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November 8, 2009
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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? »

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Suggested Reading by Our Doctors
MedicineNet Doctors
  • 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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Vitamins & Exercise: Heart Attack Prevention Series

Why Is Childhood Such an Important Time for Bone Development?

Bones are the framework for your child's growing body. Bone is living tissue that changes constantly, with bits of old bone being removed and replaced by new bone. You can think of bone as a bank account, where (with your help) your kids make "deposits" and "withdrawals" of bone tissue. During childhood and adolescence, much more bone is deposited than withdrawn as the skeleton grows in both size and density.

For most people, the amount of bone tissue in the skeleton (known as bone mass) peaks by their late twenties. At that point, bones have reached their maximum strength and density. Up to 90 percent of peak bone mass is acquired by age 18 in girls and age 20 in boys, which makes youth the best time for your kids to "invest" in their bone health.

Building your children's "bone bank" account is a lot like saving...

Read the Juvenile Bone Health article »










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