Homocysteine is an amino acid found in blood that is the by-product of the metabolism methionine, a dietary protein. Too much of it is related to a higher risk of cardiovascular disease.
Multiple epidemiological studies have examined the association between elevated homocysteine levels and cardiovascular disease. Most, but not all, report a strong positive association. Evidence suggests that elevated homocysteine levels may promote atherosclerosis (fatty deposits in the blood vessels) by damaging the inner lining of arteries and promoting blood clots.
How do folic acid and other B vitamins affect homocysteine levels?
Folic acid and other B vitamins help break down homocysteine in the body. Homocysteine levels in the blood are strongly influenced by diet and genetic factors. Dietary folic acid and vitamins B-6 and B12 have the greatest effects on homocysteine levels. Studies have demonstrated that higher levels of B vitamins are related to lower concentrations of homocysteine. Low blood levels of folic acid have been linked with a higher risk of fatal coronary heart disease and stroke. Folic acid and B vitamins can be found in green leafy vegetables and fruits. The American Heart association recommends eating at least 5 servings of these fruits and vegetables daily.
Measurement of Homocysteine level
A blood test is available to measure homocysteine in the blood. It is recommended that this test be done while fasting. Normal levels are generally considered to be below 16 umol/l.
It is important to note there are other diseases associated with increased homocysteine levels. These include renal insufficiency, hypothyroidism, psoriasis, certain malignancies and pernicious anemia. Elevated homocysteine levels may also be associated with certain medications.