A virtual wellness program offered by the National Institute for Fitness and Sport and provided to you through your employer.

Homocysteine and Heart Disease

Homocysteine (pronounced homo-SIS-teen) is an amino acid found normally in the body.  Its metabolism is linked to that of several vitamins, especially folic acid, B6, and B12.  Deficiencies of those vitamins may cause elevated levels of homocysteine.

Homocysteine and Heart Disease

Various studies have found that persons with elevated levels of homocysteine in their blood are at an increased risk of heart and vessel disease.  Theses studies include the Physicians’ Health Study, the Tromso Study from Norway, the Framingham Heart Study, and a meta-analysis of nearly 40 studies.

Some studies indicate that persons with elevated homocysteine levels tend to also have other risk factors for heart disease, especially smoking, high blood pressure, and high blood cholesterol.

Several theories exist to better understand how an elevated homocysteine level affects the development and progression of heart disease.  Keep in mind; these are currently only theories with little research to back them up.

• A high level of homocysteine may be involved with the process called atherosclerosis, the gradual buildup of fatty substances in the arteries. 

• Homocysteine also may make blood more likely to clot by increasing the stickiness of blood platelets.  Clots can block blood flow, causing a heart attack or stroke. 

• Increased homocysteine may affect other substances involved in clotting as well.

• Higher homocysteine levels may make blood vessels less flexible—and so less able to widen to increase blood flow. 

What Determines Homocysteine Levels

Two key factors affect a person’s homocysteine level.  Genetic factors help regulate the level of homocysteine in the blood.  For instance, genetic flaws (mutations) can affect homocysteine’s metabolism. 

The level of homocysteine in the blood also is affected by the consumption of vitamins, especially folic acid, B6, and B12.  Data from the Framingham Heart Study show that only 30-40% of the population is getting 200 or more micrograms of folic acid in their diet.  The data indicated that for many persons an intake of at least 400 micrograms was needed to keep homocysteine levels from becoming elevated.

Data also indicate that homocysteine levels are higher in older persons than younger ones, and in women after menopause than in those before. 

Sources of Folic Acid, B6, and B12

Folic acid – citrus fruits, tomatoes, spinach, asparagus, broccoli, green peas, orange juice, lentils, black-eyed peas, lima beans, pinto beans, navy beans, grain products, brussel sprouts, greens, avocado, strawberries, and melon.

Vitamin B6 – meat, poultry, fish, bananas, baked potato, watermelon, salmon, turkey, liver, chicken, whole grain cereals, egg yolks, and avocados

Vitamin B12 – meat, poultry, fish, and milk and milk products, oysters, and liver

What Lies Ahead

It is not yet definitely known if elevated homocysteine is a risk factor for heart disease—that is, if it really increases a person’s chance of developing heart disease.  Known risk factors for heart disease are age (being 45 or older for men; 55 or older for women), a family history of early heart disease, high blood pressure, high blood cholesterol, smoking, obesity, physical inactivity, and diabetes. 

Until more research is done, Americans can protect their health by following a heart-healthy food plan.  Those concerned about homocysteine should talk to their doctor. 

Source: National, Heart, Lung, and Blood Institute