What is homocysteine?

Homocysteine is an amino acid that is made by the body. It is also in some foods. Amino acids are the building blocks for proteins. High levels of homocysteine in the blood have been linked to a higher risk of heart disease and stroke. A high level of homocysteine may:

• Increase your risk for blood clots.
• Damage the cells lining the inside of your arteries.

The damage to your arteries and blood clots may increase your risk for atherosclerosis, which happens when fatty deposits called plaque buildup in blood vessels and make them narrower.

What causes high levels of homocysteine?

Things that may cause high levels of homocysteine are:

• Aging
• A medical problem called homocystinuria that keeps the body from getting rid of homocysteine
• Kidney disease
• Low level of thyroid hormones
• Not enough folic acid, vitamin B6, or vitamin B12 in the diet
• Smoking
• Some medicines

How can homocysteine levels be lowered?

A healthy diet can lower homocysteine levels. Three nutrients can help keep homocysteine in check: folic acid, vitamin B6, and vitamin B12.

• Folic acid is found in green leafy vegetables, oranges, and fortified cereals.
• Vitamin B-6 is in many foods, including bananas, potatoes, and fortified cereals.
• Vitamin B-12 is found in animal products such as meats, poultry, fish, and eggs. It is also in fortified cereals.

Will I lower my risk of heart attack if I lower my homocysteine level?

There is no proof that folic acid and B vitamins prevent heart attacks and strokes. If you are at high risk for heart disease, your healthcare provider can check your homocysteine level with a blood test. If your levels are high, your provider may advise you to be sure to get enough B vitamins in your diet. However, other risk factors and your total diet play a role as well.