expert opinion

Using nutrigenomics to uncover how the potent antioxidant properties of hydroxytyrosol can reduce the risk of cardiovascular disease

November 1, 2015

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Professor Francesco Visioli, Department of Molecular Medicine, University of Padova, Italy

Francesco Visioli is Professor of Human Nutrition in the Department of Molecular Medicine at the University of Padova, Italy. He is also Assistant Professor at the College of Pharmacy, Oregon State University. Professor Visioli’s current research concerns essential fatty acids, namely those of the omega-3 variety as well as a series of natural antioxidants, in relation to their ability to reduce the risk ofatherosclerosis and cardiovascular disease. In recent work (1), he has investigated the biological and pharmacological properties of olive oil phenolics, including hydroxytyrosol.

The beneficial effects of olives in the diet to cardiovascular health can be largely attributed to the phenolic compound hydroxytyrosol. The European Food Safety Authority (EFSA) permits a health claim that specifies phenolic compounds derived from olives (including hydroxytyrosol) provide protection of low-density lipoprotein (LDL) from oxidation (2). Whilst it can be shown that hydroxytyrosol is a potent antioxidant, Professor Visioli believes that its mode of action is likely to be much more specific. The fact that a food contains antioxidant ingredients, does not in it itself confer any proven health benefits.

In 2004, Weinbrenner et al. (3) conducted a small trial that demonstrated that short-term consumption of olive oil decreased plasma oxidized LDL and increased HDL cholesterol in a dose-dependent manner with the phenolic content of the administered olive oil.

Professor Visioli has shown that consumption of hydroxtyrosol in nutritionally relevant amounts is able to positively modulate the glutathione-driven antioxidant enzymatic machinery in the adipose tissue (1). This is important because adipose tissue plays an important role in cardiometabolism and its physiopathology. He is now investigating which metabolites of hydroxytyrosol could achieve this modified enzyme action.

At present, the current knowledge of the mode of action of olive hydroxytyrosol is limited to its inhibition of thromboxane B2 production by serum, leading to a possible prevention of thrombotic and micro-thrombotic processes (4).

References

  1. Giordano, E., Dávalos, A, & Visioli, F; “Chronic hydroxytyrosol feeding modulates glutathione-mediated oxido-reduction pathways in adipose tissue: a nutrigenomic study”; Nutrition, Metabolism, and Cardiovascular Diseases 2014, 24(10): 1144–50. doi:10.1016/j.numecd.2014.05.003
  2. EFSA NDA Panel; “Scientific Opinion on the substantiation of health claims related to polyphenols in olive and protection of LDL particles from oxidative damage”; EFSA Journal 2011; 9(4): 2033.
  3. Weinbrenner, T., Torre, R. De, Saez, G. T., Rijken, P., Tormos, C., & Coolen, S.; “Olive Oils High in Phenolic Compounds Modulate Oxidative / Antioxidative Status in Men”; Human Nutrition and Metabolism 2004; 1, (April): 2314–2321.
  4. Crespo, M. C., Tomé-Carneiro, J., Burgos-Ramos, E., Loria Kohen, V., Espinosa, M. I., Herranz, J., & Visioli, F.; “One-week administration of hydroxytyrosol to humans does not activate Phase II enzymes”;. Pharmacological Research: The Official Journal of the Italian Pharmacological Society 2015, 95-96C, 132–137. doi:10.1016/j.phrs.2015.03.018& Coolen, S. (2004).