Intake Duration of Anthocyanin-Rich New Zealand Blackcurrant Extract Affects Metabolic Responses during Moderate Intensity Walking Exercise in Adult Males

We examined effects of intake duration of anthocyanin-rich New Zealand blackcurrant (NZBC) extract on physiological and metabolic responses during moderate intensity walking. Healthy men (n = 16, age: 24 +/- 6 years, body mass: 78 +/- 16 kg, BMI: 24.7 +/- 4.1 kg center dot m(-2), body fat: 15 +/- 5%) volunteered. One metabolic equivalent (1-MET: 3.95 +/- 0.64 ml center dot kg(-1)center dot min(-1)) was measured during supine rest. Responses during the 30-min walk (n = 3: 4-MET;n = 13: 5-MET) (speed: 5.7 +/- 0.7 km center dot hr(-1)) were measured at 7-10, 17-20 and 27-30 min and averaged over the time periods. For intake conditions (7-days and 14-days), two capsules of NZBC extract (600 mg containing 210 mg of anthocyanins) were taken with breakfast (14-day washout). The final two capsules were ingested 2-hr before the morning walk. Intake duration of NZBC extract had no effect on heart rate, minute ventilation, oxygen uptake, and carbon dioxide production. Fat oxidation was enhanced with 7- and 14-day intake by 11 +/- 19% and 17 +/- 26% (baseline: 0.36 +/- 0.12, 7-day: 0.39 +/- 0.13, 14-day: 0.41 +/- 0.13 g center dot min(-1),p = 0.007). Only 14-day intake lowered RER (baseline: 0.852 +/- 0.046, 7-day: 0.843 +/- 0.045, 14-day: 0.837 +/- 0.037,p = 0.019) and carbohydrate oxidation (baseline: 0.95 +/- 0.40, 7-day: 0.91 +/- 0.40, 14-day: 0.86 +/- 0.33 g center dot min(-1),p = 0.032). Rating of perceived exertion was lower with 7-day and 14-day intake (baseline: 11.0 +/- 2.3, 7-day: 10.5 +/- 1.8, 14-day: 10.3 +/- 2.1,p = 0.002). Longer intake duration (i.e. 14 days) of New Zealand blackcurrant extract seems to enhance fat oxidation more during a 30-min moderate intensity walk than 7 days intake. The intake duration of anthocyanin-rich New Zealand blackcurrant extract may be due to an enhanced bioavailability of anthocyanin-derived metabolites that alter the mechanisms for substrate oxidation during moderate intensity exercise.

Automated summary

This study demonstrated that a longer intake duration (i.e. 14 days) of anthocyanin-rich New Zealand blackcurrant extract enhanced fat oxidation during a 30-minute moderate intensity walk, compared to 7 days intake. The intake duration may influence substrate oxidation mechanisms during exercise, with 14-day intake showing greater improvements in fat oxidation, lower RER, and reduced carbohydrate oxidation compared to 7-day intake.