[Paleopsych] BH: Green Tea a Performance-enhancing Drug

[Premise Checker]

Green Tea a Performance-enhancing Drug
http://www.betterhumans.com/Print/index.aspx?ArticleID=2005-01-27-4

Equivalent of four cups a day improves swimming endurance up to 24% in mice
while stimulating the use of fat as energy

    Betterhumans Staff
    1/27/2005 5:00 PM

    Cup of Tea

    Credit: Andrzej Burak

    Sports drink: Green tea appears to boost exercise performance by
    spurring the use of fat during endurance activities

    Green tea may soon show up in locker rooms and doping tests after
    being found to boost exercise endurance in mice up to 24% while
    spurring the use of fat as energy.

    While the finding is based on green tea extract (GTE) and is difficult
    to extrapolate to human athletes, Japanese researcher Takatoshi Murase
    estimates that to match the effects athletes weighing 75 kilograms
    (165 pounds) would need to drink about four cups of [8]green tea a
    day--and over several weeks.

    "One of our important findings," says Murase, "was that a single
    high-dose of GTE or its active ingredients didn't affect performance.
    So it's the long-term ingestion of GTE that is beneficial."

    Exercise boost

    The study was conducted by Murase and colleagues at the Biological
    Sciences Laboratories of [9]Kao Corp. in Tochigi, Japan--a company
    that makes green tea beverages and has been investigating the tea's
    anti-obesity effects.

    The researchers say their findings show that green tea extract can
    boost exercise capacity and support the hypothesis that stimulating
    the use of fatty acids can improve endurance.

    While acknowledging that the impact of dietary interventions on
    performance is controversial, the researchers note that compounds in
    green tea called [10]catechins have already been found to have various
    physiological effects.

    These include counteracting obesity from a high-fat diet, for which
    the researchers recently demonstrated evidence. This finding suggested
    that catechins stimulate fat oxidation.

    It's thought that this might improve exercise performance by allowing
    the body to get energy from fat rather than carbohydrates during
    endurance activities.

    Supplemental benefits

    To test the theory that catechins boost endurance capacity by
    stimulating fat burning, the researchers used mice swimming in an
    adjustable-current water pool. Some of the mice received no green tea
    compounds, others received green tea extract and still others received
    only a catechin in green tea known as EGCG.

    Mice on no supplements could swim about 33 minutes before they were
    exhausted. Mice on green tea extract consistently performed better
    after the first week and by week nine those taking 0.5% green tea
    extract by weight could swim 40 minutes compared to 33 for the
    controls. A similar effect was observed in mice on EGCG, suggesting
    that it was at least partly responsible for the benefits.

    To support their theory about fat burning, the researchers found that
    fatty acids in blood increased slightly but significantly in mice on
    the supplements. They say that their findings suggest that green tea
    extract enhanced the ability of muscle to use fatty acids as an energy
    source.

    To avoid potential complicating factors in other studies, the
    researchers controlled for possible influences of caffeine--a known
    performance enhancer--and changes that might have affected the
    animals' buoyancy.

    The next steps are to determine the molecular mechanism by which green
    tea stimulates fat burning and whether the antioxidant properties of
    catechins mediate their effects on endurance capacity.

    The research is reported in the [11]American Journal of
    Physiology--Regulatory, Integrative and Comparative Physiology.
    Tools
    [12]Related content

References

    8. http://www.wikipedia.org/wiki/Green_tea
    9. http://www.kao.co.jp/e/
   10. http://www.wikipedia.org/wiki/Catechin
   11. http://ajpregu.physiology.org/
   12. http://www.betterhumans.com/Print/index.aspx?ArticleID=2005-01-27-4#RelatedContentLinks