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Effect of alpha-linolenic acid in combination with the flavonol quercetin on markers of cardiovascular disease risk in healthy, non-obese adults: A randomized, double-blinded placebo-controlled crossover trial

Constanze Burak, S. Wolffram, B. Zur, P. Langguth, R. Fimmers, B. Alteheld, P. Stehle, S. Egert

Nutrition (Burbank, Los Angeles County, Calif.), 2019

67 participants · 39 citations

Abstract

OBJECTIVES

Alpha-linolenic acid (ALA) and quercetin are characteristic compounds in plant-based diets. Cardioprotective effects have been described for both substances, although a possible benefit of combining ALA and quercetin has not, to our knowledge, been evaluated yet. The aim of this study was to investigate the potential independent and additive effects of ALA and quercetin on blood pressure (BP) and lipid and glucose metabolism, as well as on biomarkers of inflammation, oxidative stress, and antioxidant status in healthy, non-obese men and women. Another aim was to examine whether chronic supplementation of supranutritional doses of quercetin would result in an accumulation of plasma quercetin concentration over time.

METHODS

In a double-blinded, placebo-controlled crossover trial, healthy volunteers were randomized to receive 3.6 g/d ALA plus 190 mg/d quercetin or placebo for 8 wk. Data from 67 individuals (34 men, 33 women, mean age: 24.6 y) were assessed.

RESULTS

Plasma quercetin, tamarixetin, isorhamnetin, and kaempferol increased significantly from baseline to study end with ALA + quercetin but not with ALA + placebo. No significant effect on office systolic BP, mean 24 h ambulatory BP (ABP), or mean daytime ABP was seen in either study group. Both interventions significantly decreased total cholesterol, low-density lipoprotein cholesterol, non-high-density lipoprotein cholesterol, and apolipoprotein B to a similar extent. No effect on high-density lipoprotein…

How strong is the evidence?

Evidence Hub reads this as a randomized trial, done in people. Its evidence level is 2 of 5 (High · randomized trial). Randomized trials of a reasonable size are the strongest single-study design. Reported size: 67 participants or records.

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