans or tofu could help reduce the risk of dementia. The findings were presented at the Alzheimer’s Association International Conference in the US.
The number of people with dementia worldwide is expected to nearly triple to 153 million by 2050, prompting researchers to increasingly focus on nutrition and the risk of cognitive decline.
In the latest study, experts studied the health of 130,000 nurses and other health care workers working in the U.S. They were followed for 43 years, providing data on their diets every 2 to 5 years.
Participants were asked how often they ate processed red meat, such as bacon, hot dogs, sausages, salami and other cold cuts.
They were also asked about their consumption of nuts and legumes, including peanut butter, peanuts, walnuts and other nuts, green beans, beans, peas, soy milk and tofu.
During the follow-up period, more than 11,000 cases of dementia were identified.
According to the researchers, eating two servings of processed red meat per week increased the risk of cognitive decline by 14% compared to people who eat about three servings per month.
The study also found that replacing one daily serving of processed red meat with a daily serving of nuts, beans or tofu could reduce the risk of dementia by 23%.
The study’s lead author, Dr. Yuhan Li, an assistant professor at Brigham and Women’s Hospital in Boston, said: “Research results have been mixed about whether there is a link between cognitive decline and meat consumption in general. So we took a closer look at how eating different amounts of processed and unprocessed meat affects cognitive risk and function.
“By studying people over a long period of time, we found that eating processed red meat may be a significant risk factor for dementia.”
Li, who conducted the research while at the Harvard TH Chan School of Public Health in Boston, added: “Dietary guidelines could include recommendations to limit the consumption of these foods to promote brain health.
“Processed red meat has also been shown to increase the risk of cancer, heart disease and diabetes. It can damage the brain because it contains high levels of harmful substances such as nitrites (preservatives) and sodium.”
Dr Heather Snyder of the Alzheimer’s Association said: “Prevention of Alzheimer’s disease and all other dementias is a major focus, and the Alzheimer’s Association has long encouraged healthier eating – including fewer processed foods – as these have been linked to a lower risk of cognitive decline. This large, long-term study provides a specific example of one way to eat healthier.”
Dr Richard Oakley from the Alzheimer’s Society in the UK said: “In this study, more people who ate processed red meat developed dementia and had poorer memory and thinking skills.”
However, he urged caution, saying the study only found a link between processed red meat and dementia — and provided no evidence of cause and effect.
“It’s important to remember that this doesn’t mean that eating processed red meat is directly related to developing dementia. It could be that people who avoid processed red meat are generally more health-conscious and avoid other unhealthy habits that increase the risk of dementia.”