Guaraná and caffeine
Guaraná contains caffeine, the stimulant found in coffee, tea, yerba mate, colas and chocolate. “Guaraná also contains a whole mix of other compounds that act together to stimulate you over and above itscaffeine content,” says Professor Stephen Myers, Director of NatMed-Research at Southern Cross University. In fact, at the University of Tasmania a study comparing the effects of coffee, guaraná and yerba mate showed that guaraná produced the greatest alertness and improvement in the performance of mental tasks. Coffee produced a peak in alertness after about 30-45 minutes then rapidly fell away, while the effects of guaraná were still continuing – and increasing – after 150 minutes. “There might be substances in guaraná that delay the metabolism of caffeine or slows the absorption of caffeine to prolong its effect,” Professor Myers explains.
Another study at Northumbria University in England showed that guaraná’s positive effects on mood, memory and cognitive function don’t all come down to caffeine levels. Researchers found that better results came from doses of guaraná that had 37.5 or 75mg of caffeine compared to doses that contained 150 or 300mg of caffeine (an espresso shot has about 80mg of caffeine, a can of V 109mg). Melbourne’s Swinburne University of Technology also looked at how people performed at a range of mental tasks after taking guaraná. In these tests, the guaraná was weaker again with a measly 9mg of caffeine, so researchers concluded that the improvements with guaraná were unlikely to come from its caffeine content.
Guaraná and energy drinks
“There’s a trend now for putting what I call ‘marketing doses’ of a herb in a product,” says Prof. Myers. “They have it on the label, but it’s not actually enough to do anything.” While the marketing hype suggests that guaraná puts the kick in energy drinks, there is nothing to prove that guaraná has any effect on physical stamina or performance. In fact, any “buzz” is more likely to come from additional caffeine extract pumped into them, along with ergogenic herbs such as panax ginseng, which can increase the effects of caffeine. By contrast, the Brazilian soft drink Guaraná Antarctica is not marketed as an energy drink and has no warnings on the label. It contains guaraná extract, but unlike common energy drinks in Australia, it has no added caffeine or other stimulants, and it has less caffeine in it than Coca-Cola (30mg per can).
Healthy or hazardous?
Like other forms of caffeine, guaraná may interact with certain medications, and too much guaraná carries all the risks associated with high levels (over 300mg) of caffeine – insomnia, trembling, anxiety, dehydration and palpitations. Unlike coffee, however, laboratory tests have shown no evidence of toxicity even in large doses, but guaraná should be avoided during pregnancy and lactation, or when there is high blood pressure. Amazonian Indians used guaraná for bowel complaints, and now we know that the herb’s high tannin levels make it good for mild diarrhea. In Peru, guaraná is popular for treating cellulite and localised fat – there’s not much clinical evidence behind this yet, although the herb is widely accepted as an appetite suppressant.
The trouble is that when guaraná comes mixed with lots of other things in a canned drink or a ‘herbal’ energy pill, you don’t really know what you’re getting. “Unscrupulous companies use very low quality herbs or they’ll use part of the plant that’s not actually active,” says Professor Myers. For best results, he suggests going to a herbalist who will give you the real deal in the form of a liquid extract or a powder that you mix with hot water like coffee.