Evidence Hub

Quercetin reduces markers of oxidative stress and inflammation in sarcoidosis

Boots AW, Drent M, de Boer VC, Bast A, Haenen GR

Clinical nutrition (Edinburgh, Scotland), 2011

12 participants · 247 citations

Abstract

BACKGROUND & AIMS: Oxidative stress and low antioxidant levels are implicated in the aetiology of sarcoidosis, an inflammatory disease. Quercetin is a potent dietary antioxidant that also displays anti-inflammatory activities. Consequently, the aim is to examine the effect of quercetin supplementation on markers of oxidative stress and inflammation in sarcoidosis.

METHODS: A double-blind intervention study has been conducted with two groups of non-smoking, un-treated sarcoidosis patients, matched for age and gender. One group was given 4x500 mg quercetin (n = 12) orally within 24 h, the other one placebo (n = 6). Plasma malondialdehyde levels were used as marker of oxidative damage, plasma ratios of TNFα/IL-10 and IL-8/IL-10 as pro-inflammatory markers.

RESULTS: Quercetin supplementation improved the antioxidant defence, indicated by the increased total plasma antioxidant capacity. Moreover, quercetin supplementation also reduced markers of oxidative stress and inflammation in the blood of sarcoidosis patients. The effects of quercetin supplementation appeared to be more pronounced when the levels of the oxidative stress and inflammation markers were higher at baseline.

CONCLUSIONS: Sarcoidosis patients might benefit from the use of antioxidants, such as quercetin, to reduce the occurring oxidative stress as well as inflammation. The effects of long-term use of antioxidant supplementation in sarcoidosis, using e.g. quercetin, on improvement of lung function remain to be…

How strong is the evidence?

Evidence Hub reads this as a randomized trial, done in people. Its evidence level is 3 of 5 (Moderate · trial / cohort / secondary analysis). Trials without a large randomized design, cohorts and secondary analyses give moderate evidence. Reported size: 12 participants or records.

How the five levels of evidence work. The level is assigned automatically from the abstract and can be wrong, so check the paper.

Read the paper

Related studies

Go deeper in Evidence Hub

Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.

Open this study Sign up free