Impact of dietary polyphenols on human platelet function – A critical review of controlled dietary intervention studies

Abstract

Cardiovascular disease is a chronic disease influenced by many factors, with activated blood platelets being one of them. Platelets play a central role in the formation of plaques within blood vessels, contributing to early inflammatory events. Consumption of diets rich in plant-based products protects against the development of cardiovascular disease. Polyphenols, which are secondary plant metabolites found in a wide range of foodstuffs and beverages, may be partially responsible for these effects. Their protective properties include inhibitory effects on platelet function in vitro and in vivo. However, the bioavailability of many polyphenols is poor and it is unclear whether sufficient quantities can be obtained by dietary means to exert protective effects. Consequently, this review summarizes 25 well-controlled human intervention studies examining the effect of polyphenol-rich diets on platelet function. These studies report a huge variety of research methods, study designs, and study subjects, resulting in controversial assertions. One consistent finding is that cocoa-related products, however, have platelet-inhibiting effects when consumed in moderate amounts. To assess whether other classes of dietary polyphenols, or their metabolites, also beneficially affect platelet function requires more well-controlled intervention studies as well as the adoption of more uniform methods to assess platelet aggregation and activation.

Evidence for a protective effect of polyphenols-containing foods on cardiovascular health: an update for clinicians

“…The physiological relevance of the beneficial effects on platelets of an exposure to flavanols from cocoa consumption (equivalent to 100 g of dark chocolate with 70% cocoa solids) has been estimated to be comparable to standard doses of aspirin (~80 mg) clinically used as antiaggregant therapy [Pearson et al 2002]. However, chronic intake of polyphenols from berries (whole fruits or juices) may result in only a relatively low inhibition of platelet aggregation under shear stress [Ostertag et al 2010]. Other fruit juices such as orange juice, grapefruit juice and sea buckthorn juice taken daily for 7-10 days in healthy volunteers failed to reduce ex vivo platelet activity [Eccleston et al 2002;Keevil et al 2000].…”

“…In parallel, the promotion of dietary therapies providing consistent inhibition of platelet function could be of interest. Based on epidemiological studies suggesting that diets rich in flavonoids can reduce the risk of arterial thrombosis [Arts and Hollman, 2005], it seems interesting to investigate the ability of these bioactives to inhibit platelet activation.Considering the impact of polyphenols-rich diets on human platelet function, a recent critical review has to be considered with attention [Ostertag et al 2010]. This review summarized 25 well-controlled human intervention trials and revealed a wide heterogeneity between studies as for levels of polyphenol intake (18.6 mg to 2.20 g/ day), study population (healthy, increased risk factors and/or clinical disease), study size (between 6 and 1535 subjects), length of supplementation (acute intake for 1 day to chronic intake for over 90 days) and variety of tests used to assess platelet function.…”

The role of quercetin in membrane stability

“…It is difficult to presume, from a relatively small number of well designed and controlled human trials, how polyphenols improve the cardio-vascular function or the glucose homeostasis (Ostertag et al 2010;Alexandru et al 2012). Clinical studies which investigate the potential role of polyphenols in health and disease are difficult to design, as long-term studies are interfered by the treatment and the evolution of the disease.…”

“…Still, even if authors state that additional larger, longerduration and extensive trials are required to confirm the exact mechanism of cardiovascular benefits comong from polyphenols and their effects on glucose homeostasis and adipose tissue, incorporating plant foods that are rich in flavanols in the diet of healthy individuals could help to reduce cardio-vascular risk (Ostertag et al 2010;Alexandru et al 2012). …”

Bioactive Chromone Derivatives – Structural Diversity

“…Regarding prostate cancer, however, the results obtained by these researchers for this particular chromone analogue do not support a protective effect [30], which reflects selectivity, another relevant feature of the anticancer protective activity of this kind of systems. Additionally, dietary polyphenols were shown to possess beneficial cardiovascular effects [31,32].…”