LONG-TERM consumption of olive oil is associated with a significantly lower risk of dementia-related death, regardless of overall diet quality. The research, conducted by Anne-Julie Tessier, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA, and colleagues, which spanned nearly three decades, suggests that olive oil could play a crucial role in dietary strategies aimed at reducing dementia mortality.
Conducted by examining data from the Nurses’ Health Study (NHS) and the Health Professionals Follow-Up Study (HPFS) between 1990–2018, the study involved 92,383 participants who were free of cardiovascular disease and cancer at the outset (65.6% female; mean age: 56.4 years; predominantly non-Hispanic White participants). Olive oil intake was assessed every 4 years using a food frequency questionnaire, and participants were categorised based on their consumption levels.
The authors founds that individuals who consumed >7 g of olive oil daily (about half a tablespoon) had a 28% lower risk of dementia-related death compared to those who rarely or never consumed olive oil (adjusted hazard ratio [aHR]: 0.72; 95% confidence interval [CI] 0.64–0.81; P <0.001). Subgroup analyses revealed that this association was significant for females (aHR: 0.67; 95% CI: 0.59–0.77), but not males (aHR: 0.87; 95% CI: 0.69–1.09). Results remained consistent even after adjusting for apolipoprotein ε4 gene status, for which homozygosity increases the likelihood of dementia-related death by 5–9 times.
Interesting, the protective benefits of olive oil were independent of overall diet quality, as measured by the Alternative Healthy Eating Index (AHEI) and Mediterranean Diet Score (MDS). The study also found that replacing 5 g of margarine or mayonnaise per day with the same amount of olive oil was associated with an 8–14% lower risk of dementia mortality. However, similar substitutions for other vegetable oils or butter did not show significant effects.
“Current dietary guidelines regarding fats are mainly based on evidence related to cardiovascular health,” stated Tessier. This study extends current dietary recommendations of choosing olive oil over other fats to the context of cognitive-related health and dementia mortality.
Reference:
Tessier A et al. Consumption of olive oil and diet quality and risk of dementia-related death. JAMA Netw Open. 2024;7(5):e241002.
