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Angeles Garcia and Katherine Zanibbi
Homocysteine and cognitive function in elderly people
CMAJ 2004; 171: 897-904 [Abstract] [Full text] [PDF]
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[Read eLetter] This could be due to loss of DHEA of old age...
James M. Howard   (15 November 2004)

This could be due to loss of DHEA of old age... 15 November 2004
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James M. Howard
independent biologist

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Re: This could be due to loss of DHEA of old age...

jmhoward{at}anthropogeny.com James M. Howard

It is my hypothesis that dehydroepiandrosterone (DHEA) was selected by evolution and produced mammals and their large brains (Hormones in Mammalian Evolution, Rivista di Biologia / Biology Forum 2001; 94: 177- 84). I think DHEA was selected by evolution because it may optimize replication and transcription of DNA. Therefore, DHEA is important to all tissues, especially the brain.

While tentative, Bednarek-Tupilowska and Tupilowski reported that "Individual data showed that dehydroepiandrosterone probably lowers Hcy [homocysteine] level." (Postepy Hig Med Dosw (online) 2004; 58: 381-9). I suggest that low DHEA causes the increase in homocysteine. Low DHEA has been connected with Alzheimer's disease and dementia. DHEA naturally begins to decline around age twenty, reaching very low levels in old age.

I suggest it is low DHEA, not increased homocysteine, that causes dementia of old age.

Conflict of Interest:

None declared