Last summer, I told you about a study of women who used folic acid. In just 21 days, the women decreased their homocysteine levels. (Homocysteine is an amino acid—which if you have too much—puts you at risk for heart disease). They also lowered both their systolic and diastolic blood pressure. And they improved their bodies' response to sugar. Not bad for 21 days, right?

Well, I've recently found a study that might explain why these women experienced such robust gains in heart health in just 21 days.

Scientists from China gave folic acid to mice with diabetes. (Why'd they use diabetic mice, you ask? Well, diabetes contributes to heart disease. It weakens blood vessels and can cause blood clots. In fact, most people who have diabetes don't die of too much sugar. They die of heart disease because the sugar's damaged their blood vessels.)

The scientists divided the diabetic mice into two groups. One group received a daily dose of folic acid. (They received a daily folic acid supplement equivalent to taking 5 mg per day if you weight about 150 pounds.) The second group of mice received no supplementation.

After one month, scientists found that mice given folic acid reversed harmful damage (caused by diabetes) to the lining of their blood vessels. Scientists also saw marked improvements in a protein pathway that dilates blood vessels and prevents clotting. On the other hand, the mice not given folic acid did not experience these improvements.

Bottom line: here's more proof that folic acid's an important tool in warding off heart disease, especially if you have diabetes. You can get some from the foods you eat. I'd skip the fortified cereals and other processed foods. Instead, eat plenty of green vegetables like spinach, broccoli, and asparagus. Also, you can take a folic acid supplement. Go for 800 micrograms (mcg) of it per day. Also, make sure to take folic acid along with 1,000 mcg of vitamin B12.