Influence of polyphenolic compounds on human health and the course of a number of diseases

The purpose of this literature review is to elucidate the biological effects of polyphenols and their importance for human health. Polyphenols play the role of food antioxidants and are of growing interest in various fields of scientific research and including nutritional research due to the presence of these compounds in plant foods. In this review, a brief classification of polyphenols is presented. Polyphenols include a diverse group of compounds such as phenolic acids, flavonoids, stilbenes and lignans. Flavonoids are found in fruits such as apples, apricots, grapes and citrus fruits; vegetables are rich in phenolic acids. Polyphenols are also rich in nuts, legumes, green tea, blueberries, cocoa. Polyphenols are of interest because of their effective direct and indirect antioxidant mechanisms for attenuating chronic diseases, as well as leveling negative lifestyle and nutritional factors. The antioxidant properties of polyphenolic compounds limit oxidative stress, which is relevant in geriatrics. Through a diet enriched with polyphenols, it is possible to reduce the likelihood of developing cancer, and diabetes. The favorable effect of polyphenols is noted on the functioning of the cardiovascular system. Polyphenols protect the endothelium from damage, slow the formation of atherosclerotic plaques, exhibit antithrombotic action. Having antioxidant activity, polyphenols inhibit lipoperoxidation processes, having a therapeutic effect in Alzheimer's and Parkinson's disease. In particular, catechins are effective in Parkinson's disease and ferulic acid is effective in patients with Alzheimer's disease. The protective effects of polyphenols associated with their antioxidant activity make the use of these compounds in geriatrics attractive. Due not only to their antioxidant but also hypoglycemic properties, polyphenols may be an additional treatment for diabetes mellitus. The polyphenols theaflavins and thearubigins, found in black tea and possessing antioxidant properties, have anti-cancer effects. Polyphenols also protect the skin from sun damage. It can be concluded that patients with chronic diseases should be prescribed a diet rich in polyphenols.