Olive Oil

Olive Oil

  • Food & Drink
  • Updated August 21, 2016

Olive oil is a major component of the Mediterranean diet, often used in salad dressings or as cooking oil. It is available in a variety of commercial grades and its contents (e.g., monounsaturated fats and phenolic compounds) vary depending on the olive variety, the picking season and growing environment, and other factors. Evidence suggests olive oil is safe and might confer slight cognitive benefits as part of a healthy diet.

Evidence

Although olive oil is a component of other healthy interventions (such as the Mediterranean diet), few studies have examined the benefits specifically of olive oil. Our search found:

• 0 meta-analyses or systematic reviews
• 1 randomized controlled trial (with results from multiple trial sites)
• 2 observational studies
• Multiple preclinical studies

Potential Benefit

A randomized controlled trial of older adults at risk of cardiovascular disease compared a low-fat diet to the Mediterranean diet supplemented with either extra-virgin olive oil or nuts. Over four years, the people assigned to the Mediterranean diet supplemented with extra-virgin olive oil showed a slight, but significant, cognitive improvement. The results were not consistent for protection from mild cognitive impairment or dementia [2-5]. Two observational studies also reported that olive oil was associated with slightly improved cognitive function [6][7].

These studies suggest that olive oil may slightly promote cognitive fitness. However, in the randomized controlled trial, the Mediterranean diet plus olive oil group was significantly different from the low-fat group but not from the Mediterranean diet plus nuts group. In other words, the best evidence to-date is not for olive oil alone but for the Mediterranean diet, which typically includes olive oil.

APOE4 carriers:

In one clinical trial, a Mediterranean diet intervention appeared to benefit both APOE carriers and non-carriers [12]. For more information on what the APOE4 gene allele means for your health, read our APOE4 information page.

For Dementia Patients

No clinical research has studied whether olive oil can benefit patients with dementia.

Safety

Studies of olive oil have reported no significant adverse effects, although excessive olive oil consumption may result in mild temporary diarrhea [13]. Though olive oil is one of the safer cooking oils, when heated past its smoke point, it may release volatile organic compounds and lose some of its beneficial content [14][15].

NOTE: This is not a comprehensive safety evaluation or complete list of potentially harmful drug interactions. It is important to discuss safety issues with your physician before taking any new supplement or medication.

How to Use

Olive oil is widely available in varying grades and qualities. Components of olive oil (e.g., oleuropein, oleocanthal) are also available as supplements. The exact dose that may provide cognitive benefit is unknown. Extra virgin olive oil may be more beneficial than refined olive oil because of its increased beneficial phenolic content [17]. Olive oil is a pure fat and therefore should not be consumed in excess.

References

  1. Olive Oil Source (accessed 11/04 2016)
  2. Valls-Pedret C, Sala-Vila A, Serra-Mir M et al. (2015) Mediterranean Diet and Age-Related Cognitive Decline: A Randomized Clinical Trial. JAMA Intern Med 175, 1094-1103.
  3. Valls-Pedret C, Lamuela-Raventos RM, Medina-Remon A et al. (2012) Polyphenol-rich foods in the Mediterranean diet are associated with better cognitive function in elderly subjects at high cardiovascular risk. J Alzheimers Dis 29, 773-782.
  4. Martinez-Lapiscina EH, Clavero P, Toledo E et al. (2013) Mediterranean diet improves cognition: the PREDIMED-NAVARRA randomized trial. Journal of neurology, neurosurgery, and psychiatry 84, 1318-1325.
  5. Martinez-Lapiscina EH, Clavero P, Toledo E et al. (2013) Virgin olive oil supplementation and long-term cognition: the PREDIMED-NAVARRA randomized, trial. J Nutr Health Aging 17, 544-552.
  6. Bajerska J, Wozniewicz M, Suwalska A et al. (2014) Eating patterns are associated with cognitive function in the elderly at risk of metabolic syndrome from rural areas. Eur Rev Med Pharmacol Sci 18, 3234-3245.
  7. Berr C, Portet F, Carriere I et al. (2009) Olive oil and cognition: results from the three-city study. Dementia and geriatric cognitive disorders 28, 357-364.
  8. Farr SA, Price TO, Dominguez LJ et al. (2012) Extra virgin olive oil improves learning and memory in SAMP8 mice. Journal of Alzheimer's disease : JAD 28, 81-92.
  9. Qosa H, Mohamed LA, Batarseh YS et al. (2015) Extra-virgin olive oil attenuates amyloid-beta and tau pathologies in the brains of TgSwDI mice. J Nutr Biochem 26, 1479-1490.
  10. Grossi C, Rigacci S, Ambrosini S et al. (2013) The polyphenol oleuropein aglycone protects TgCRND8 mice against Ass plaque pathology. PloS one 8, e71702.
  11. Arunsundar M, Shanmugarajan TS, Ravichandran V (2015) 3,4-dihydroxyphenylethanol attenuates spatio-cognitive deficits in an Alzheimer's disease mouse model: modulation of the molecular signals in neuronal survival-apoptotic programs. Neurotoxicity research 27, 143-155.
  12. Martinez-Lapiscina EH, Galbete C, Corella D et al. (2014) Genotype patterns at CLU, CR1, PICALM and APOE, cognition and Mediterranean diet: the PREDIMED-NAVARRA trial. Genes Nutr 9, 393.
  13. Drugs.com (2009) Olive Oil (accessed 02/21/16 2016)
  14. Allouche Y, Jimenez A, Gaforio JJ et al. (2007) How heating affects extra virgin olive oil quality indexes and chemical composition. J Agric Food Chem 55, 9646-9654.
  15. Katragadda HRF, Andres; Sidhu, Sukh; Carbonell-Barrachina, Angel A (2010) Emissions of volatile aldehydes from heated cooking oils. Food Chemistry 120, 59-65.
  16. WebMD (2009). Olive Side Effects and Safety (accessed 02/18/16 2016)
  17. Owen RW, Mier W, Giacosa A et al. (2000) Phenolic compounds and squalene in olive oils: the concentration and antioxidant potential of total phenols, simple phenols, secoiridoids, lignansand squalene. Food Chem Toxic 38, 647-659.