Large Medical Study Concludes
Folate Decreases Risk for High Blood Pressure

Women who get large amounts of the vitamin folate from food and supplements have a sharply lower risk of developing high blood pressure, according to researchers from Brigham & Women's Hospital and Harvard Medical School in a study of 150,000 women.

In the first large study to explore the link between folate and hypertension, women ages 27 to 44 and ages 43 to 70 recorded their folate intake over an eight-year period. Younger women who consumed at least 1,000 micrograms of folate per day — or 2 1/2 times the recommended daily allowance — were 46% less likely to develop hypertension than women who consumed less than 200 micrograms. Older women saw a less pronounced yet significant 18% reduced risk of high blood pressure after consuming 1,000 micrograms of folate each day.

The study, published in the Journal of the American Medical Association, concluded that women who got only got folate from food, instead of from supplements, had difficulty attaining high enough levels to lower blood pressure.

Hypertension affects an estimated 65 million individuals in the U.S. and many more worldwide. The purpose of this study was to determine whether higher folate intake is associated with a lower risk of hypertension.

"The theory," says CBS News medical correspondent Dr. Emily Senay, "is that folic acid somehow keeps blood vessels supple, or less stiff, and so helps keep blood pressure down."

Other research has shown that up to 70 percent of birth defects of the brain and spine, and many cases of Down Syndrome can be prevented by maintaining adequate folate levels before and during pregnancy. Studies have also shown folate to be important in preventing early miscarriage.

Foods as oranges, dark green leafy vegetables, beans, legumes, liver and eggs are highest in dietary folate. In the United States, folic acid is added to cereal and flour products to help prevent birth defects.

• Additional studies are needed to determine whether folate intake has a direct, causal role in risk reduction for hypertension.
• Because this was an observational study, it is possible that other factors may be responsible for the reduction in risk. People with a high intake of one nutrient are likely to have a high intake of several nutrients, and may generally have a healthy lifestyle.
• Intake of more than 1000 mcg/day of folate can hide symptoms of B12 deficiency. A blood test can measure serum B12, or see if methylmalonic acid is elevated as a proxy for functional B12 shortage. Oral supplementation with 1000 mcg/day of B12 corrects or protects against most cases of deficiency (except those due to metabolic or serious malabsorption issues). If untreated, B12 deficiency can result in nerve damage.
• This article is not intended to replace the advice or attention of your doctor or other health care professional. Do not stop taking medications or start taking a nutrition supplement without first speaking to a qualified health care professional.