Benefits of Folic Acid Keep Growing

From the WebMD Archives

Dec. 10, 1999 (Atlanta) -- Supplementing the body's natural levels of folic acid could become an effective prevention against some types of coronary disease, according to a study in the December issue of the Journal of the American College of Cardiology.

Proper levels of folic acid have already been linked to the prevention of neural tube disorder birth defects, such as spina bifida. Spina bifida occurs when the fetus's spinal column does not form properly during pregnancy.

The new study is based on folic acid's ability to break down a damaging amino acid called homocysteine that clings to the interior lining of blood vessels. The damage done by homocysteine can heighten the clogging of the vessels, known as atherosclerosis, which is one of several coronary diseases researchers say folic acid could help fight.

"We've known for a short period of time that elevated levels of homocysteine are related to vascular disease," Stephanie Dunlap, DO, medical director of the heart failure and cardiac transplant program at the University of Illinois at Chicago, tells WebMD.

"Homocysteine's effect on the arteries is similar to bad cholesterol, but if you're someone who has vascular disease but a normal cholesterol level, you should ask your doctor to check your homocysteine level and check the folate levels. Folic acid might stop injury to the vessel, which could prevent coronary disease," says Dunlap, who reviewed the study for WebMD.

The study found that homocysteine levels were reduced by 15% after eight weeks of treatment. Seventeen patients received a 10 mg folic acid pill daily, after which the ability of the vessels to adjust for blood flow was significantly improved.

"Our vessels are under stress to get bigger or smaller as needed to adapt for blood flow," says Dunlap.

But the study found that 12 weeks after the treatment ended, the benefits of folic acid supplementation ended also, leading the authors to suggest that long-term supplementation may be necessary.

The study also focused on patients with higher than normal levels of homocysteine, meaning it's unclear whether increased folic acid could benefit people with normal homocysteine levels.


Folic acid levels can be increased through diet or by taking supplements. In 1996, the FDA mandated that grain foods be fortified with folic acid by manufacturers, which included foods such as flour, corn meal, pasta, and rice. Folic acid is also concentrated in orange juice, green leafy vegetables, beans, liver, and other fruits.

This effort was done to lower the rate of birth neural tube defects. The U.S. Public Health Service recommends a daily intake of 400 micrograms of folic acid. The CDC estimates that food fortification has generally increased folic acid intake by 100 micrograms per day, which Dunlap says leaves a lot of room for people to do better on their own.

"I think it's possible to get the right amounts through diet," she says, "if we can go back to eating a better diet. But supplements also work, and there seem to be more reasons over time to increase folate levels."

Vital Information:

  • Elevated levels of homocysteine are associated with coronary disease because it damages blood vessel walls.
  • In a group of study subjects, taking folic acid supplements for eight weeks reduced homocysteine levels by 15%, but once supplementation ceased, so did the homocysteine reduction.
  • Folic acid is found in orange juice, leafy green vegetables, beans, liver, and fortified grains.
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