Homocysteine & Brain Aging
Ian Goddard
and homocysteine, and the blocking of such by folic
acid, and vitamins B 6 and 12 keeps coming out...
(thanks to the person who posted this link to crsociety)
http://my.webmd.com/content/article/1626.51332
Vitamins Fight Alzheimer's
By Liza Jane Maltin Reviewed
WebMD Medical News By Michael Smith, MD
May 28, 2002 -- There's new evidence that a substance found in
blood can cause the type of brain and blood vessel deterioration
that leads to dementia. But those same studies also show that
taking certain vitamins can lower levels of this substance --
homocysteine -- and ward off the damage, possibly preventing
Alzheimer's disease.
Both studies and an accompanying editorial appear in the May 28
issue of Neurology.
Homocysteine is an amino acid -- the building blocks of protein
-- that circulates in our bloodstream. Alzheimer's patients tend
to have elevated homocysteine levels, as do 5%-7% of the general
population. High homocysteine levels have been linked to heart
disease and stroke.
In the first study, Joshua W. Miller, PhD, from the University
of California, Davis, School of Medicine in Sacramento, and
colleagues found that elevated levels of homocysteine were linked
to blood vessel damage, and that having low levels of vitamin
B-6 in the blood was common among Alzheimer's patients, suggesting
a relationship between B-6, homocysteine, and Alzheimer's. But
what that relationship may be is unknown.
The findings need to be confirmed, and "it remains to be determined
if elevated homocysteine or low vitamin B-6 directly influence
Alzheimer's disease progression," Miller says in a news release.
"But it is interesting. Vitamin B-6 has been shown to play a role
in brain function and memory, so it's possible that taking B-6
supplements could help Alzheimer's patients."
In the second study, Perminder Sachdev, MD, PhD, of Prince of
Wales Hospital in Randwick, Australia, and colleagues looked at
the brains and homocysteine levels of 36 healthy seniors. They
found that those with high homocysteine levels were twice as
likely as those with normal levels to show loss of brain cells.
Whether the excess homocysteine is actually causing the brain
deterioration remains to be seen.
"This is exciting information, because homocysteine levels can
be reduced by taking the vitamins B6, B12, and folic acid," says
editorial author James Toole, MD, in a news release. He is a
neurologist at Wake Forest University School of Medicine, in
Winston-Salem, N.C.
Good sources of folic acid include citrus fruits and juices,
tomatoes, vegetables, and grain products such as bread, cereal,
and pasta. Vitamin B-6 is found in meat, poultry, fish, fruits,
vegetables, and grain products, and vitamin B-12 is plentiful in
meat, poultry, fish, and dairy products. You can get a sufficient
amount of all three nutrients if you eat a varied, well-balanced
diet.
"To lengthen thy life, lessen thy meals." Ben Franklin
http://www.ultrahiq.net/Ubiquity/Winter02/CR.html
Fat to Thin: http://IanGoddard.net/me-cr.htm
Ian Goddard
http://my.webmd.com/content/article/1626.51332
(Follow these links for additional information)
http://www.neurology.org/cgi/content/abstract/58/10/1539
Neurology 2002;58:1539-1541 - American Academy of Neurology
Relationship between plasma homocysteine levels and
brain atrophy in healthy elderly individuals
[authors and affiliations cut for brevity, see URL above]
The authors examined the association of total plasma homocysteine
(Hcy) levels with measures of atrophy and white matter disease on
MRI scans in 36 healthy elderly individuals. Hcy had a significant
positive relationship with lateral ventricle-brain ratios in the
anterior (r = 0.49) and middle (r = 0.43) ventricular regions as
measures of central atrophy, but not with cortical atrophy or
white matter hyperintensities. In a logistic regression analysis,
elevated Hcy was a significant determinant of increased anterior
ventricle-brain ratio (0.34) after controlling for age, folate,
B12, creatinine, and white matter disease (OR = 2.3; CI, 1.03-5.09).
********************************************************************
http://www.neurology.org/cgi/content/abstract/58/10/1471
Neurology 2002;58:1471-1475 - American Academy of Neurology
Homocysteine, vitamin B6, and vascular disease in AD patients
[authors and affiliations cut for brevity, see URL above]
Background: Cerebrovascular disease is a cause of dementia
and is associated with elevated plasma levels of homocysteine.
Patients with AD tend to have unexplained elevations of
homocysteine concentrations vs healthy control subjects.
Vitamin B6 status, a potential determinant of plasma
homocysteine, has not been characterized in patients with AD.
Objective: To investigate plasma homocysteine, vitamin B6 status,
and the occurrence of vascular disease in patients with AD.
Methods: Forty-three patients with AD and 37 control subjects
without AD were studied for homocysteine, B vitamin status
(folate, vitamin B12, pyridoxal-5'-phosphate [PLP]), kidney
function (creatinine), and thyroid function (thyroid-stimulating
hormone, thyroxin). In addition, the presence of vascular disease
was assessed by reviewing both medical histories and brain imaging
data provided by CT and MRI.
Results: The OR for elevated plasma homocysteine (>12 ľmol/L)
was only 2.2 (not significant) for subjects with AD. In contrast,
the OR was 10.0 (p = 0.03) for subjects with vascular disease
(n = 26). The OR for low plasma PLP (<25 nmol/L) was 12.3
(p = 0.01) for patients with AD. No significant relationship was
observed between vascular disease and PLP level or between plasma
homocysteine and PLP concentrations.
Conclusions: Elevated plasma homocysteine in patients with AD
appears related to vascular disease and not AD pathology. In
addition, low vitamin B6 status is prevalent in patients with AD.
It remains to be determined if elevated plasma homocysteine or
low vitamin B6 status directly influences AD pathogenesis or
progression.
****************************************************************
Tom Matthews
> Evidence indicating a connection between brain aging
> and homocysteine, and the blocking of such by folic
> acid, and vitamins B 6 and 12 keeps coming out...
My own view of the evidence is that reducing homocysteine in all possible ways
is far more important for health and longevity than is reducing cholesterol.
This is especially true for low levels. Ie. minimal cholesterol is definitely
needed, but homocysteine has no value that I am aware of (though I'm sure
someone will prove me wrong if they hunt hard enough :)
BTW, for many people, it seems that vitamins B6, B12 and folic acid will only
reduce it so far. In order to do more they need to invoke another conversion
pathway by supplementing trimethylglycine (TMG, also called glycine betaine)
--Tom Matthews
MoreLife for the rational - http://morelife.org
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