What is homocysteine?
Homocysteine (say: ho-mo-sist-een) is an amino acid (a building block of protein) that is produced in the human body.
How is a high homocysteine level harmful?
High homocysteine levels in the blood can damage the lining of the arteries. In addition, high homocysteine levels may make blood clot more easily than it should. This can increase the risk of blood vessel blockages. A clot inside your blood vessel is called a thrombus. A thrombus can travel in the bloodstream and get stuck in your lungs (called a pulmonary embolism), in your brain (which can cause a stroke) or in your heart (which can cause a heart attack.) People who have very high levels of homocysteine are at an increased risk for coronary artery disease.
What causes a high homocysteine level?
Homocysteine is normally changed into other amino acids for use by the body. If your homocysteine level is too high, you may not be getting enough B vitamins to help your body use the homocysteine.
Most people who have a high homocysteine level don't get enough folate (also called folic acid), vitamin B6 or vitamin B12 in their diet. Replacing these vitamins often helps return the homocysteine level to normal. Other possible causes of a high homocysteine level include low levels of thyroid hormone, kidney disease, psoriasis, some medicines or when the condition runs in your family.
How is the homocysteine level measured?
Homocysteine is measured using a simple blood test. You don't have to prepare in any special way for the blood test.
If your homocysteine level is too high, you need to lower it, especially if you have blockages in your blood vessels. If you have no other major risk factors for cardiovascular disease and you do not have atherosclerosis (a buildup of plaque in your arteries), your doctor may take a watchful waiting approach and monitor the level closely. If your homosysteine level increases further, you may need to lower it.
While no studies have shown that lowering homocysteine levels helps reduce strokes, heart attacks and other cardiovascular conditions, it is a good idea to lower a high homocysteine level because it is a risk for heart disease.
How can I lower a high homocysteine level?
Eating more fruits and vegetables (especially leafy green vegetables) can help lower your homocysteine level by increasing how much folate you get in your diet. Good sources of folate include many breakfast cereals, fortified grain products, lentils, asparagus, spinach and most beans.
If you don't have enough vitamin B-6 in your diet, foods such as fortified breakfast cereals, potatoes, bananas, garbanzo beans (also called chickpeas) and chicken are good sources. Dairy products, organ meats (such as liver), beef and some types of fish are good sources of vitamin B-12 .
If adjusting your diet is not enough to lower your homocysteine, your doctor may suggest that you take a folate supplement. You may also need to take a vitamin B-6 and vitamin B-12 supplement.
What happens next?
If you start taking folate or vitamin B supplements, you should have your homocysteine level rechecked after 8 weeks. If your homocysteine level remains high, your doctor may have you try a higher dose. You may need to have some tests to see if you have another health condition that causes high homocysteine levels. If you have had a high homocysteine level, you will probably need to have your level checked regularly (2 or 3 times a year).
Written by familydoctor.org editorial staff