CATEGORY: BRAIN & MENTAL HEALTH
Adults who consumed at least 7 grams of olive oil a day—roughly half a tablespoon—had a 28% lower risk of dying from dementia over 28 years than those who rarely or never used it, according to a large US study.1
How the Study Worked
Researchers tracked 92,383 US health professionals—women in the Nurses’ Health Study and men in the Health Professionals Follow-Up Study—who were free of heart disease and cancer at the start. Every four years, participants reported their diet, including olive oil, on detailed food questionnaires. Over 28 years and more than 2.1 million person-years, 4,751 people died from causes related to dementia, a progressive decline in memory and thinking severe enough to disrupt daily life. Deaths were identified from death records, and the analysis adjusted for lifestyle, health, and genetic factors.
Replacing Other Fats
The link between olive oil and lower dementia-related death held regardless of a person’s overall diet quality. In additional modeling, swapping about 5 grams a day of margarine or mayonnaise for the same amount of olive oil was associated with an 8% to 14% lower risk of dementia-related death, while swapping other vegetable oils or butter showed no clear benefit. People carrying two copies of the APOE ε4 gene variant—the strongest common genetic risk factor for Alzheimer’s—were far more likely to die with dementia, but the olive oil association remained after accounting for it.
What the Findings Do and Don’t Show
This was an observational study, so it shows an association between olive oil and lower dementia-related death, not proof that olive oil prevents dementia. People who use olive oil may share other brain-protective habits. If you have questions about your own dementia risk or family history, your health care provider is the right person to guide you.
Key Takeaways
- Consuming at least half a tablespoon of olive oil daily was associated with a 28% lower risk of dementia-related death.
- The link held even after accounting for overall diet quality and a major Alzheimer’s risk gene.
- This is an association, not proof; discuss your personal risk with your health care provider.
References
- Tessier AJ, Cortese M, Yuan C, et al. Consumption of olive oil and diet quality and risk of dementia-related death. JAMA Network Open. 2024;7(5):e2410021. link.