BACKGROUND AND PURPOSE:

• Tessier et al. (JAMA Network Open, 2024) examined the association of olive oil intake with the subsequent risk of dementia-related death and assessed the joint association with diet quality and substitution for other fats

METHODS:

• Prospective cohort study
  • Nurses’ Health Study (NHS; 1990 to 2018)
  • Health Professionals Follow-Up Study (HPFS; 1990 to 2018)
• Participants
  • Women and men who were free of cardiovascular disease and cancer at baseline
• Exposures
  • Olive oil intake, assessed every 4 years using a food frequency questionnaire
    • Never, or <1x per month
    • >0 to ≤4.5 g/d
    • >4.5 to <7 g/d
    • >7 g /d
  • Diet quality
    • Assessed with the Alternative Healthy Eating Index and Mediterranean Diet score
• Study design
  • Multivariable Cox proportional hazards regressions were used to estimate hazard ratio (HR)
  • Adjusted for confounders: Genetic | Sociodemographic | Lifestyle factors
• Primary outcome
  • Dementia-related mortality

RESULTS:

• 92,383 participants
  • Women: 65.6%
  • Mean age: 56.4 (SD, 8.0) years
  • 28 years of follow-up (2,183,095 person-years)
• Dementia-related deaths: 4751
  • Individuals who were homozygous for the apolipoprotein ε4 (APOE ε4) allele were 5 to 9 times more likely to die with dementia
• Compared with never or rarely consuming olive oil, consuming at least 7 g/d of olive oil was associated with a lower risk of dementia-related death
  • Overall: Adjusted pooled HR 0.72 (95% CI, 0.64 to 0.81)
  • Women: Adjusted pooled HR 0.67 (95% CI, 0.59 to 0.77) 
  • Men: adjusted pooled HR 0.87 (95% CI, 0.69 to 1.09)
• Results were consistent after adjustment for APOE ε4
• There was no interaction by diet quality score
• In modeled substitution analyses, replacing 5 g/d of margarine and mayonnaise with the equivalent amount of olive oil was associated with lower risk of dementia mortality
  • Margarine: 8% (95% CI, 4 to 12)
  • Mayonnaise: 14% (95% CI, 7 to 20)
• Substitutions for other vegetable oils or butter were not significant

CONCLUSION:

• A higher intake of olive oil was associated with a reduced risk of dementia-related mortality regardless of diet quality
• The authors state

This study found that in US adults, particularly women, consuming more olive oil was associated with lower risk of dementia-related mortality, regardless of diet quality

These findings extend the current dietary recommendations of choosing olive oil and other vegetable oils to the context of cognitive health and related mortality

Learn More – Primary Sources:

Consumption of Olive Oil and Diet Quality and Risk of Dementia-Related Death