Nutrition Beyond the Trends: The 400-pound Guarana in the Room
Natural caffeine is abundant in our modern, high-energy society. The sun never sets on the Starbuck’s empire. And talk about teas, once we discovered antioxidants and EGCG, variety in the tea market went through the roof.
By Mark Anthony, Ph.D. | 09/06/2006
No longer do we choose from black tea to sip and black tea to ice. We’ve got green tea, white tea and tea in everything from carbonated beverages to ice cream. Antioxidants have also increased the popularity of chocolate — another popular source of natural caffeine — moving it from once-decadent dessert indulgence to guiltlessly healthy snack.
We must be in need even of more energy, because caffeine-laden “energy” drinks fill the coolers from grocery stores to gas stations. Many of these energy drinks are spiked with synthetic caffeine. Others use caffeine from decaffeinated coffee (which still is natural). But there’s another source of natural caffeine in the energy drinks hitting the market with force. It’s a special seed called guarana.
Guarana comes from the Paullinia cupana plant, a shrub or small tree native to Brazil. It’s a member of the family of shrubs called soapberry plants that thrive in the tropics. The name guarana is derived from the Tupi-Guarana word wara’ná. The indigenous Tupi and Guarana tribes believe it to be a magical plant that can cure g.i. complaints and aid in the recovery of strength and vitality.
Some of that “vitality” comes straight from caffeine: Gaurana seeds are 2.5 to 7 percent caffeine, compared to 1 to 2 percent in a coffee bean. The natural caffeine in guarana, often called guaranine, stimulates the central nervous system, and hence brings with it both perceived pluses and minuses of the more familiar drinks. Caffeine can quicken perceptions, aid endurance and reduce appetite. It can also increase blood pressure and heart rate, which can make you feel jittery, prevent sleep, and increase visits to the bathroom.
There is concern that gaurana, in combination with drugs or other caffeine-containing substances that target the sympathetic nervous system, may have additive effects on blood pressure. Conversely, there is interest in some of the potential positive aspects of this complex plant.
Guarana happens to be a rich source of tannins (up to 16 percent in the dry berries). Some tannins have earned a reputation as potential defensive components against DNA damage. Various tannins, such epigallocatechin-3-gallate from green tea, theafulvins and theaflavins from black tea and procyanidins from grape seeds are believed to be protective against certain forms of cancer.
An animal study recently published in the Journal of Food and Chemical Toxicology suggested guarana is protective against DNA damage induced in the liver. In this study, guarana appeared to protect against a specific type of DNA damage to liver, as long as the dosage was relatively low. Previous studies using much higher doses suggested guarana could be toxic and actually act as a potential mutagen, increasing risk of aberrant cells.
However, a 1998 animal study from Ireland, published in the Journal of Ethnopharmacolocy, indicated that even at high doses, tissues remain unaltered. Furthermore, guarana, when supplied at low concentrations in water, inhibited lipid peroxidation. In other words, the science behind guarana indicates that, as with most compounds, a little can go a long way.
Another 1998 animal study indicated guarana may help protect against ulcers – at least for those who imbibe in alcoholic beverages. The research, reported in the Journal of Ethnopharmacology and conducted in Brazil (where guarana is native) revealed that guarana reduced lipid peroxidation, even in small doses. Lipid peroxidation has the potential to damage cell membranes. This may help to explain why guarana protected the animal models in the study from gastric ulceration induced by the administration of ethanol (and the drug indomethacin).
Other attributes of guarana have been highly touted. For example: Guarana is presented as a weight-loss aid. There are studies that suggest this, but none prove guarana to act in a manner any different from caffeine or other stimulants.
The big selling point of many guarana-containing products these days hinges on suggestions guarana may aid memory and slow down memory loss.
In 2004, a study published in the Journal Pharmacology, Biochemistry and Behavior, reported improved cognitive performance in human volunteers given guarana extract.
The study evaluated speed of attention, speed of memory, accuracy of attention, secondary memory and working memory. Other measures included logical reasoning and sentence verification. The results showed a significant positive effect on speed of attention, reaction times, and secondary memory (delayed word and picture recognition, and immediate and delayed word recall). The low dose of guarana in these experiments suggested the cognitive effects were due to more than the caffeine.
At present the food applications for guarana have been restricted to mostly soft drinks and energy drinks. It is a natural food with a long tradition in Brazil. But there are many questions about its use, mostly related to the amount of natural caffeine. Much study is needed to learn whether the other potential benefits come out from under the caffeine shadow. It’s not a miracle ingredient, or a quick weight-loss solution. Guarana is, however, a reasonable and marketable alternative to other ways of spiking energy drinks.