Gurana
Common Name
Standardized: guarana
Botanical Name
Paullinia cupana Kunth
Plant Family: Sapindaceae
Overview
Now certified organic! A native evergreen, guarana is a sprawling, shrub like vine native to the Amazon region. The guarana tree produces red berries that have been used like coffee in its native Brazil for centuries. When ripe, the berries split open at the end and look similar to a human eyeball. A legend of the Satare-Maure Indians of Brazil tells that a beautiful woman named Onhiamuacabe gave birth to a child whose father was said to be a "mysterious being." The child was eventually put to death for eating some type of forbidden nuts. At his burial site a guarana bush began to grow from his eye. Native Indians still consider the effects of guarana to be supernatural in nature. Our guarana seeds are dried and roasted. They are brewed to make a drink that is at first bitter and slightly astringent, later becoming sweet. Older texts contain reference to a substance called guaranine, said to be chemically identical to caffeine. More recently, many chemists argue that the substance IS caffeine, making guarana the highest source of caffeine available in nature. Guarana seeds contain 2.5 times the amount of caffeine that coffee does.
Parts Used
Seed
Typical Preparations
Brewed as a tea, in food and snack items, added to coffee, as a capsule, and in extract form.
Summary
Guarana was cultivated by the indigenous peoples as far back as Pre-Columbian times, and was first commercialized for use in 1958. Guarana shows many promising health benefits, though research is ongoing.
Health Benefits
Many people who consume beverages containing guarana are devotees, and they may not concern themselves with research that proves how the drinks make them feel. Nevertheless, it's worth digging into what is proven (and not).
Decreased Fatigue
A 2011 study of breast cancer patients undergoing systemic chemotherapy and a 2018 study of patients with chronic kidney disease found that patients taking guarana experienced significantly reduced fatigue compared with those taking a placebo.
The study of breast cancer patients used a 50 milligram (mg) dose twice daily, and the study in patients with chronic kidney disease examined the effects of doses as high as 200 mg and 400 mg, indicating anti-fatigue effects at low and high doses.
Additionally, antioxidant effects of guarana extracts have been observed in pre-clinical trials, according to a review published in 2018. According to one study, oxidative stress shows promise as a potential biomarker for chronic fatigue syndrome.
Improved Cognition
A randomized, double-blind crossover study assessed cognitive performance with a go/no-go task in 56 participants after they had ingested either a multi-vitamin/mineral preparation supplemented with 300 mg guarana, a caffeine supplement, or a placebo supplement. It was found that responses were faster on the go/no-go task without a change in accuracy between 30 and 90 minutes after ingesting the guarana.
A significant decrease in heart rate variability was observed during the first hour after taking the caffeine, yet remained stable after taking guarana, suggesting guarana may be able to improve decision-making performance without destabilizing autonomic nervous system regulation during the first hour as much as caffeine does.
Another double-blind, placebo-controlled study of guarana use throughout the day found that guarana improved secondary memory performance, mood, and alertness at low (37.5 mg, 75 mg) and higher (150 mg, 300 mg) doses, with the lower doses being more effective.
While this data is promising for acute uses, a study examining the use of guarana, caffeine, and placebo on the cognition of 45 older individuals found no significant lasting effects of guarana on cognition long-term.
Weight Loss
Guarana supplement manufacturers sometimes claim that guarana is helpful for promoting weight loss, but there is not a lot of clinical research to support this.
It is possible that proponents are relying on data from a 2001 study—a randomized, double-blind, placebo-controlled trial that examined the effects of 240 mg/day guarana (as a caffeine source) combined with 72 mg/day Ma Huang, containing ephedrine alkaloids. Over the eight weeks of treatment, this combination led to a significantly greater loss of weight and fat as well as larger reductions in hip circumference and serum triglyceride levels, as compared with placebo.
It's important to note that these effects cannot be attributed to the guarana alone, and eight of the study participants quit the study early as a result of unwanted side effects—insomnia and headache being among the most frequently reported.
An animal study from 2005 examined the effect of 14 days of guarana supplementation on fat metabolism in sedentary and trained rats and found a fat-burning effect attributable to the caffeine content, but more research is needed.
Possible Side Effects
Guarana contains a large amount of caffeine, and the precise amount may not be properly documented on the label. Side effects can include those common to many stimulants:
- Stomach irritation
- Increased heart rate
- Increased blood pressure
- Nervousness/agitation
A 2018 study of patients with chronic kidney disease found that incidents of headaches, insomnia, gastric discomfort, nausea and vomiting were highest in the group taking 400 mg of guarana per day.
Precautions
Specific: Guarana seed contains caffeine
and may cause nervousness, irritability, sleeplessness, and,
occasionally, rapid heartbeat. Not recommended for use by children
under 18 years of age.
General: We recommend that you consult with a qualified
healthcare practitioner before using herbal products, particularly if
you are pregnant, nursing, or on any medications.
