Biochemistry of blood platelet activation and the beneficial role of plant oils in cardiovascular diseases

The main function of blood platelets is to form hemostatic plugs and enable thrombosis. These properties, however, can be greatly influenced by dietary components which may inhibit certain steps of platelet activation, including platelet aggregation. Such inhibition can play a role in the prophylaxis and treatment of cardiovascular diseases associated with blood platelet hyperactivation. In fact, plant and fish oils have been identified and specifically used for this purpose. Numerous in vivo and in vitro experiments have explored the potential use of these oils to inhibit platelet activation as well as their role in reducing oxidative stress and blood pressure, and lowering triglyceride and cholesterol. This chapter presents and compares the anti-platelet effects of fish and plant oils and their constituents, especially fatty acids. Studies on healthy subjects and patients with various cardiovascular diseases are also examined. Findings indicate that both fish and plant oils contain protective components with anti-platelet activity having clearly defined mechanisms of action. Although both are excellent sources of omega fatty acids and vitamins, plant oils contain components with cardioprotective benefit in hypercholesterolemics, i.e., phytosterols. Plant oils may hence play a key role in strategies for preventing and treating cardiovascular diseases associated with platelet hyperactivation. Further studies are clearly needed to determine the precise dose of these components needed for effective prophylaxis and treatment.

Omega-3 and omega-6 polyunsaturated fatty acids and metabolic syndrome: A systematic review and meta-analysis

BACKGROUND & AIMS

Previous studies suggest that polyunsaturated fatty acids (PUFAs) may reduce the risk of metabolic diseases, but some have shown ambiguous results. The aim of this study was to systematically evaluate and summarize available evidence on the association between omega-3 and omega-6 PUFA levels and risk of metabolic syndrome (MetS).

METHODS

A systematic literature search of articles published until December 2017 was conducted in PubMed, Web of Science, and Cochrane Library databases. Meta-analyses of the highest vs. lowest categories of omega-3 and omega-6 PUFAs were conducted using the random effects models.

RESULTS

Thirteen studies (2 case-control, 9 cross-sectional, 1 nested case-control, and 1 prospective cohort) with 36,542 individuals were included. Higher omega-3 PUFA levels in diets or blood were associated with a 26% reduction in the risk of MetS (odds ratio (OR)/relative risk (RR) 0.74, 95% confidence interval (CI) 0.62-0.89). This inverse association was evident among studies with Asian populations (OR/RR 0.69, 95% CI 0.54-0.87), but not among those with American/European populations (OR/RR 0.84, 95% CI 0.55-1.28). Null results were found regarding the association between circulating/dietary omega-6 PUFAs and MetS.

CONCLUSION

The present meta-analysis indicates that higher intakes of omega-3 PUFAs, but not omega-6 PUFAs, was associated with lower MetS risk; adding to the current body of evidence on the metabolic health effects of circulating/dietary omega-3 PUFAs.