What is Guarana?
Guarana is a climbing plant that belongs to the maple family, Sapindaceae. It can be found in the Amazon basin and is often found in Brazil. Extract of Guarana seed has a number of uses, including weight loss and energy supplements. Aside from taking the guarana seed itself, there are no natural food sources of guarana although thanks to its effects, it has become a common additive to some foods and drinks.
What is guarana used for?
Guarana is often found in weight-loss supplements and that’s because Guarana is thought to be an effective fat-burner. Research has shown that guarana taken with other supplements really does help with weight loss.
Researchers aren’t completely sure if it is the guarana specifically that is responsible for the weight-loss effect or if it is the caffeine that is dong the job, since caffeine is also linked to weight loss. As a weight loss supplement, caffeine has been found to work best when combined with the polyphenol compounds in green tea, and it is thought that combining guarana with polyphenols may have a similar effect.
Guarana is also used in many energy drinks and supplements. Some studies suggest that the active ingredient of guarana was a chemical that was specific to the plant — guaranine. Others suggest that it is just caffeine in guarana that has any effect. Guarana has one of the highest concentrations of caffeine in any plant. It is thought to contain up to 3.6% to 5.8% caffeine by weight – contrast this with coffee which has only around 2%.
Of course, we know that coffee and other drinks with caffeine in them are good for keeping us awake! Scientifically, caffeine has been shown to improve mental performance and alertness in sleep-deprived people, and it is logical therefore that guarana has the same effect.
How could guarana help people lose weight?
There are a number of ways guarana might work as a fat burner
Firstly, because of its high caffeine content, it might stimulates the nervous system, which sends direct signals to the fat cells to tell them to break down fat (want to read more about this? try this and this – no need to buy the articles, just read the abstracts for a summary)
Caffeine also increases our blood levels of the hormone Epinephrine, better known as Adrenaline. This travels through the blood, to the fat tissues and send signals to break down fats and release them into the blood. This is how caffeine is thought to help to mobilise fat from the fat tissues, making it available for use as free fatty acids in the blood.
Another way guarana is thought to help people burn fat is by making them feel more full, quickly. This means you eat less and of course lose weight as a consequence.
There have been a number of studies that looked into the effectiveness of guarana, both as a fat burner and for improving mental performance. These are the most cited:
- Journal of Psychopharmacol 2007 – A double-blind, placebo-controlled, multi-dose evaluation of the acute behavioural effects of guaraná in humans. The study concluded that there were cognitive improvements following 75 mg guaraná which could not be attributed to caffeine alone.
- Phytotherapy Research 2011 – Habitual Intake of Guaraná and Metabolic Morbidities: An Epidemiological Study of an Elderly Amazonian Population. Fewer people in the group taking Guarana had hypertension, obesity and metabolic syndrome. The males in the group had a smaller waist circumference, on average than those not taking it. The females had lower cholesterol (total and LDL-c) levels and there were lower levels of advanced oxidative protein product (AOPP). The study suggests that Guarana has a protective effect against metabolic disorders in elderly subjects (since it was elderly subjects that the study examined).
- Journal of Human Nutrition and Dietetics 2001 – Weight loss and delayed gastric emptying following a South American herbal preparation in overweight patients. The study showed an average 5.1 kg (11.2 lb) weight loss in a group taking a mixture of yerba mate, guarana, and damiana, compared to an average one-pound loss in a placebo group after 45 days.
Are there risks with taking guarana?
As you might expect, since guarana is high in caffiene, the side effects reported from taking guarana are the same as the side effects you get from having too much caffeine. These include a rapid heartbeat, anxiety, sleep problems, restlessness, anxiety, and an upset stomach. We know that long-term use of caffeine may result in tolerance and psychological dependence. There are also risks of taking too much caffeine which include high blood pressure, increased heart rate and breast disease.
It is always advisable to talk to your doctor or healthcare advisor before starting any new supplement, but this is particularly the case for guarana if you have existing problems with anxiety, high blood pressure, kidney problems, glaucoma, osteoporosis, bleeding disorders, MVP, heart problems, diabetes or liver disease. Guarana may also interact with medicines like blood thinners, some antidepressants, lithium and sedatives. You should certainly avoid using guarana with other stimulants, whether medications, supplements, or street drugs, and you need to be careful of excessive caffeine intake resulting from taking guarana and drinking caffeinated drinks like coffee and sodas.
Guarana is not recommended for children and should be avoided by women who are pregnant or breastfeeding.