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Citrus Bioflavonoids Extract

Also known as: Hesperidin, Naringin, Diosmin, Eriocitrin, Polymethoxylated flavones, Citrus flavonoids, Citrus polyphenols, Citrus bioflavonoid complex

Overview

Citrus bioflavonoids are a class of polyphenolic compounds found abundantly in citrus fruits like oranges, lemons, and grapefruits, particularly in their peels. Key members include hesperidin, naringin, diosmin, and eriocitrin. These compounds are investigated for their potential cardiovascular benefits, including improving endothelial function and modulating lipid metabolism. Research suggests that citrus bioflavonoids may exert antioxidant and anti-inflammatory effects. While generally considered safe, their bioavailability is limited unless processed to enhance absorption. They are available in various supplement forms, often standardized extracts, and are sometimes combined with vitamin C to improve stability. Moderate research supports their use, with numerous RCTs and meta-analyses, though more long-term human trials are needed to fully establish their efficacy and safety.

Benefits

Citrus bioflavonoids primarily benefit endothelial function, showing a 2.75% absolute improvement in flow-mediated dilation (FMD) compared to placebo. This effect is supported by consistent RCT data. Preclinical studies suggest they may reduce total cholesterol, triglycerides, and LDL levels, but human trials have yielded mixed results. Secondary benefits include antioxidant activity through free radical scavenging and improved insulin sensitivity. The most significant evidence is found in overweight/obese and dyslipidemic populations, indicating they may be particularly beneficial for individuals with these conditions. A dose-response meta-analysis indicates a linear relationship between dosage and FMD improvement.

How it works

Citrus bioflavonoids exert their effects through several key mechanisms. They activate the NO-cGMP pathway, leading to vasodilation and improved endothelial function. Additionally, they modulate PPAR-α/γ, influencing lipid metabolism. Their anti-inflammatory effects are attributed to NF-κB inhibition. However, the bioavailability of citrus bioflavonoids is generally low, with less than 10% absorption unless they are enzymatically modified. Peak plasma concentrations are typically reached within 2-4 hours after ingestion. These compounds interact with various body systems to promote cardiovascular health and metabolic balance.

Side effects

Citrus bioflavonoids are generally recognized as safe (GRAS). Common side effects are rare at dosages below 500mg/day. Some individuals may experience mild gastrointestinal distress, such as upset stomach, at higher doses (above 1g/day), but this is uncommon (1-3%). There is a theoretical risk of interaction with CYP3A4 substrates, and limited evidence suggests potential interactions with anticoagulants. Individuals with citrus allergies should avoid citrus bioflavonoid supplements. While generally safe, it's important to be aware of potential drug interactions and to monitor for any adverse effects, especially at higher dosages.

Dosage

The minimum effective dose of citrus bioflavonoids for improving endothelial function is around 200mg/day. An optimal dosage range is between 500-1000mg/day, ideally split into multiple doses. Short-term use up to 2g/day has been shown to be safe. Micronized or glycoside-conjugated forms are preferred due to their enhanced absorption. Co-administration with vitamin C may enhance the stability of citrus bioflavonoids. It's advisable to start with a lower dose and gradually increase it to assess tolerance. Consult with a healthcare professional to determine the most appropriate dosage based on individual health status and needs.

FAQs

How long until results appear?

Improvements in flow-mediated dilation (FMD) can typically be observed within 4-12 weeks of consistent use.

Best time to take?

It is recommended to take citrus bioflavonoids with meals containing fats to enhance absorption.

Difference from vitamin C?

Citrus bioflavonoids and vitamin C have distinct mechanisms of action. While they can work synergistically, they are not interchangeable.

Research Sources

https://pubmed.ncbi.nlm.nih.gov/38561995/ – A dose-response meta-analysis of 8 RCTs (n=596) found a linear dose-response relationship between citrus bioflavonoid intake and flow-mediated dilation (FMD), with each 200mg/day increment associated with a 1.09% increase in FMD. The study noted high heterogeneity among the included trials, suggesting variability in the effects of citrus bioflavonoids across different populations and formulations.
https://www.frontiersin.org/journals/pharmacology/articles/10.3389/fphar.2022.822678/full – A preclinical meta-analysis of 23 animal studies indicated that citrus bioflavonoids significantly reduced lipid levels, including total cholesterol, triglycerides, and LDL. However, the authors noted that these findings have limited translation to human studies, highlighting the need for further clinical trials to confirm these effects in humans.
https://journals.lww.com/jno/fulltext/2023/03000/impact_of_citrus_fruit_and_hesperidin_intake_on.3.aspx – An umbrella review of 22 meta-analyses found that citrus fruit and hesperidin intake were associated with a reduced risk of all-cause mortality (RR=0.90, 95% CI: 0.85-0.95). The review included observational data, which may limit the strength of the conclusions, but suggests a potential protective effect of citrus bioflavonoids on overall health and longevity.
https://pmc.ncbi.nlm.nih.gov/articles/PMC6431442/ – This review discusses the antioxidant and anti-inflammatory properties of citrus flavonoids, highlighting their potential to scavenge free radicals and inhibit inflammatory pathways like NF-κB. It also mentions the low bioavailability of many citrus flavonoids, emphasizing the importance of formulation strategies to enhance absorption and efficacy.
https://examine.com/research-feed/study/dnxZP0/ – This study provides an overview of the effects of hesperidin on vascular function. It highlights the potential of hesperidin to improve endothelial function and reduce blood pressure, contributing to overall cardiovascular health.