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Definition: "An ergogenic aid is any substance or phenomenon that enhances performance "
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27.11.2010 |
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So vitamin E does extend life expectancy...
Since big metastudies claimed that vitamin E supplements increase the chance of dying by a couple of percent, vitamin E has lost its name as a life extender. [JAMA. 2007;297:842-857.] Not so, say biologists at the University of Aberdeen. Vitamin E does extend life expectancy – you just have to take it for a longer period of time.
In 2008 the researchers published the results of a study in which they gave C57BL/6 mice 25 times more alpha-tocopherol [the vitamin E analogue in most supplements] than the recommended amount from the age of fourth months. [Rejuvenation Res. 2008 Feb;11(1):83-96.] The mice were given 550 mg alpha-tocopherol per kg feed.
The mice in the group that had been given extra vitamin E lived 15 percent longer than the mice in the control group. The latter got 22 mg alpha-tocopherol per kg feed.
During the first 18 months the supplement activated detoxifying enzymes in the liver, the Brits discovered. Apparently the mice's body regarded the vitamin as an alien ['xenobiotic'] substance and started producing more enzymes to remove the vitamin from the body.
After 18 months this effect disappeared and the supplement started to boost the activity of the p21 gene, a molecular switch that activates a series of genes that protect against cancer.
The researchers did a literature study from which they concluded that vitamin E extends the life of mice and rats under two conditions: the doses are not too high, and supplementation is long term.
"We suggest that when vitamin E is administered over short periods, enhancement of the xenobiotic metabolism response may nullify any beneficial effects", the researchers conclude. "Indeed, short-term administration of vitamin E in humans may actually have a negative impact on all cause mortality when administered at high doses."
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