Substance review: Soy isoflavones

Isoflavones are a group of plant derivatives, usually from the soy bean. They are traditionally purported to have a role in reducing heart disease, reducing cancer, assisting in bone health and easing the symptoms of menopause. Soy beans are a native of eastern Asian where they are used extensively in the diet of both humans and livestock and also as a tool for regulating soil in farming. Many popular Asian cooking sauces such as miso are derived from soy-bean, though not all of them contain flavanoids - for example the obvious candidate soy sauce is not usually a source of flavanoids.

Soy beans are considered to be a complete proteins, that is a protein that when consumed also contains the necessary amino acids to maximise the absorption (or bioavailability) of the protein. For this reason it is favoured amongst vegetarians as a good alternative to meat products over other less complete beans.

The mechanism of soy isoflavones come from their chemical structure. The structure of an isoflavone is very similar to the naturally occurring hormone oestrogen and so they are known as a phytoestrogen, in other words an organic substances that can regulate oestrogen in the human body. Soy isoflavones can either compete for oestrogen recptors or increase the amount of oestrogen in the body, depending on the type of phyoestrogen. The two phytoestrogens that are considered to be most beneficial are genistein and daidzen.

Physical effects:
Isoflavones have been seen to cause the feminizing of male animals in a number of trials, due to the effects of there interaction with oestrogen receptors. As a result there is some concern over there effects on male fertility and testosterone levels. Most of these worries however appear to be unfounded, a meta-analysis showed no feminizing effect on healthy men and similarly a clinical trial from the UK found no decrease in virility. Unfortunately that meta-analysis could also be bias as it is paid for in part by the soy industry and conflicts in a minor way with a different trial from one of the same researchers.

Cognitive Effects:
A trial from Australia recorded a significant increase spatial working memory in healthy men. This corresponds with the female ability to out perform in this area, while males generally out perform in visual spatial processing. It should be noted that there appears there is no obvious cognitive improvement in woman, including post-menopausal women for whom soy is purported to be of benefit. Soy has also at times been attributed to memory loss by mainstream media, however this appears to have been taken out of context for the purposes of marketability. The study focus on a number of Indonesian soy consumers, whose tofu is prepared using formaldehyde, compare that to research from the same group which showed tempe (a fermented soy product) improved memory and its not hard to see there was some data clustering.

Conclusion:
Soy Isoflavones should be used at low dosages for men in sports where spatial memory (as opposed to spatial processing) is used. Its not hard to see how increased spatial working memory can help in situations where establishing the form of patterns is useful - a quarterback reading a defensive pattern or a martial artist noticing a pattern in a flaw of their opponent's fighting style. Although it has yet to be properly established, it is probably best to avoid higher dosages of soy, for example as an alternative to whey protein. For women this could cause an imbalance in their oestrogen levels and for men this could significantly reduce the positive effects of testosterone.

Further reading:
http://lpi.oregonstate.edu/infocenter/phytochemicals/soyiso/

Substance Review: Ginkgo Biloba

Ginkgos are deciduous trees that are ancient enough to be considered living fossils and have been found in the fossil record across the world. They are primarily associated with Asia where the only remaining wild Ginkos grow and where the plant got its reputation as a Traditional Chinese Medicine (TCM).

Ginko's earliest mention is in the "Shen-nung pen-ts'ao ching" as an aid for circulation and breathing. Since then various applications of its fruit, leaves and bark have been administered for a range of conditions until eventually Ginkgo found its way to western medicine in the 1950s. In modern alternative medicine it is found as an extract of the fan-like leaves and most often used as a way to enhance learning, help prevent Alzheimer's and improve mood. It has reached quite popular levels with an estimate 2% of the American population using it as a herbal remedy.

Its not documented with any reliability as to how Ginkgo Biloba works, but its modern application focuses on the flavanoids or biologically active material in the leaves known as ginkgolides and bilobalides. It is theorised that these flavanoids are GABA antagonists, which means they stop or slowdown neurotransmission. A light inhibition of nuerotransmission is associated with a reduction of anxiety and a possible maintainance of concentration, while increased inhibition leads to sleepiness.

Physical effects:
If ginkgo creates this calming effect, it may be useful as a nerve settler before a big match or event, but this could come at the cost of feeling lethargic. Of more concern is Ginko's reported side-effects, in particular intercranial bleeding. A comprehensive meta-analysis showed that there was a link between gingko and spontaneous bleeding, though this was most strogly associated with participants who had existing conditions.

Cognitive effects:
For our purposes, Alzheimers is of no true relevance to the improvement of sports specifically so we should focus on ginkgo's purported learning, memory and mood enhancement. That is not to say we will ignore mature atheletes (a category where one of the better gingko studies showed some promise), only that it does not follow that older atheletes will have Alzheimers so it is of no direct benefit to sport.

The amassed research for Gingko is formed of equal parts for and against the herb as a cognitive enhancer. If you stick to the research with best-practice methodologies and ignore the more theoretical studies on rats or small samples of participants, the evidence tends to sway away from any significant cognitive benefit. A popular supplement company's gingko formula was tested to no effect. Similarly a Swedish trial found no impact on memory or learning. That said, a British trial found that Gingko improved quality of memory, while significantly hampering speed of attention. Also in one of the more reliable positive studies ginkgo was found to enhance sustained attention and pattern recognition, however after 6 weeks this enhancement was lost. I would question as to whether it washed out or if it was merely chance and other factors that improved memory attention at the beginning of the trial.


Conclusion:
Ginkgo biloba, may have some very specific cognitive benefits, but it is unlikely. Older athletes looking to stay on top of there game might benefit from cognitive enhancement in remembering and sustained application of say a triathlete's race plan. Younger athlete's might not gain any real benefits from gingko biloba and any they do may well wash out after minimal use. The well conducted trials all point to a distinct lack of evidence for cognitive enhancement, depsite what is touted by TCM and when you consider its genesis in this field was as a blood circulator it hardly seems surprising. Under no circumstance would I recommend gingko as a supplement for martial artists or participants in contact sports. There is a significant correlation between ginkgo and exacerbating bleeding, in particular intercranial bleeding. The risk isnt worth the reward.

What to watch out for:
Sometimes its put in with other herbal remedies and while it may not necessarily be of a significant dosage its good to keep an eye out for:

• Ginkgo biloba is sometime mislabelled as gingko
• Yin Xing
• Maidenhair derivatives

Further reading:
http://www.slate.com/id/2165042/pagenum/all/