GASTROINTESTINAL DISTRESS AFTER CREATINE
SUPPLEMENTATION IN ATHLETES: ARE SIDE
EFFECTS DOSE DEPENDENT?
Zlatko Ahmetovic Research in Sports Medicine, 16: 15–22, 2008
The main aim of the present study was to investigate the effects of two
different creatine-supplementation protocols on incidence of gastrointestinal
(GI) distress in top-level athletes. Data were collected from 59 toplevel
male soccer players who were allocated in a double-blind design to
three randomly assigned trials: ingesting creatine supplement (C5: 2 × 5-g
doses, and C10: 1 × 10-g dose) or placebo (P) for 28 days. In order to
assess potential side effects of the supplementation regimen, all subjects
were instructed to report any adverse effects of supplementation on their
GI system. Survey questions covered perceived side effects on GI system
linked with creatine supplementation. In all three treatment groups, the
most frequent GI complaints were diarrhoea (39.0%), stomach upset
(23.8%), and belching (16.9%). We did not find a significant difference
between incidence of GI distress symptoms between C5 and the placebo
group after the survey. Yet, significant differences were found for incidence
of diarrhoea between the C5 and C10 groups (28.6% vs. 55.6%,
respectively, p < 0.05). Moreover, diarrhoea was more frequent in the C10
group as compared with the placebo group (55.6% vs. 35.0%, p < 0.05).
There is no reason to believe that short-term oral creatine supplementation
for 28 days has any detrimental effect on the GI tract if taken in a
recommended amount (10 g per day in two equal doses). The risk of diarrhoea
may be increased, however, following intake of 10 grams of creatine
per single serving.
