Methylxanthines, namely caffeine, theobromine and theophylline are found
in several beverages and food products such as coffee, cocoa, tea and cola drinks.
These substances can provide benefits to humans but also prove harmful mainly when
consumed in high amounts. However, the beneficial and deleterious effects of
methylxanthines are controversial in research findings, largely because of
inconsistencies within research conducted and factors associated within studies. For
instance, some authors have reported methylxanthines could have potential antioxidant
activity under physiological conditions but opposing studies do not support these
claims. Factors that influence the effects of methylxanthines include age, gender and
health status of the individual. In addition to these, other factors such as doses,
consumption of drugs or pharmaceuticals, alcohol and tobacco habits and diet also play
a role in methylxanthine effects and metabolism. Therefore, our review is to provide a
clearer understanding of the beneficial/adverse effects of methylxanthines in humans.
A description of the physiological and toxicological effects of these methylxanthines is
provided.
Keywords: Bioactive compounds, Caffeine, Human health and risks,
Methylxanthines, Theobromine, Theophylline.