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

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

JAMA Network Open

May 6, 2024; Vol. 7; No. 5; Article e2410021

Anne-Julie Tessier, PhD; Marianna Cortese, PhD; Changzheng Yuan, ScD; Kjetil Bjornevik, PhD; Alberto Ascherio, DrPH; Daniel D.Wang, MD, ScD; Jorge E. Chavarro, ScD; Meir J. Stampfer, DrPH; Frank B. Hu, PhD; Walter C. Willett, DrPH; Marta Guasch-Ferr, PhD. The authors are from Harvard School of Public Health; Zhejiang University School of Medicine, China; the University of Copenhagen, Denmark. This study cites 37 references.

This is a prospective cohort study from the Nurses’ Health Study. Of the 92,383 participants, 60,582 (66%) were women and the mean age was 56 years. The follow-up period was for 28 years, totaling 2,183,095 person-years.

The objective of this study was to determine if the long-term consumption of olive oil was associated with dementia-related death. Olive oil intake was assessed every 4 years and categorized as:

• Never or less than once per month
• Greater than 7 g/d = 1⁄2 tablespoon
• Greater than 0 to less than or equal to 4.5 g/d
• Greater than 4.5 g/d to less than or equal to 7 g/d

The variables the authors adjusted for included weight, smoking, alcohol, physical activity, multivitamin use, menopausal status, postmenopausal hormone use, family history of dementia, consumption of soda-butter-mayonnaise-other vegetable oils-margarine-red meat-fruits-vegetables-nuts-whole grains-trans-fat, history of hypercholesterolemia, apolipoprotein ε4 (APOE ε4), and history of diabetes.

1 tablespoon of olive oil is considered to be 13.5 g.

KEY POINTS FROM THIS ARTICLE:

1) Age-standardized dementia mortality rates have been on the rise in the past 20 years.

2) “One-third of older adults die with Alzheimer disease or another dementia.”

3) “Olive oil may exert anti-inflammatory and neuroprotective effects due to its high content of monounsaturated fatty acids and other compounds with antioxidant properties such as vitamin E and polyphenols.”

4) “Olive oil consumption may lower dementia mortality by improving vascular health.”

5) “Several clinical trials support the effect of olive oil in reducing CVD via improved endothelial function, coagulation, lipid metabolism, oxidative stress, platelet aggregation and decreased inflammation.”

6) In 2022, these authors “showed that olive oil consumption was associated with a lower risk of total and cause-specific mortality in large US prospective cohort studies, including a 29% lower risk for neurodegenerative disease mortality in participants who consumed more than 7 g/d of olive oil compared with little or none.”

7) “The apolipoprotein E ε4 (APOE ε4) allele is known to interfere with lipid and glucose metabolism such that it increases the risk of dementia.”

• “Individuals who were homozygous for the apolipoprotein ε4 (APOE ε4) allele were 5 to 9 times more likely to die with dementia.”

8) Findings:

• “Those with the highest olive oil intake (>7 g/d) had the lowest dementia-related death risk compared with those with minimal intake (never or less than once per month), regardless of diet quality.”
• “Consuming at least 7 g/d of olive oil [1⁄2 tablespoon] was associated with a 28% lower risk of dementia-related death compared with never or rarely consuming olive oil; results were consistent after further adjustment for APOE ε4.

9) Conclusions and Recommendations:

• “In US adults, higher olive oil intake was associated with a lower risk of dementia-related mortality, irrespective of diet quality.”
• “Replacing 5 g/d of margarine and mayonnaise with the equivalent amount of olive oil was associated with an 8% to 14% lower risk of dementia mortality.”
• “Beyond heart health, the findings extend the current dietary recommendations of choosing olive oil and other vegetable oils for cognitive-related health.”
• Olive oil intake represents a strategy to reduce dementia mortality risk.
• “Olive oil intake may be protective of dementia and related mortality, particularly in women.”

10) “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.” [Key Point]

• “Substituting olive oil intake for margarine and mayonnaise was associated with lower risk of dementia mortality and may be a potential strategy to improve longevity free of dementia.”

11) These findings provide evidence to support dietary recommendations advocating for the use of olive oil as a potential strategy to maintain overall health and prevent dementia. [Important]

• “This highlights a potentially specific role for olive oil.”

12) Mild cognitive impairment, Alzheimer’s disease, and related dementias are associated with abnormal blood brain barrier permeability, allowing the crossing of neurotoxic molecules into the brain.

• “[The] phenolic compounds in olive oil, particularly extra-virgin olive oil, may attenuate inflammation, oxidative stress and restore blood brain barrier function, thereby reducing brain amyloid-β and tau-related pathologies and improving cognitive function.”

13) Strengths of this analysis include Our cohort analyses include the long follow-up period, the large sample size, including included genotyping of the APOE ε4 allele, and inclusion of a large number of co-variables.

We have reviewed these articles also showing health benefits from olive oil consumption:

Article Review 29-05:
Ibuprofen-like Activity in Extra-virgin Olive Oil

Article Review 20-22:
Consumption of Olive Oil and Risk of Total and Cause-Specific Mortality Among U.S. Adults