Vitamin C Supplementation Attenuates the Increases in Circulating Cortisol, Adrenaline and Anti-Inflammatory Polypeptides Following Ultramarathon Running

Abstract

The effects of vitamin C supplementation on the alterations in the circulating concentrations of cortisol, adrenaline, interleukin-10 (IL-10) and interleukin-1 receptor antagonist (IL-1Ra) which accompany ultramarathon running were measured using immuno-chemiluminescence, radioimmunoassay and ELISA procedures. Forty-five participants in the 1999 Comrades 90 km marathon were divided into equal groups (n = 15) receiving 500 mg/day Vit C (VC-500), 1500 mg/day Vit C (VC-1500) or placebo (P) for 7 days before the race, on the day of the race, and for 2 days following completion. Runners recorded dietary intake before, during and after the race and provided 35 ml blood samples 15 - 18 hrs before the race, immediately post-race, 24 hrs post race and 48 hrs post-race. Twenty-nine runners (VC-1500, n = 12; VC-500, n = 10; P, n = 7) complied with all study requirements. All post-race concentrations were adjusted for plasma volume changes. Analyses of dietary intakes and blood glucose and anti-oxidant status on the day preceding the race and the day of the race did not reveal that carbohydrate intake or plasma vitamins E and A were significant confounders in the study. Mean pre-race concentrations of serum vitamin C in VC-500 and VC-1500 groups (128 +/- 31 and 153 +/- 34 micromol/l) were significantly higher than in the P group (83 +/- 39 micromol/l). Immediate post-race serum cortisol was significantly lower in the VC-1500 group (p < 0.05) than in P and VC-500 groups. When the data from VC-500 and P groups was combined (n = 17), immediate post-race plasma adrenaline, IL-10 and IL-1Ra concentrations were also significantly lower (p < 0.05) in the VC-1500 group. The study demonstrates an attenuation, albeit transient, of both the adrenal stress hormone and anti-inflammatory polypeptide response to prolonged exercise in runners who supplemented with 1500 mg vitamin C per day when compared to < or = 500 mg per day.

Nutritional modulation of exercise-induced immunodepression in athletes: a systematic review and meta-analysis

“…No effect Peters et al (2001a) 29; 90 km Comrades Marathon 500 mg/day vit C vs 1500 mg/ day vit C vs placebo for 7 days before the race, on the day of the race, and for 2 days following completion…”

“…Four studies (Nieman et al, 2000b(Nieman et al, , 2002bPeters et al, 2001a, b), all including ultramarathon runners, addressed the effect of vitamin C supplementation on cortisol. Two studies (Nieman et al, 2000b;Peters et al, 2001a) referred to the same subjects and Figure 1 Systematic review flow chart summary.…”

“…Vitamin C intake had inconsistent effects on plasma increases of IL-6, IL-10, IL-1ra and IL-8. Doses of 1500 mg of vitamin C daily were reported to attenuate the increase in these cytokines after exercise (Nieman et al, 2000b;Peters et al, 2001a) or have no effect (Nieman et al, 2002b) at lower doses of 1000 or 500 mg daily (Nieman et al, 1997b;Peters et al, 2001b). Of the two studies where glutamine was given as a supplement, one study showed glutamine to augment the increase of plasma IL-6 (Hiscock et al, 2003) after exercise, while the other (Castell et al, 1997) did not.…”

“…In the study of Peters et al (2001a), vitamin C had a significant effect on cortisol in ultramarathon runners when ingested in a dose greater than or equal to 1000 mg/day for 7 days before race and 2 days after. In the study of Nieman et al (2002b), 1500 mg of vitamin C daily for the 7 days preceding the race had no effect on cortisol.…”

Physical activity, immunity and infection

“…Vitamin C supplementation ( ‡ 1000 mg/d) augmented the increase in lymphocyte counts after exercise, attenuated the serum cortisol increase in ultramarathon runners and attenuated the increase of inflammatory cytokines (131)(132)(133)(134)(135) . No significant differences in the self-reported incidence of URTI after exercise have been found when the subjects consumed 1000 mg vitamin C daily for 2 months prior to and 1 month after the marathon (136) .…”