Older adults who carry the APOE 4 gene – a known risk factor for Alzheimer’s – may not see the usual decline in memory if they eat a fair amount of meat. This finding comes from a recent study by researchers at Karolinska Institutet, published in JAMA Network Open. The work hints that diet advice could one day be matched to a person’s DNA.
The APOE gene controls how the brain moves cholesterol and fats. About 30 % of Swedes have one of the higher‑risk versions (APOE 3/4 or APOE 4/4). Among people diagnosed with Alzheimer’s, nearly 70 % carry one of these variants.
Swedish health officials recently asked scientists to study how meat affects dementia risk. The new research followed more than 2,100 people aged 60 or older. None of them had dementia when the study began, and they were observed for up to 15 years.
Participants reported what they ate, and researchers measured their thinking abilities over time. They also took into account age, sex, education and lifestyle.
Meat Intake and Dementia Risk
People who ate little meat and also had the APOE 3/4 or APOE 4/4 genes faced more than double the chance of developing dementia compared with those without these genes.
Strangely, the extra risk disappeared in the group that ate the most meat. The highest‑eating participants consumed about 870 grams of meat each week (roughly three servings) while keeping their daily calories around 2,000.
"Those who ate more meat showed slower thinking decline and a lower dementia risk, but only if they carried the APOE 3/4 or 4/4 variants," said lead researcher Jakob Norgren.
Processed vs. Unprocessed Meat
The type of meat mattered. Those who ate more unprocessed meat (such as fresh cuts of beef, pork or chicken) had a noticeably lower risk of dying from any cause.
Why This Matters
If these results hold true, diet plans could become much more personal. People who know they have a high‑risk APOE gene might protect their brains simply by choosing the right foods.
Study Limits
The research is observational, which means it can show a link but not prove cause and effect. Randomized clinical trials are needed to test whether changing meat intake directly reduces dementia risk.
About the APOE Gene
APOE comes in three common forms: ε2, ε3 and ε4. Everyone inherits two copies, one from each parent, creating six possible combos (2/2, 2/3, 2/4, 3/3, 3/4, 4/4). Compared with the most common 3/3 combo, having one ε4 copy raises Alzheimer’s risk three‑ to four‑fold; two copies raise it ten‑ to fifteen‑fold. The ε2 version is linked to a lower risk.