Vitamins & Exercise
Heart Attack Prevention Series
Medical
Authors: Daniel Lee Kulick, MD, FACC, FSCAI and
Dennis Lee, MD
Medical Editor: William C. Shiel Jr., MD, FACP, FACR
Additional Heart Attack Prevention Information
Folic acid, B vitamins, and homocysteine
Homocysteine is metabolized (chemically transformed) into methionine and
cysteine with the help of the B vitamins; folic acid, B12, and B6 (pyridoxine).
Therefore, insufficient amounts of these B vitamins in the body can
theoretically hamper the metabolic breakdown of homocysteine, and hence increase
its blood levels. High levels of homocysteine in the blood
(hyperhomocysteinemia) can damage the inner surface of blood vessels, promote
blood clotting, and accelerate atherosclerosis.
The current state of knowledge regarding folic acid, homocysteine, and
heart
attacks is as follows:
- The level of blood folate is an important determinant
of the blood homocysteine level. Low blood folate levels are associated with
high blood levels of homocysteine.
- Low blood folate is common among individuals who do
not take multivitamins, but unusual among those who do.
- The consumption of folic acid supplements or folic
acid fortified cereals can increase blood folate levels and decrease blood
homocysteine levels.
- In a
large population study involving women, those who had the highest consumption of
folic acid (usually in the form of multivitamins) had fewer heart attacks than
those who consumed the least amount of folic acid.
Even though current
scientific evidence suggests that taking folic acid and vitamin B supplements to
lower homocysteine levels should help prevent atherosclerosis and heart attacks,
conclusive proof is still lacking because:
- There are no conclusive controlled studies (discussed
at the beginning of this article) demonstrating that increasing folic acid
intake actually prevents atherosclerosis and heart attacks.
- There is no clinical study demonstrating that lowering blood levels
of homocysteine actually prevents atherosclerosis and heart attacks.
There is
also no official recommendation as to who should be tested for
hyperhomocysteinemia. The optimal doses of the B vitamins, folic acid, B12, and
B6, required to prevent and treat hyperhomocysteinemia are also uncertain. For
folic acid, a daily dose of 0.8-1.0 mg is probably adequate.
What about antioxidants for heart attack prevention?
Antioxidants are food supplements that have been promoted as preventing heart
disease and stroke. An important early event in the development of a cholesterol
plaque in atherosclerosis is the oxidative modification of LDL cholesterol (low
density lipoprotein) particles in the blood and the subsequent interaction of
this modified LDL with the wall of the coronary artery. This process initiates
the formation of the cholesterol plaque.
Antioxidants that block the oxidative modification of LDL have been shown to
slow the progression of atherosclerosis in animal experiments. Examples of
antioxidants include vitamin E and beta carotene. In humans, observational
studies (studies that observe the frequency of related conditions) have found a
relationship between the dietary intake of vitamin E and lower rates of heart
attacks.
Observational studies provide only circumstantial evidence, however, and
credible evidence is obtained only by way of controlled trials (discussed at the
beginning of this article). Several controlled trials performed to date have
yielded conflicting results on the benefits of antioxidant therapy. These
results may possibly be due to the low doses of vitamin E used, the small number
of patients in the study, or the limited duration of treatment.
The Heart Outcomes Prevention Evaluation study used a high dose
(400 IU per day) of vitamin E over a span of five years in patients with
significant risk factors for heart disease or stroke. This study found no
difference in the occurrence of heart attack or stroke in the group treated with
vitamin E versus those given the placebo. This study demonstrated that
antioxidant therapy does not have any benefit in persons who have or are at high
risk for having atherosclerosis.
Next: How about exercise for heart attack prevention? »
- vitamin B12/folic acid/vitamin B6-oral, Folgard, Folgard RX 2.2, Foltx, Homocysteine Formula - Consumer information about the medication VITAMIN B12/FOLIC ACID/VITAMIN B6 - ORAL (Folgard, Folgard RX 2.2, Foltx, Homocysteine Formula), includes side effects, drug interactions, recommended dosages, and storage information. Read more about the prescription drug VITAMIN B12/FOLIC ACID/VITAMIN B6 - ORAL.
- Homocysteine - Read about the test for homocysteine levels in the blood. High levesl of homocysteine include increased risk of heart attacks, strokes, blood clots, and Alzheimer's disease.
- Stroke - Learn about strokes symtoms like sudden numbness or weakness in the face, arms, or legs, confusion, vision problems, problems with walking or coordination, or severe headache.
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