/mineral /guarana (300 mg) and ginseng (100 mg) and another included study used a supplement of guarana complex (37.5 mg of guarana + 12.5 mg ginseng +22.5 mg vitaminC). Comparisons were made with multivitamin supplements, caffeine extract, carbohydrates, ginseng or placebo.
The included studies used various methods to assess the effects of the intervention on cognition, and thus, heterogeneity of methods across studies was present. Two studies used the Cognitive Drug Research (CDR) computerized assessment battery and two studies used the Cognitive Demand Battery. One study