Citrus Fruits, Olive Polyphenols and Flavanones Reduce Cardiovascular Disease Risk

Written by Angeline A. De Leon, Staff Writer. Supplementation with a mixture of grapefruit, bitter orange fruits, and olive leaf extracts may potentially lessen the risk of cardiovascular disease.

Although advances in medicine have helped to significantly reduce mortality rates of cardiovascular disease (CVD) ¹, the increased prevalence of diabetes and obesity in recent years ² contributes to the perpetuation of CVD’s status as the leading cause of death ³. Today, preventative measures against CVD involve lifestyle changes and dietary modifications ⁴, although the specific role of micronutrient intake is still being explored. Epidemiological research has linked flavonoids and polyphenols (found in fruits and vegetables) to a range of biological activities that may help prevent CVD, including antioxidant, anti-inflammatory, and vasodilatory effects ^5,6. Supplementation with the phenolic components of olive oil, for example, can improve lipid profile and biomarkers of oxidative stress ⁷, while flavonoid-rich foods, such as cocoa, tea, and citrus fruits, are associated with blood pressure-lowering effects and improvement of endothelial function ⁸. In the same way that pharmaceutical treatment of CVD has explored combining multiple active pharmaceutical ingredients (polypills) ⁹, it is possible that a dietary formulation blending various flavonoids and polyphenols could produce a similar protective effect for vascular health. A 2020 study ¹⁰ in Nutrients looked at the efficacy of a food supplement containing flavones, flavanones, and polyphenols (sourced from grapefruit, bitter orange, and olive extracts) in reducing biomarkers of CVD risk.

A total of 96 healthy Caucasian subjects (53 men, 43 women; mean age = 49.3 years) were enrolled in a randomized, double-blind, placebo-controlled, parallel-group trial in which they were assigned to consume 1000 mg of the active product (containing 250-300 mg of flavanone-glycosides, 175-200 mg of flavones, and 85-90 mg of olive polyphenols) or matching placebo daily for 8 weeks. At baseline and at Week 8, anthropometric measurements and blood pressure (BP) were taken, and cardiovascular risk was assessed by measuring flow-mediated vasodilation (FMD) of the brachial artery (measure of endothelial function). Fasting venous blood samples were also obtained and analyzed to determine lipid profile, biomarkers of oxidative stress, and inflammatory biomarkers.

Over a period of 8 weeks, supplementation with the proprietary nutritional product was seen to significantly improve FMD (p = 0.039) and diastolic BP (p = 0.045), as compared to placebo. Significant relative improvement of total cholesterol (p = 0.001) and low-density lipoprotein (LDL) cholesterol (p = 0.02) was apparent as well. In terms of biomarkers related to oxidative stress and inflammation, at the end of the study, a number of parameters showed significant improvement, relative to placebo: LDL-oxidase (p < 0.001), ratio of oxidized to reduced glutathione (GSH/GSSH ratio) (p = 0.003), protein carbonyl (p = 0.012), and interleukin-6 (IL-6) 6 (p < 0.001). No significant between-group differences, however, were evident for anthropometric variables.

Evidence from the study points to favorable effects associated with regular intake of a nutritional supplement combining flavones, flavanones, and polyphenols from citrus fruits and olive extract. Supplementation with the nutraceutical blend over a period of 8 weeks was found to improve a number of CVD-related factors, including endothelial function, blood pressure, lipid profile, and biomarkers associated with oxidative stress and inflammation. The combination of various bioactive ingredients in the natural supplement investigated here appears to exert a synergistic effect that can clinically lower CVD risk in healthy individuals. However, the particular underlying mechanisms involved deserve further study. Potential limitations should be considered when interpreting results, including the study’s relatively small sample size and its short follow-up period. It would also be important to replicate findings in clinical populations with existing CVD conditions and/or those with increased risk of it.

Source: Macarro MS, Rodriguez JPM, Morell EB, et al. Effect of a combination of citrus flavones and flavonones and olive polyphenols for the reduction of cardiovascular disease risk: an exploratory randomized, double-blind, placebo-controlled study in healthy subjects. Nutrients. 2020; 12: 1475. DOI: 10.3390/nu12051475.

© 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).

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Posted June 16, 2020.

Angeline A. De Leon, MA, graduated from the University of Illinois at Urbana-Champaign in 2010, completing a bachelor’s degree in psychology, with a concentration in neuroscience. She received her master’s degree from The Ohio State University in 2013, where she studied clinical neuroscience within an integrative health program. Her specialized area of research involves the complementary use of neuroimaging and neuropsychology-based methodologies to examine how lifestyle factors, such as physical activity and meditation, can influence brain plasticity and enhance overall connectivity.

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