Safety profile of caffeine and 1,3-dimethylamylamine supplementation in healthy men

Abstract

Caffeine and 1,3-dimethylamylamine (DMAA) are widely used alone and in combination with dietary supplements. No investigation has determined the safety profile of chronic intake of caffeine or DMAA, alone or in combination, within the same study design. A total of 50 young and healthy men completed 12 weeks of daily supplementation with either a placebo ( n = 11), caffeine at 250 mg day−1 ( n = 14), DMAA at 50 mg day−1 ( n = 13), or caffeine at 250 mg day−1 + DMAA at 50 mg day−1 ( n = 12). Before and after 6 and 12 weeks of supplementation, the following variables were measured: body mass/composition, resting respiratory rate, blood pressure, 12-lead electrocardiogram, urinalysis, complete blood count, metabolic panel, lipid panel, and oxidative stress, inflammatory, and cardiac biomarkers. No interaction effects were noted for any variable ( p > 0.05), with little change occurring across time for subjects in any of the four conditions. With the exception of urinary pH ( p = 0.05; Pre (6.5 ± 0.1) higher than week 6 (6.1 ± 0.1)) and blood CO2 ( p = 0.02; week 12 (25.9 ± 0.3 mmol L−1) higher than week 6 (24.8 ± 0.3 mmol L−1)), no time effect was noted for any other variable ( p > 0.05). These data indicate that 12 weeks of daily supplementation with caffeine and DMAA, alone or in combination, does not result in a statistically significant change in any of the measured outcome variables.