Anthocyanin-rich New Zealand blackcurrant extract reduces treadmill running-induced gastrointestinal symptoms in the heat: pilot observations

Abstract

We examined the effect of anthocyanin-rich New Zealand black-currant (NZBC) extract on running-induced gastrointestinal symp-toms in the heat. Recreationally active men (n = 12, age: 28 ± 6 yr,BMI: 24.5 ± 1.8 kg·m−2, _VO2max: 56 ± 6 mL·kg−1·min−1) volunteered.Participants dosed with 7 days of NZBC extract (CurraNZ®) (210 mganthocyanins) or placebo. Exercise consisted of treadmill runningfor one hr at 65% _VO2max (34.1 ± 0.1°C, 40.8 ± 0.2% relative humidity)with the recording of gastrointestinal symptoms during and at60 min following recovery in normal conditions. With placebo, 11participants (92%) reported gastrointestinal symptoms (e.g. belch-ing, stitch), and this was reduced to four participants (25%) withNZBC extract. Using a modified visual analog scale, the accumu-lated score of gastrointestinal symptoms was lower with 7-dayintake of NZBC extract (placebo: 112, NZBC extract: 54, p = 0.04).The prevalence of upper, lower and other gastrointestinal symp-toms was reduced (upper, placebo: 75%, NZBC extract: 25%; lower:placebo: 25%, NZBC extract: 17%; other, placebo: 50%, NZBCextract: 25%). With placebo, only two participants reported severesymptoms (one participant for dizziness and nausea with thatparticipant still reporting those in the NZBC extract condition).Seven-day intake of New Zealand blackcurrant extract reducedthe incidence of gastrointestinal symptoms during 1-h of runningin hot environmental conditions. Future research should examinethe efficacy of NZBC extract on exercise-associated gastrointestinalsymptoms in conditions in which gastrointestinal symptoms can be expected to be severe