Tutkimukset

Quercetin in berries reduces blood pressure

Quercetin is a flavonol that is classified as an antioxidant and has natural antihistamine properties. Many wild berries, such as bog whortleberry, cranberry and sea buckthorn berry, contain high amounts of quercetin (Fig. 1).

Figure 1. Quercetin content of wild berries. Source: Määttä-Riihinen, K., Kamal-Eldin, A., Mattila, P., González-Paramás, A. & Törrönen, R. (2004): Distribution and contents of phenolic compounds in eighteen Scandinavian berry species. Journal of Agricultural and Food Chemistry 52: 4477-4486.

Earlier studies have found a positive correlation between intake of quercetin and reduced incidence of cardiovascular diseases. However, the evidence regarding the effects of quercetin on blood pressure has not been conclusive. Therefore, controlled studies investigating the effects of quercetin on blood pressure were identified. Meta-analysis was performed using either a fixed-effect or random-effect model according to I² statistic. Altogether, 7 trials comprising 9 treatment arms (587 patients) were found.

The results of meta-analysis showed significant reductions both in systolic and diastolic blood pressure following supplementation with quercetin. Studies were categorized according to the quercetin dose. There was a significant blood pressure reducing effect in studies with doses ≥ 500 mg/day. The recommended dietary allowance of total flavonoids is nowadays between 250-400 mg/day. A diet rich in berries, vegetables and fruits will ensure the sufficient quercetin intake.

Source: Serban, MC., Sahebkar, A., Zanchetti, A., Mikhailidis, D., Howard, G., Antal, D., Andrica, F., Ahmed, A., Aronow, W., Muntner, P., Graham, I., Wong, N., Rysz, J., Banach, M. (2016): Effects of quercetin on blood pressure: a systematic review and meta-analysis of randomized controlled trials. Journal of the American Heart Association, doi: 10.1161/JAHA.115.002713.

Text:
Anni Koskela, Arctic Flavours Association
anni.koskela@arctic-flavours.fi
+358 40 164 6177