This randomized, double-blind, placebo-controlled trial evaluated among 25 participants the effects of 14 days of daily supplementation with either 50 mg of oligomerized-polyphenol from Litchi chinensis fruit extract (OPLFE) or mixed plant extract (310 mg of butcher’s broom extract, ginkgo biloba extract, vinca minor extract, zinc yeast, passion flower extract, ginseng extract, myrciaria dubia fruit juice, black cohosh extract, guarana, enzyme-treated asparagus extract and calcium stearate) with 50 mg of OPLFE, or placebo on cold sensitivity and skin temperature.

Changes in skin temperature and peripheral blood flow of the middle finger were assessed immediately before and 1, 5, 10, 20, and 30 min after immersion in cold water (10 masculineC). Skin temperature and blood flow in peripheral tissue increased in the OPLFE and mixed plant extract with OPLFE groups on day 14 compared with those on day 1. In addition, cold sensitivity in these two groups significantly improved between day 1 and day 14.

In conclusion, these findings suggest that OPLFE improves cold sensation-particularly in the lower extremities by increasing peripheral blood flow and skin temperature.

Waki H, Suzuki T, Uebaba K, Hisajima T. Effects of a Standardized Oligomerized-Polyphenol from Litchi chinensis Fruit Extract and Mixed Plant Extract Supplementation on Peripheral Circulation and Cold Sensitivity. J Nutr Sci Vitaminol (Tokyo). 2020;66(3):255-260.

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