-----
>I forwarded the recent soy article on this list to a veg list,
>and got this response:
>
>Mark James writes:
>>I would say a couple immediate things.
>>
>>First, using a drug induced DNA study to attribute claims to a natural
>>occuring version, as found in soybeans is flawed.
I will agree on that
>>
>>Second, if this were true, it would be trivial to find epedemiological
>>studies where subjects in China, japan, and other heavy soy-based dietary
>>regions showed heavier brain damage/aging than countries with little or
>>no soy in the diet. There are no studies, either showing any relation
>>with soy and alzheimers, in fact, countries with heavy soy consumption
>>have lower incidences of alzheimers than, for instance, germany and the
>>US, where soy in the diet is minimal.
We have to take in consideration that asiatic peoples will eat way less soya
that a western vegan is inclined to ,and they have access to a good source
of omega 3 from fish that can compensate the soya on the health of the
brain.
>>
>>So I think putting a warning on this news is a long long stretch.
>>
>>It is interesting news, and may be yet another instnace where synthesized
>>chemicals ahve a very different effect than "organically" occuring
>>versions of the same chemical. For all we know, the brain damaging effect
>>may be caused by left handed versions of the same molecule.
They forget here than tofu and other soya products are so processed than the
molecules produced by the cooking might be far from the" organic version "in
the whole soya , and closer to the synthetized chemicals ..
jean-claude
>Comments?
Here ,is a post related to the 1st article (soy warning), that came in a
raw vegan email list . because they are raw they are more willing to let go
of soya than non raw vegans who made a kind of stapple out of it.
jean-claude
> IS THERE REASON TO BELIEVE TOFU MAY CAUSE BRAIN ATROPHY?
>
> The recent study suggesting a link between tofu and brain
> atrophy [1] calls to attention animal research showing that
> the soy-phytochemical genistein reduces DNA synthesis in the
> brain and inhibits the proliferation of brain cells. [2][3][4]
> That research tends to support the tofu study, for, since cell
> replication requires DNA synthesis, genistein-induced synthesis
> reduction leading to fewer new cells could manifest as atrophy.
>
> The only counter I've seen is that cell-proliferation physiology
> does not apply to adult brain cells, since they don't replicate.
> That claim, however, has been invalidated, for it has been shown
> that neurogenesis--the replication of new brain cells--appears
> to occur in the brain throughout life. As Dr. David Amaral told
> The Washington Post (11/21/99): "A decade ago, we still had the
> notion that you acquired all the neurons you would ever have by
> the sixth month of pregnancy... It turns out that nothing could
> be further from the truth." The Washington Post continued:
>
> "Last month, biologists at Princeton University demonstrated
> that monkey brains constantly produce thousands of new
> neurons which travel to the cerebral cortex, the center
> of higher intellectual functions. Earlier studies had
> documented other examples of neurogensis... The same
> process occurs in humans. ...researchers at the Salk
> Institute for Biological Studies in La Jolla, Calif.,
> found evidence of recent cell division in a part of the
> brain called the hippocampus in every person studied." [5]
>
> Research in animals shows neurogenesis occurs in several areas
> of the adult brain. [6][7][8] Research also shows that reduced
> DNA synthesis decreases the number of new brain cells produced.
> [9] Based on the available data, I would dare to posit that IF
> in fact genistein inhibits DNA synthesis in the adult human
> brain as it has been shown to in developing rat brains [2]
> (and based on human/animal/soy studies, I see no reason to
> believe the rat/soy-to-human/soy extrapolation is unfounded),
> it stands to reason that soy products would reduce neurogensis
> and/or initiate apoptosis (programmed cell death) in the human
> brain, which could manifest itself as brain atrophy. In short,
> there's reason to believe the tofu study [1] may be accurate.
>
> But Asians Are Smarter
>
> A counter argument to the findings in the tofu study [1] is
> that Chinese and Japanese consume more soy products than other
> people, and yet they have very-high IQs, and thus don't appear
> to suffering from a chemically induced diminution of cerebral
> capacity. Sounds plausible on its face, but it should be
> considered that if Asians have higher IQs, due to nature or
> nurture, this does not mean they could not suffer decrements
> of IQ that would go unnoticed if, despite the decrement, they
> still exceed the average IQ of non-Asians. In short, a 500-lb
> man would still be very large even after losing 200 pounds.
>
> Another point to consider is that if Asian families care for
> grandparents more often than in the West, where they may be
> sent to retirement/nursing homes, such family care might tend
> to "conceal" the rate of cognitive decline in Asian countries.
>
> Another factor to consider is if Asians have been consuming
> soy for centuries (while it's relatively new to Westerners),
> then Asians may have inherited immunities to any toxic agents
> in the foods they consume, since those who food x happens to
> harm least tend to survive more, passing on their immunities
> to food-x-toxins to their offspring. In short, Westerners
> may be more vulnerable to toxins in Asian foods, although
> I'm not aware of the races of those in the tofu study. [1]
>
> Of course I hope what I argue above isn't true, and that
> soy products ARE the healthy panacea I've always assumed!
> I've been a vegetarian since I was 13-years old because I
> believe we need to advance beyond the systematic mass murder
> sentient beings simply for pleasurable taste sensations. With
> my refrigerator full of soy stuff, I wish I could be sure now,
> but until the soy picture gets clearer, the evidence is enough
> for me to be inclined to err on the side of caution. However,
> it should be noted that the research indicating an anticancer
> potential for soy is consistent, and research shows that the
> cytotoxic properties of soy products are strongly specific,
> but apparently not entirely exclusive, to cancer cells. If
> I had terminal cancer, I would consider using soy products!
>
> ___________________________________________________________
> [1] Honolulu Star-Bulletin: Too much tofu induces
> ‘brain aging,’ study shows. Helen Altonn 11/19/99
> http://starbulletin.com/1999/11/19/news/story4.html
>
> [2] Exp Neurol 1999 Sep;159(1):164-76.
> Early effects of protein kinase modulators on DNA synthesis
> in rat cerebral cortex.
>
>http://www.ncbi.nlm.nih.gov/htbin-post/Entrez/query?uid=10486185&form=6&db=
m
>&Dopt=b
>
> [3] Brain Research, 1998 Jan 19;781(1-2):159-66.
> Transmural compression-induced proliferation and DNA
> synthesis through activation of a tyrosine kinase
> pathway in rat astrocytoma RCR-1 cells.
>
>http://www.ncbi.nlm.nih.gov/htbin-post/Entrez/query?uid=9507103&form=6&db=m
&
>Dopt=b
>
> [4] About glial cells: NeuroNews: Modulation of
> neuronal activity by glial cells. June 15, 1998
>
>http://neuroscience.about.com/health/neuroscience/library/weekly/aa061598.h
tm
>
> [5] The Washington Post: The Brain's Power to Heal.
> D. Hales and R. Hales, Parade section, 11/21/99, page 10.
>
> [6] Science 1999 Oct 15;286(5439):548-52.
> Neurogenesis in the neocortex of adult primates.
>
>http://www.ncbi.nlm.nih.gov/htbin-post/Entrez/query?uid=10521353&form=6&db=
m
>&Dopt=b
>
> [7] Proc Natl Acad Sci 1999 Sep 28;96(20):11619-24.
> Regeneration of a germinal layer in the adult mammalian brain.
>
>http://www.ncbi.nlm.nih.gov/htbin-post/Entrez/query?uid=10500226&form=6&db=
m
>&Dopt=b
>
> [8] J Comp Neurol 1999 Aug 30;411(3):495-502.
> Neurogenesis in the adult rat dentate gyrus is
> enhanced by vitamin E deficiency.
>
>http://www.ncbi.nlm.nih.gov/htbin-post/Entrez/query?uid=10413782&form=6&db=
m
>&Dopt=b
>
> [9] Brain Res Dev Brain Res 1998 Jun 15;108(1-2):39-45.
> Developmental neurotoxicity of chlorpyrifos: delayed
> targeting of DNA synthesis after repeated administration.
>
>http://www.ncbi.nlm.nih.gov/htbin-post/Entrez/query?uid=9693782&form=6&db=m
&
>Dopt=b
|
