Homocysteine is a derivative of the amino acid methionine. It received a great deal of media attention in 1997 following publication of articles in medical journals indicating that a high blood level of homocysteine is a potential risk factor for atherosclerosis, heart disease and stroke. Kilmer McCully, M.D., a pathologist at the Veterans Affairs Medical Center in Providence, Rhode Island, had been claiming for at least two decades that homocysteine is as important a risk factor for heart disease as cholesterol, but few in the medical profession paid serious attention to his claim. Dr. McCully was vindicated with the publication of additional scientific articles in the 1990s, most of which confirmed the dangers of elevated homocysteine levels. Fortunately, homocysteine levels can be easily lowered by taking supplements of B vitamins, particularly folic acid, B6, and B12.
In addition to contributing to cardiovascular conditions, homocysteine may also be detrimental to the brain since it can act as a toxin to brain cells. Dr. L. Parnetti and colleagues, from Perugia University in Italy published in article discussing the role of homocysteine in cognitive decline. They say, "Homocysteine may represent a metabolic link in the cause of atherosclerotic vascular diseases and old-age dementias. Excessive homocysteine is an independent risk factor for coronary artery disease, peripheral vascular disease, and cerebrovascular disease. Homocysteine is a reliable marker of vitamin B12 deficiency, a common condition in the elderly, which is known to induce neurological deficits including cognitive impairment. A high prevalence of folate deficiency has been reported in geriatric patients suffering from depression and dementia. Both these vitamins occupy a key position in the remethylation and synthesis of S-adenosylmethionine (SAMe), a major methyl donor in the central nervous system. Therefore, deficiencies in either of these vitamins leads to a decrease in Sam-e and an increase in homocysteine, which can be critical in the aging brain."
Adequate intakes of folic acid, B6, and B12 will assure that homocysteine levels are kept low. Considering the possibility that there may be individuals, especially the elderly, who are deficient in B6, folic acid, and B12, an inexpensive and simple way to decrease the rate of damage to the brain from homocysteine would be by supplementing with these vitamins.
Homocysteine, heart disease, stroke, and B vitamins
Homocysteine is a derivative of the amino acid methionine. It received a great
deal of media attention in 1997 following publication of articles in medical
journals indicating that a high homocysteine blood level is a potential risk
factor for stroke and heart disease. Kilmer McCully, M.D., a pathologist at the
Veterans Affairs Medical Center in Providence, Rhode Island, had been claiming
for at least two decades that elevated homocysteine is as important a risk
factor for heart disease as cholesterol, but few in the medical profession paid
serious attention to his claim. Dr. McCully appeared to be vindicated with the
publication of additional scientific articles in the 1990s, most of which
confirmed the dangers of elevated homocysteine levels. However, recent studies
have disputed the role of homocysteine in cardiovascular disease.
In two studies published in the New England Journal of Medicine,
lowering of homocysteine levels with B vitamins did not result in any
significant reduction in stroke or heart disease. In fact, in one of the
studies, those who received 0.8 mg folic acid plus 0.4 mg vitamin B-12 and
40 mg vitamin B6 had a higher rate of myocardial infarction.
High blood homocysteine levels can be easily lowered by taking supplements of B
vitamins, particularly folic acid, B6, and B12. Unfortunately, at this time,
having reviewed many studies the positive results and the negative results
regarding homocysteine, no definite statements can be made regarding the
benefits of supplementing with B vitamins in regards to stroke and heart disease
prevention or treatment.
So, what's the bottom line? Should you or should you not supplement
with B vitamins? We say yes. B vitamins have many benefits including
support of mental health and providing more physical energy. But, wedon't think
high doses are required. One, two, or three times the RDA should be fine. We
don't think the B50 or the B100 products, which supply 25 to 50 times the RDA
for certain B vitamins, are necessarily beneficial. It may be a good idea to
just take a multivitamin supplying one, two, or three times the RDA for all the
Bs. Higher amounts of B vitamins, or taking too high a dose of just one or two
of the B vitamins (such as the study I mentioned above where 40 mg of B6 was
given without providing the other B vitamins such as B1 and B2) may be
counterproductive. In a study published in JAMA in the year 2002, homocysteine-lowering
therapy with folic acid, vitamin B12, and vitamin B6 significantly decreased the
incidence of major adverse events after percutaneous coronary intervention. This
study used 10 mg of B6 as opposed to the 40 mg used in the study published by
the NEJM. Could lower dosages of B vitamins actually be healthier?
Homocysteine, memory, and B vitamins
Nutritionists at Tufts University in Boston have also found a connection
between B vitamins, homocysteine, and memory. They investigated the relations between
blood concentrations of homocysteine and vitamins B-12, B-6 and folate, and scores from a
battery of cognitive tests for seventy male subjects, aged 54-81 years. Lower
concentrations of vitamin B-12 and folate and higher concentrations of homocysteine were
associated with poorer memory. Furthermore, people with low levels of vitamin B12 or folic
acid may have a higher risk of developing Alzheimer's disease.khj
Homocystein and psoriasis
Inflammation and hypercoagulable state in adult psoriatic men.
Acta Derm Venereol. 2008. Karabudak O, Ulusoy RE, Erikci AA, Solmazgul
E, Dogan B, Harmanyeri Y. Department of Dermatology, GATA Teaching Hospital,
GATA Teaching Hospital, Istanbul, Turkey.
High homocysteine is a well-known risk factor for cardiovascular disease and
plays a role in atherothrombosis. Psoriasis is a common chronic and recurrent
inflammatory skin disease associated with increased thrombosis. The aim of this
study was to examine serum homocysteine levels and their relationships with
inflammatory and atherothrombotic markers in psoriasis. Twenty patients with
mild or moderate psoriasis and 20 age-matched healthy men were included in this
study. Patients with acquired hyperhomocysteinaemia were excluded from both
groups. The inflammation markers, mean platelet volume, C-reactive protein and
ceruloplasmin levels, were significantly increased in the study group compared
with the control group. In the study group there was decreased antithrombin III
and total homocysteine levels, for haemostatic parameters. Folic acid levels,
cardiovascular risk factors, endothelial inflammation markers and blood
coagulation factors demonstrated significant correlations. Folic acid levels
correlated inversely with homocysteine and positively with fibrinogen levels. In
conclusion, increased homocysteine concentration and inflammation markers may
play a role in the atherothrombotic state in psoriasis.
Medical doctor opinion
Ray Sahelian, M.D. author of
Mind Memory Boosters: A Guide to Natural
Supplements That Enhance Your Mind, Memory, and Mood
says: Homocysteine,
in addition to causing harm to brain cells, can cause hardening of the arteries. Folic
acid and B
Homocysteine questions
Q. I have been reading about homocysteine, and in a TMG (trimethylglycine) web
page I found a statement that does not correspond very well with what I've been
reading in other sites: that the homocysteine is converted to methionine. What I
have read is that homocysteine is a byproduct of the metabolism of methionine
and in turn it will convert into cysteine and this into glutathione.
A. Homocysteine can convert into methionine or cysteine. Methionine
plays a role in the biosynthesis of cysteine, carnitine, and taurine, the
synthesis of phosphatidylcholine, and other phospholipids.
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