Application and safety concerns of Guarana
Guarana is a plant. It is named for the Guarani tribe in the Amazon, who used its seeds to brew a drink. The colour of the fruit ranges from brown to red and it contains black seeds that are partly covered by white arils. The colour contrast when the fruit is split open has been compared with the appearance of eyeballs and has become the basis of an origin myth among the Sateré-Mawé people.Today, guarana seeds are still used as medicine.
As a dietary supplement or herb, guarana seed is an effective stimulant:it contains about twice the concentration of caffeine found in coffee seeds (about 2–4.5% caffeine in guarana seeds, compared to 1–2% for coffee seeds).The additive has gained notoriety for being used in energy drinks. As with other plants producing caffeine, the high concentration of caffeine is a defensive toxin that repels herbivores from the berry and its seeds.
People take guarana by mouth for obesity, athletic performance, mental performance, to increase energy, as an aphrodisiac, and for many other conditions, but there is no good scientific evidence to support these uses. Guarana can also be unsafe when taken long-term in large amounts.
The effectiveness ratings for GUARANA are as follows:
Insufficient evidence to rate effectiveness for...
Anxiety. Early research shows that taking a product containing hawthorn, black horehound, passionflower, valerian, cola nut, and guarana can reduce anxiety in some people. It is not clear if guarana alone is beneficial.
Lack of appetite in people with cancer. Early research shows that taking guarana extract slightly improves appetite and prevents weight loss in people with cancer who have lost their appetite and are losing weight. But the benefit is very small.
Tiredness in people treated with cancer drugs. Some research shows that taking guarana can reduce feelings of tiredness in some people undergoing chemotherapy. But conflicting results exist.
Improving memory and thinking skills (cognitive function). Early research in healthy people shows that taking a single dose of guarana extract can improve thinking speed and some aspects of memory. However, other research shows that taking guarana does not improve mental function in adults or older people.
Athletic performance. Research shows that taking a single dose of a product containing guarana, B vitamins, vitamin C, and minerals improves exercise tolerance in trained athletes by a very small amount. It is not clear if guarana alone is beneficial.
Obesity. Taking guarana along with mate and damiana seems to increase weight loss.
Feelings of well-being. Early research shows that taking guarana does not improve feelings of well-being in healthy individuals.
Serious illness caused by radiation exposure. Research shows that taking guarana does not improve symptoms of depression or tiredness in people undergoing radiation treatment.
Guarana contains caffeine. Caffeine works by stimulating the central nervous system (CNS), heart, and muscles. Guarana also contains theophylline and theobromine, which are chemicals similar to caffeine.
About safety concerns
When taken by mouth: Guarana is LIKELY SAFE for most adults when taken in amounts commonly found in foods. When taken by mouth in medicinal amounts for a short time, guarana is POSSIBLY SAFE.
When taken by mouth in high doses for a long time, guarana is POSSIBLY UNSAFE. Guarana contains caffeine. Doses containing more than 400 mg of caffeine daily have been linked to side effects. Side effects depend on the dose. At typical doses, the caffeine in guarana can cause insomnia, nervousness and restlessness, stomach irritation, nausea, vomiting, increased heart rate and blood pressure, rapid breathing, tremors, delirium, diuresis, and other side effects. Large guarana doses might cause headache, anxiety, agitation, ringing in the ears, pain when urinating, stomach cramps, and irregular heartbeats. People who take guarana regularly may experience caffeine withdrawal symptoms if they reduce their usual dose.