Eating Meat May Protect People at Risk of Alzheimer’s Disease

A 15-year Swedish study finds meat may shield carriers of the APOE4 gene against Alzheimer’s—unless they’re eating processed meats.

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Eating more meat may help protect memory in older adults who carry a common Alzheimer’s risk gene, according to a new long-term study from Sweden.

Among people carrying the APOE4 gene, a gene that puts people at risk of developing Alzheimer’s disease, those who ate the most meat in their weekly diets showed slower declines in memory and thinking compared with those who ate the least meat.

“Those who ate more meat overall had significantly slower cognitive decline and a lower risk of dementia, but only if they had the APOE 3/4 or 4/4 gene variants,” first author Jakob Norgren, a researcher at Karolinska Institutet, said in a statement.

Published in JAMA Network Open, the study followed more than 2,000 adults older than age 60, and suggests that general dietary advice for brain health needs to be more tailored to a person’s genetic profile.

The APOE4 gene is the strongest genetic risk factor for Alzheimer’s disease, although carrying it does not mean that a person will develop the condition. People can inherit one or two copies—often written as 3/4 or 4/4.

About one in four Americans carries at least one copy of the APOE4 gene, while roughly two-thirds of people with Alzheimer’s disease carry the gene.

The Meat of the Matter

Researchers split participants into five groups based on how much meat they ate, adjusting for overall calories. Those in the highest group ate about 870 grams per week—roughly 1 1/2 servings a day—while those in the lowest group ate less than half that amount.

Among people with the APOE4 gene, those who ate the least meat had more than double the dementia risk of people without the gene. But among the highest meat eaters, that risk gap narrowed to the point where it was no longer statistically significant—for both dementia and overall cognitive decline.

The findings suggest that one-size-fits-all dietary advice does not work for everyone. For some APOE4 carriers, eating very low amounts of meat may not be optimal for brain health.

“Our findings suggest that conventional dietary advice may be unfavourable to a genetically defined subgroup of the population,” Norgren said.

Not all meat appeared equal, however. Diets higher in processed meats—such as bacon, sausages, and deli meats—were linked to a higher risk of dementia regardless of genetic background. The apparent benefit among APOE4 carriers was tied only to eating more unprocessed meat, such as fresh red meat and poultry.

Researchers also saw a lower overall death risk among APOE4 carriers whose diets were higher in unprocessed meats.

All participants were free of dementia at the start. The 15-year study drew on data from the Swedish National Study on Aging and Care–Kungsholmen (SNAC‑K). Participants completed detailed food‑frequency questionnaires, and researchers tracked changes in cognitive function over time along with new dementia diagnoses.

The APOE4 Connection

For people with the APOE4 gene, diet likely matters because this gene helps control how the body handles fats and certain nutrients, including vitamin B12.

Vitamin B12 is essential for nerve function and is found mainly in animal products, especially meat, fish, eggs, and dairy. Earlier studies have shown that APOE4 carriers with low B12 levels are more vulnerable to cognitive decline and poorer brain health.

In the new study, APOE4 carriers who ate more meat showed higher B12 levels in their blood than people who ate less. The study also suggested that carriers of APOE4 were better able to absorb vitamin B12 from meat compared with those with other variants of APOE.

More broadly, APOE helps move cholesterol and other fats through the bloodstream and into the brain, where they are used as fuel and as building blocks for brain cells. The APOE4 variant has been linked to less efficient handling of these fats and to a higher risk of Alzheimer’s‑related brain changes over time.

“APOE4 is the evolutionarily oldest variant of the APOE gene and may have arisen when our ancestors ate a more animal‑based diet,” Norgren said. That history, he and colleagues suggest, could help explain why carriers may respond better to diets that include more animal‑based foods.

For people who do not carry APOE4, research suggests that eating a balanced diet is more protective of brain health. “I would say the best diet is a plant‑based diet with occasional fish,” Dr. Murali Doraiswamy, a psychiatrist at Duke University who specializes in brain aging, told The Epoch Times in a previous interview.

Diets built around vegetables, whole grains, beans, and low‑fat dairy—such as the DASH and MIND diets—have been found to lower blood pressure and support healthier blood vessels, which in turn supports brain health.

The new study was observational. Clinical trials will be needed to determine whether diet is directly driving these effects.

Still, the results suggest that Alzheimer’s risk may be shaped by simple food choices.

“For people who know they carry APOE4, the findings offer hope,” Norgren said. “The risk may be modified through lifestyle.”