A new study has shone light on why science has had a hard time proving that folic acid prevents heart attacks. This powerful B-vitamin has been shown in large, population studies to help reduce the incidence of heart attacks. But in other studies, on heart attack patients, this benefit didn’t seem to exist. Well, we may know why now, and the answer is simple. This discovery reinforces the vital nature of ensuring people at risk of heart problems pay attention to their intake of folic acid.
Researchers in the UK investigated the role that folic acid — known as folate when it’s found naturally in fruits and vegetables — plays in shielding the body from a heart attack. It is known that folic acid lowers “homocysteine” levels in the blood. Homocysteine is an amino acid that, when in high amounts, can be dangerous.
This lowering of homocysteine should, in theory, lower the risk of heart attack. But, for some reason, studies of folic acid have not shown that expected benefit. But the new study has found a surprisingly simple explanation. Lowering homocysteine prevents platelets sticking, which stops blood clots. This is an action that aspirin also performs. So, if people in the studies were taking aspirin, there would be no extra benefit in lowering homocysteine with folic acid.
And they found that aspirin was in fact widely used by participants in the trials. This is because they were mainly conducted in patients who had already had a heart attack or other heart diseases.
Researchers showed that there was a difference in the reduction in heart attacks between the five studies with the lowest aspirin use (60% of people took it) and the five with the highest use (91% took aspirin). In the studies, folic acid reduced the risk of heart attack only by about six percent. But it would have been 15% if aspirin had been taken out of the equation. This comes from 75 studies involving about 50,000 participants and clinical trials involving about 40,000 participants.
Despite being so simple an explanation, it has important implications. We should not be closing the door on folic acid, because this B-vitamin could still be important for people who have not had a heart attack. Because those people may not be taking aspirin. Folic acid could help protect the heart.
A safe dose of folic acid is anything up to 400 micrograms a day. Going above that should only be done with a doctor’s consent. As well, folate is found in high levels in dark green leafy vegetables, oranges, other fruits, rice, brewer’s yeast, beef liver, beans, asparagus, kelp, soybeans, and soy flour.