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During the past few years, elevated blood levels of homocysteine have been linked to increased risk of premature coronary artery disease, stroke, and thromboembolism (from venous blood clots), even among people who have normal cholesterol levels.
Homocysteine (referred to as the H factor) is a chemical (a sulfur-containing amino acid) found in our blood. It is a product of the metabolism of protein in our bodies. Evidence suggests that homocysteine may promote atherosclerosis (fatty deposits in blood vessels) by:
Blood for measuring homocysteine levels is drawn after a 12-hour fast. Levels between 5 and 15 micromoles per liter (µmol/L) are considered normal. Abnormal concentrations are classified as moderate (16-30), intermediate (31-100), and severe (greater than 100 µmol/L).
Homocysteine levels in the blood are strongly influenced by diet, as well as by genetic factors. The dietary components with the greatest effects are folic acid and vitamins B6 and B12.
Folic acid and other B vitamins help break down homocysteine in the body. Several studies have found that higher blood levels of the B group vitamins are related, at least partly, to lower concentrations of homocysteine.
Dietary supplementation with folic acid can reduce elevated homocysteine levels in most people. The usual therapeutic dose is 1 mg/day. Vitamins B6 and/or B12 can be added to the regimen, which should be continued permanently.
Some doctors routinely recommend that patients known to have atherosclerosis take B vitamin supplements without being tested to determine whether their homocysteine level is elevated. They reason that since supplementation is harmless and since elevated homocysteine levels might be a factor, testing is not worth the bother or expense.
The consumption of foods rich in folic acid and to a lesser extent vitamins B6 and B12 will also assist in lowering blood homocysteine levels. Nothing is better than eating lots of fresh fruits and vegetables when it comes to keeping your homocysteine levels low. You need to eat about five servings of a variety of different fruit and vegetables per day. If this all sounds a bit much here is what it means in practice.
A simple and delicious way to lower your homocysteine level by at least 10% in four weeks.
Here is another selection. This one will give you the bare minimum of 400 mcg of folate each day.
Unfortunately most people eat less than half the needed amounts of fresh fruits and vegetable each day. In the USA less than 15% of the general population eat five servings of fruit and vegetables a day.
In Britain the average consumption of fruit and vegetables is around two to three, while the intake of folic acid is only 239 mcg per day. This is well less than the required 400 mcg per day.
Good food sources of the required vitamins and minerals are:
Try not to overcook the vegetables. Most of the vegetables should be cooked (if at all) for the shortest amount of time - until they are hot, but still crunchy. Steaming or stir frying is better than boiling as the nutrients don't leach into the water.
Here's a guideline on how long it takes to get the vegetables hot and still crunchy, with some of the folic acid still intact.
Broccoli/cauliflower 3 minutes
French Beans 3 minutes
Spinach 1 minute
Cabbage/greens 2 minutes
Many cultures have the habit of overcooking the vegetables (a habit developed when it was necessary for hygiene purposes - to kill off microbes). The trouble is that overcooking destroys the nutrients in the food.
There is a difficulty with getting enough nutrients from the food we eat. Research clearly shows that folic acid from food alone is not nearly as effective as folic acid from supplements. Most researchers are now saying "Eat right and take a multivitamin".
Lowering the blood concentration of homocysteine has been shown to reduce the risk of adverse cardiovascular events among people with homocystinuria. Studies have not yet determined whether lowering homocysteine levels reduces the incidence of heart attacks or strokes among people with mildly elevated homocysteine levels, but many experts believe that scientific studies will, in time, demonstrate that it does.
This belief has been strongly supported by a four-year study in which 101 men with vascular disease were given supplementary doses of folic acid, B6, and B12. Ultrasound examinations of their carotid arteries found a decrease in the amount of carotid plaque in their arteries, with the greatest effect in those whose homocysteine levels had been highest before the treatment began.
It is recommended that healthy adults eat more fresh fruits and vegetable, eat less saturated fat and cholesterol, and take one multivitamin daily. One quality multivitamin will supply 400 mcg/day of folic acid in addition to vitamins B6, B12, and other important vitamins.
These are all crucial steps in preventing heart attacks and strokes.
Booth, G.L, and Wang, E.L, 2000, with the Canadian Task Force on Preventive Health Care. Preventive health care, 2000 update: Screening and Management of Hypohomocysteinemia for the prevention of Coronary Artery Disease Events. Canadian Medical Association Journal 163:21-29.
Hackam, D,G. and others. 2000, What level of plasma homocyst(e)ine should be treated? Effects of Vitamin Therapy on Progression of Carotid Atherosclerosis in Patients with Homocyst(e)ine Levels above and below 14 micromol/L. American Journal of Hypertension13:105-100.
Holford, P. and Braly, J. 2003,The H Factor: Homocysteine - the Biggest Breakthrough of the Century. Piatfus.
Loralie, J. and others.2000, Hyperhomocyst(e)inemia and the Increased Risk of Venous Thromboembolism. Archives of Internal Medicine 160:961-964.
Quinlivan, E.P. and others. 2002,Importance of both Folic Acid and Vitamin B12 in Reduction of Risk of Vascular Disease. Lancet359:227-228, 2002.
Ridker, P.M. and others. 1999, Homocysteine and Risk of Cardiovascular Disease among Postmenopausal Women. JAMA 281:1817-1821.
Schnyder, G. and others. 2002, Homocysteine-lowering Therapy with Folic Acid, Vitamin B12, and Vitamin B6 on Clinical Outcome after Percutaneous Coronary Intervention. The Swiss Heart Study: A randomized controlled trial. JAMA 288:973-979.
Tanne, D. and others. 2003. Prospective Study of Serum Homocysteine and Risk of Ischemic Stroke Among Patients with Pre-existing Coronary Heart Disease. Stroke34:632-636.
Verhoef, P. and others. 1997. Plasma total Homocysteine, B Vitamins, and Risk of Coronary Atherosclerosis. Arteriosclerosis, Thrombosis, and Vascular Biology17:989-995.