Ginkgo Biloba may increase the growth impulse of resistance training, a Slovakian study suggests. According to the study, published six years ago in the Journal of Physiology and Pharmacology, a single Ginkgo capsule reduces the release of cortisol after a stressful event.
The Slovaks had seventy test persons learn words off by heart, and then asked them to write these words down. At the same time the test persons had to squeeze hand grips. Combining the two tests produced psychological and physical stress. Stress usually induces an increase in the production of the stress hormone cortisol, but this did not happen in the men that took 120 mg of Ginkgo 30 minutes before the test (see the figure below).
EGb 761 = Ginkgo extract.
Ginkgo slows down the production of cortisol in two ways. The leaves contain Ginkgolide B, a heavily oxidised terpene, that slows down the production of cortisol from cholesterol in the cells of the adrenal glands. [Cell Mol Biol (Noisy-le-grand). 2002 Sep;48(6):633-9.]
The second way in which Ginkgo decreases cortisol levels only becomes evident when Ginkgo is used over a long period of time. According to animal studies, the same Ginkgolide B slows down the release of corticotropin releasing hormone (CRH) by the hypothalamus. [Life Sci. 1998;62(25):2329-40.] CRH makes the adrenal gland produce cortisol.
Decreasing the cortisol level is interesting for strength trainers as well as those seeking longevity. Cortisol is a catabolic hormone: the fewer catabolic hormones circulate in your body after training, the more muscle mass and strength you build up.
For longevity seekers it also is worthwhile decreasing the level of cortisol, as cortisol is not only a stress hormone but also an aging hormone. Elderly people produce more cortisol than young people, and an elevated cortisol level prevents brain cells from making new connections. Survival chances at a higher age improve if brain cells make more new connections.
Reduction of rise in blood pressure and cortisol release during stress by Ginkgo biloba extract (EGb 761) in healthy volunteers.
Jezova D, Duncko R, Lassanova M, Kriska M, Moncek F.
Laboratory of Pharmacological Neuroendocrinology, Slovak Academy of Sciences, Bratislava. firstname.lastname@example.org
The standardized extract of Ginkgo biloba (EGb 761) was found not only to improve memory and aging associated cognitive deficits but also to exert beneficial effects on mood. An antistress action of the extract has been suggested but not directly proven. The present study was aimed to evaluate the effects of EGb 761 on salivary cortisol and blood pressure responses during stress in healthy young volunteers (n = 70) in a double blind placebo controlled design. A stress model involving a combination of static exercise (handgrip) and mental stimuli was used. Single treatment with EGb 761 (120 mg) reduced stress-induced rise in blood pressure without affecting the heart rate. Salivary cortisol responses showed differences with respect to the gender and the time of day of the stress exposure, with the activation only in male subjects in the afternoon. This activation was absent if they were treated with EGb 761. The performance in a short memory test with higher scores achieved by women remained unaffected by EGb 761 treatment. Thus, this study provides evidence that EGb 761 has an inhibitory action on blood pressure and it may influence cortisol release in response to some stress stimuli.
PMID: 12369732 [PubMed - indexed for MEDLINE]