Diet and dementia: How processed red meat impacts cognition and alternatives cut risks

Researchers are warning that eating processed red meat causes an increased risk of dementia and cognitive decline compared with people who eat very little meat.

The study in the journal Neurology adds that replacing red meat with nuts, fish or poultry may reduce the risk. Processed red meat includes bacon, hot dogs, sausages, salami and bologna.

According to the findings, US participants eating high levels of red meat had a 13% increased risk of brain aging in cognition and lower verbal memory than those in the low group. Faster brain aging includes global cognition and verbal memory. 

After 43 years, 11,173 of the 133,771 people who began the study with an average age of 49 and no dementia developed the disease. To measure cognitive decline, researchers looked at another group of 43,966 people with an average age of 78.

Red meat risks and alternatives 

The study suggests that replacing one serving per day of processed red meat with nuts and legumes can reduce the risk of dementia by 19% and lead to 1.37 fewer years of cognitive aging. Replacing the meat with fish may also reduce the risk of dementia by 28%, and replacing it with chicken was associated with a 16% lower risk.

Heavily processed meat diets have been associated with proinflammatory diets.

“Red meat is high in saturated fat and has been shown in previous studies to increase the risk of type 2 diabetes and heart disease, which are both linked to reduced brain health,” comments study author Dong Wang, MD, ScD, of Brigham and Women’s Hospital in Boston, US. 

Other recent research linked red or processed meat to increased colorectal cancer risk. A separate study underlined US consumers are among the world’s largest red meat eaters, with only 12% avoiding this diet.

Wang adds: “Our study found processed red meat may increase the risk of cognitive decline and dementia, but the good news is that it also found that replacing it with healthier alternatives, like nuts, fish and poultry, may reduce a person’s risk.”

Recently, scientists suggested replacing meat with plant protein lowers heart disease risk next to an Oxford study touting lowering mortality and disease risks, environmental resource use and pollution.

The study suggests that replacing one serving per day of processed red meat with nuts and legumes can reduce the risk of dementia by 19% and lead to 1.37 fewer years of cognitive aging.The latest US dietary guidelines committee also recommends including more nutrient-dense plant-based meals in the country’s dietary recommendations.

Study details 

The new study reveals that those in the high-consumption group ate 0.25 or more servings of processed red meat, while those in the low group ate an average of fewer than 0.10.

Participants kept a food diary that tracked their diets, including what they ate and how often, for two to four years. Researchers noted the amount of red meat participants consumed daily. They see unprocessed red meat such as beef, pork, lamb and hamburgers.

The team found no difference in dementia risk between groups consuming less than one-half serving of unprocessed red meat daily, on average, and people who ate one or more servings daily. 

The cognitive decline survey found that people who ate an average of 0.25 servings or more per day of processed red meat had a 14% higher risk of subjective cognitive impairment than those who ate an average of fewer than 0.10 servings.

Participants who ate one or more servings of unprocessed red meat daily had a 16% increased risk of subjective cognitive decline compared to those who ate less than half a serving. Subjective cognitive decline occurs when memory and thinking problems arise before appearing on standard tests.

High consumption of processed red meat was tied to faster brain aging, with each additional daily serving increasing brain aging by 1.61 years, while verbal memory increased by 1.69 years with each additional serving per day.

“Reducing how much red meat a person eats and replacing it with other protein sources and plant-based options could be included in dietary guidelines to promote cognitive health,” adds Wang. “More research is needed to assess our findings in more diverse groups.”