Clinical trial ties olive oil's anti-inflammatory effects to the genetic influences of its antioxidants, which occur abundantly only in extra virgin grade oils
by Craig Weatherby
Nutrigenomics is the fast-growing study of how whole foods and specific nutrients affect the “expression” of the genes that direct activities of our cells.
Now, the authors of a Spanish clinical trial report that the antioxidants in extra virgin grade olive oil exerted beneficial effects on 98 genes responsible for regulating inflammation.
These exciting results suggest that these compounds benefit cardiovascular health via their nutrigenomic effects, rather than their antioxidant impacts.
Why is EV olive oil heart-healthy? It’s the polyphenols, not the fats
Olive oil has long been thought heart-healthy, based on the results of large epidemiological (diet-health) studies.
And it was long presumed that these heart benefits flowed from the monounsaturated fat (oleic acid) abundant in olive oil… but that hypothesis hasn’t withstood subsequent scrutiny.
Instead, the positive cardiovascular impacts of olive oil are clearly tied to the polyphenol-class antioxidants in olives (Perez-Jimenez F et al. 2005; Ruano J et al. 2007).
Polyphenols are the primary beneficial compounds in some fruits (berries, grapes, plums), cocoa, tea, coffee, beans, whole grains, and certain vegetables.
Test tube experiments show that the special polyphenol antioxidants in olives—a very rare kind called tyrosols—are extraordinarily good at neutralizing the unstable, cell-damaging oxygen compounds called free radicals.
Only extra virgin (unrefined) olive oil is rich in tyrosols and other polyphenols, which are much scarcer in virgin grade (semi-refined) oils and virtually absent from cheap, refined olive oils.
This distinction is believed to explain why—unlike the two lesser grades—only extra virgin olive oil has been shown to enhance arterial health, which has been partially linked to the body’s “antioxidant status.”
However, absorption studies in humans suggest that on average, only a very small proportion of dietary polyphenols actually make it into the bloodstream.
And the average amounts of dietary polyphenols people absorb are believed too small to raise the body’s antioxidant status by a substantial, lasting extent.
So the apparent ability of extra virgin olive oil to enhance arterial health and reduce undesirable inflammation probably has little to do with its polyphenols’ antioxidant powers.
Instead, the new clinical evidence from Spain shows that the polyphenols in olives exert beneficial “nutrigenomic” effects on many of the genes responsible for starting, moderating, and ending inflammation.
This is a critically important finding because silent, diet- and lifestyle-induced inflammation is proven to trigger, maintain, and/or worsen all of major chronic diseases… everything from cancer, arthritis, and cardiovascular disease to diabetes and dementia.
Extra virgin olive oil curbs expression of 98 pro-inflammatory genes
Researchers from the University of Cordoba studied 20 people with metabolic syndrome… a cluster of signs that’s closely linked to increased risk of diabetes and cardiovascular disease (Camargo A et al. 2010).
The volunteers ate breakfast foods that included either extra virgin olive oil (high in polyphenols), or virgin grade oil (low in polyphenols).
Compared to those who ate the breakfast featuring virgin grade oil, the expression of 79 pro-inflammatory genes was much lower in those who ate the breakfast with extra virgin olive oil.
And, the expression of 19 anti-inflammatory genes was much higher in those who ate the breakfast with extra virgin olive oil.
As in prior clinical studies, these results demonstrated a “dose-response” link between the levels of polyphenols in the two grades of oil and their very different impacts on genes… which proves that these compounds are the active anti-inflammatory factors in olive oil.
(See “Extra Virgin Olive Oil Confirmed as Best Cardiac Prevention Choice.”)
Many of the 98 genes affected beneficially by the extra virgin oil are also associated with increased risk of cardiovascular disease and diabetes, probably due to their pro-inflammatory effects.
Among the genes affected were several linked to key molecular drivers of inflammation, such as Nf-kappa B, AP-1, cytokines, and omega-6 fatty acids… factors that will be familiar to folks who’ve read Nicholas Perricone, M.D.’s scientifically sharp anti-aging books.
As the Spanish team wrote, “These results provide at least a partial molecular basis for the reduced risk of cardiovascular disease observed in Mediterranean countries, where [extra] virgin olive oil represents the main source of dietary fat” (Camargo A et al. 2010).
So bypass that cheap olive oil in favor of extra virgin grade. It’s far healthier, and tastes much better, too!
- Camargo A, Ruano J, Fernandez JM, Parnell LD, Jimenez A, Santos-Gonzalez M, Marin C, Perez-Martinez P, Uceda M, Lopez-Miranda J, Perez-Jimenez F. Gene expression changes in mononuclear cells from patients with metabolic syndrome after acute intake of phenol-rich virgin olive oil. BMC Genomics. 2010 Apr 20;11(1):253. [Epub ahead of print]
- Jiménez-Gómez Y, López-Miranda J, Blanco-Colio LM, Marín C, Pérez-Martínez P, Ruano J, Paniagua JA, Rodríguez F, Egido J, Pérez-Jiménez F. Olive oil and walnut breakfasts reduce the postprandial inflammatory response in mononuclear cells compared with a butter breakfast in healthy men. Atherosclerosis. 2009 Jun;204(2):e70-6. Epub 2008 Sep 17.
- Perez-Jimenez F et al. International conference on the healthy effect of virgin olive oil. Eur J Clin Invest. 2005 Jul;35(7):421-4. Review.
- Ruano J, López-Miranda J, de la Torre R, Delgado-Lista J, Fernández J, Caballero J, Covas MI, Jiménez Y, Pérez-Martínez P, Marín C, Fuentes F, Pérez-Jiménez F. Intake of phenol-rich virgin olive oil improves the postprandial prothrombotic profile in hypercholesterolemic patients. Am J Clin Nutr. 2007 Aug;86(2):341-6.