par Poortmans, Jacques ;Francaux, Marc
Référence Science & sports, 14, 6, page (271-277)
Publication Publié, 1999-11
Article révisé par les pairs
Résumé : Objectives. - For the last six years the consumption of exogenous creatine monohydrate has been extended more and more. Despite numerous publications on the ergogenic effects of this naturally occurring substance, there is almost no information on the deleterious effects of this supplement. The objectives of this review are to point out facts which are often in contradiction with allegations introduced by the media. Topics. - In athletes, exogenous creatine supplements amount to 20 g per day during five days followed by 1 to 10 g per day, every day, for weeks, months; and even years. Usually consumers do not report side-effects, with the exception of body weight increase. However, gastro-intestinal disturbances and muscle cramps have been reported occasionally. Liver and kidney dysfunction have also been hypothesized but real facts are missing for this. From a theoretical point of view, exogenous creatine supplementation suppresses its hepatic synthesis (maximum 2 g per day for vegetarians). Its destination is mainly (95-98%) skeletal muscle and all excess is excreted in urine (on average 60% of the supplement). Scientific publications on the undesirable effects of exogenous creatine are almost non-existent, but newspapers and the media do not hesitate to publish false information or wrong interpretations based on one individual case of an individual with nephropathy who, later on, consumed creatine monohydrate. In addition, we did not find any sideeffects on renal function after short-term (five days), medium-term (nine weeks) or long-term (up to five years) creatine supplementation in small cohorts of athletes. Future prospects. - We have no intention to validate or not the supplementation of exogenous creatine by athletes, but apparently there are no real deleterious effects on the body of healthy consumers. Nevertheless, one has to be careful about individual reactions when excess food are taken up. We are convinced that regular biological check-ups are needed to avoid any abnormal reaction under creatine supplementation.