Guarana

Synonym(s): caffeine, caffeine

Nutrient group: plant extracts & active ingredients

Sources and physiological effects

Dietary sources
Guarana belongs to the Sapindaceae family and is native to the Amazon Basin. The seeds are used to produce both coffee-like drinks and lemonades, which are particularly popular in Brazil. Guarana is also used in chocolate, teas, chewing gum and energy drinks. Due to the high proportion of tannins, the effect of caffeine is delayed and subsequently prolonged.
Physiological effects
Fatty acid metabolism	Stimulation of fat metabolism by increasing thermogenesis
Nervous system	Activation of the sympathetic nervous system Increase in cognitive performance

Detailed information

Guarana with naturally bound caffeine

The guarana plant is classified as a caffeine drug and used preventively and therapeutically as a psychostimulant or psychotonic. The main site of attack of caffeine is the central nervous system, where it has a direct and widespread stimulating effect and improves mood parameters (1). Guarana thus has a positive effect on drive and mood. Studies have shown that this is not solely due to caffeine activity, as low doses of guarana (up to 100 mg) have a greater effect on cognitive parameters than higher doses (2). Similar psychoactive effects have been demonstrated for ginseng in humans (3).

Metabolic support

Caffeine is connect to increased thermogenesis (4). Caffeine from guarana influences the fatty acid metabolism and seems to have general protective effects against hypertension, obesity and metabolic disorders (5) (6). The inhibition of catechol-O-methyltransferase and phosphodiesterase as well as the excitation of the sympathetic nervous system are proposed as mechanisms of action (7).

Caffeine to increase performance and attention

The caffeine contained in guarana is used therapeutically to increase cognitive performance such as reactivity and memory, reduce fatigue and improve performance. Several studies have shown that caffeinated guarana extract can increase reaction time and positively influence learning processes (8).

Indications

Effect	Indication	Dosage
Physiological effects at a low intake	To improve performance and concentration at fatigue	300 – 400 mg/d
	To improve mood parameters and cognitive abilities	100 – 200 mg/d
	To reduce risk factors from abdominal fat distribution	300 – 400 mg/d

Administration

General mode of administration
When	Guarana should be taken between meals. Notes: It is recommended that sensitive people take it with meals.
Side effects
Sensitive individuals or people taking high doses may experience caffeine-dependent, reversible symptoms such as nervousness, sleep disorders and headaches.
Contraindications
Caffeine should be avoided during pregnancy, lactation and in people with high blood pressure.

Interactions

Drug interactions
None	No relevant interactions are known to date.
Nutrient interactions
Trace elements	Caffeine minimally increases calcium excretion.
Amino acids	Caffeine can reduce the ergogenic effects of creatine.

References

1) McKay, D. Nutrients and botanicals for erectile dysfunction. 2004. examining the evidence. Altern Med Rev 9(1):4-16.
2) Haskell, C. F. et al. 2007. A double-blind, placebo-controlled, multi-dose evaluation of the
actual behavioural effects of guarana in humans. J Psychopharmacol. 21(1):65-70.
3) Kennedy, D.O. et al. 2004. Improved cognitive performance in human volunteers Following administration of guarana (Paullinia cupana) extract. Comparison and interaction with Panax ginseng. Pharmacol Biochem Behav. 79(3):401-11.
4) Hursel, R., Westerterp-Plantenga, M. S. 2010. Thermogenic ingredients and body weight regulation. Int J Obes (Lond). 34(4):659-69.
5) Lima, W. P. et al. 2005. Lipid metabolism in trained rats: Effect of guarana (Paullinia cupana Mart.) supplementation. Clin Nutr. 24(6):1019-28.
6) da Costa Krewer C. et al. 2011 Habitual Intake of Guaraná and Metabolic Morbidities: An Epidemiological Study of an Elderly Amazonian Population. Phytother Res.
7) Diepgens, K. et al. 2007. Obesity and thermogenesis related to the consumption of caffeine, ephedrine, capsaicin, and green tea. Am J Physiol Regul Integr Comp Physiol. 292(1):R77-85.

References Interactions
Stargrove, M. B. et al. Herb, Nutrient and Drug Interactions: Clinical Implications and Therapeutic Strategies, 1. Auflage. St. Louis, Missouri: Elsevier Health Sciences, 2008.
Gröber, U. Mikronährstoffe: Metabolic Tuning –Prävention –Therapie, 3. Auflage. Stuttgart: WVG Wissenschaftliche Verlagsgesellschaft Stuttgart, 2011.
Gröber, U. Arzneimittel und Mikronährstoffe: Medikationsorientierte Supplementierung, 3. aktualisierte und erweiterte Auflage. Stuttgart: WVG Wissenschaftliche Verlagsgesellschaft Stuttgart, 2014.