Part II: The Power of Polyphenols
A large body of evidence shows that daily consumption of EVOO can significantly reduce the risk of cardiovascular disease (CVD). Part I of this two-part series highlighted the contributions of oleic acid (OA). The other bioactive components of EVOO that protect against CVD are its more than 30 polyphenols.
Factors that contribute to CVD include oxidative stress, inflammation, cholesterol, blood-vessel function, and high blood pressure (hypertension). Below, we’ll look closely at the mechanisms by which polyphenols work in the body to modify and improve these factors.
What are polyphenols? Polyphenols are naturally occurring substances in many plants and fungi. Most polyphenols are antioxidants, which means they help neutralize chemical compounds formed in the body that can damage cells. Hydroxytyrosol (HT) has been identified as the polyphenol in EVOO that is essential in the prevention of CVD.
HT combats oxidative stress
Oxidative stress can cause cell mutations and has been identified as an underlying cause of multiple aspects of CVD. Injured tissues release ions—charged particles—that bind to oxygen, creating an excess of unstable molecules. As an antioxidant, HT directly neutralizes these unstable molecules, or reactive oxygen species (ROS). HT has also been shown to inhibit the cell damage produced by ROS and to enhance the antioxidant abilities of cells in the blood vessel walls.
Lowers inflammation
HT can block some of the processes that signal for cells to mount an inflammatory response. In this way, HT reduces the impact of inflammatory substances that are linked to oxidative stress as well as to impaired blood vessel function, a key risk factor for CVD.
Reduces “bad” cholesterol and improves “good”
Polyphenols reduce the amount of small molecules of LDL (“bad” cholesterol), which do the most damage. Polyphenols also help prevent LDL from forming plaques that build up in the arteries,
or atherosclerosis. In a 3-week clinical trial, HDL (“good” cholesterol) functioning improved significantly in healthy patients who consumed high-polyphenol EVOO, compared with low-polyphenol EVOO.
Protects the blood vessel lining and lowers blood pressure
Polyphenols help prevent damage to the endothelium, the inner lining of the blood vessel walls, by increasing the production of nitric oxide (NO), a vasodilator—a substance that relaxes the blood vessels. By enhancing the production of NO, polyphenols can improve endothelial function, protect against arterial stiffness, and lower blood pressure.
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