Study Spotlight

Study Spotlight

Can an Apple a Day (or Apple Extract) Keep High Blood Pressure at Bay?

According to the Centers for Disease Control and Prevention (CDC), 1 in every 3 adults in America has high blood pressure.

One of the keys to overcoming this potentially deadly condition, or preventing its onset, is to expand blood vessels and arteries so that blood flows more easily and with less pressure. This process is called “vasodilation” and it something than many natural compounds are uniquely qualified to do.

In a clinical study, adult volunteers who were either on the cusp of having high blood pressure, or had mild hypertension tested either an apple supplement standardized for polyphenol compounds or a placebo for four weeks. While the results were fairly low-key, there were initial improvements in the apple polyphenol group for one measure of vasodilation. It will be interesting to see how these compounds would work in combination with other polyphenols, like those from grape seed, that are known to have cardioprotective and blood pressure reducing effects in further studies.



Saarenhovi M, Salo P, Scheinin M, et al. The effect of an apple polyphenol extract rich in epicatechin and flavan-3-ol oligomers on brachial artery flow-mediated vasodilatory function in volunteers with elevated blood pressure. Nutr J. 2017 Oct 27;16(1):73.

BACKGROUND: The primary aim of this study was to test the hypothesis that an orally ingested apple polyphenol extract rich in epicatechin and flavan-3-ol oligomers improves endothelium-dependent brachial artery flow-mediated vasodilatation (FMD) in volunteers with borderline hypertension. The secondary aim of the study was to test whether the investigational product would improve endothelium-independent nitrate-mediated vasodilatation (NMD).

METHODS: This was a single center, repeated-dose, double-blind, placebo-controlled, crossover study in 60 otherwise healthy subjects (26 men, 34 women; aged 40-65 years) with borderline hypertension (blood pressure 130-139/85-89 mmHg) or un-medicated mild hypertension (blood pressure 140-165/90-95 mmHg). The subjects were randomized to receive placebo or the apple polyphenol extract to provide a daily dose of 100 mg epicatechin for 4 weeks, followed by a four to five-week wash-out period, and then 4 weeks intake of the product that they did not receive during the first treatment period. FMD and NMD of the left brachial artery were investigated with ultrasonography at the start and end of both treatment periods, and the per cent increase of the arterial diameter (FMD% and NMD%) was calculated.

RESULTS: With the apple extract treatment, a significant acute improvement was detected in the mean change of maximum FMD% at the first visit 1.16 (p = 0.04, 95% CI: 0.04; 2.28), last visit 1.37 (p = 0.02, 95% CI: 0.22; 2.52) and for both visits combined 1.29 (p < 0.01, 95% CI: 0.40; 2.18). However, such improvement was not statistically significant when apple extract was compared with placebo. The overall long-term effect of apple extract on FMD% was not different from placebo. No statistically significant differences between the apple extract and placebo treatments were observed for endothelium-independent NMD.

CONCLUSIONS: A significant acute improvement in maximum FMD% with apple extract administration was found. However, superiority of apple extract over placebo was not statistically significant in our study subjects with borderline hypertension or mild hypertension. The study raised no safety concerns regarding the daily administration of an apple polyphenol extract rich in epicatechin.

Link to complete article: The effect of an apple polyphenol extract rich in epicatechin and flavan-3-ol oligomers on brachial artery flow-mediated vasodilatory function in volunteers with elevated blood pressure

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