Eating leafy green vegetables, beans and nuts not only keeps the heart healthy but the B vitamin folate found in them also help blunt the damaging effects of heart stroke, says a new study.
According to the study, the B vitamin folate was found to blunt the damaging effects of heart attack when given in short-term, high doses to test animals.
In the new study, which was conducted by an international team of heart experts at Johns Hopkins and elsewhere, rats fed 10 milligrams daily of folate, also known as folic acid or vitamin B9, for a week prior to heart attack had smaller infarcts than rats who took no supplements.
On average, researchers say, the amount of muscle tissue exposed to damage and scarred by the arterial blockage was shrunk to less than a tenth.
Lead investigator An Moens, M.D., suggests that folate acts as an energy reserve in the heart, "providing much needed energy for muscle contraction, in the form of ATP, at the same time the heart is being starved for oxygen-carrying blood by a blocked artery."
According to Moens, a postdoctoral cardiology research fellow at Johns Hopkins, study results showed that high-energy phosphate levels went down 43 percent in the blood of treated rats, but levels dropped by one-third more in untreated rats.
"With more fuel, the heart kept pumping even though its blood flow was reduced. The smaller heart attacks seemed related to this better energy balance in the heart produced by the folate," Moens said.
In the study, heart function was monitored by more than two dozen key tests, such as echocardiogram and magnetic resonance imaging, as well as by blood analysis before, during and after the heart attack, when blood flow was allowed to resume in the coronary artery that had been blocked.
Among the research team's other findings that backed up the protective effects of folate on the heart were mild, slight dips in systolic blood pressure during heart attack in treated rats, while pressure fell in untreated animals by 25 percent.
Similarly, blood flow was stable in the treated group, but dropped by 40 percent in untreated animals. Post-heart attack buildup of dangerous chemicals, known as reactive oxygen species, was halved in treated rats. And fatal arrhythmias, unstable heartbeats that can immediately follow a heart attack, also went down from 36.7 percent to 8.3 percent in the supplement-fed group.
"We want to emphasize that it is premature for people to begin taking high doses of folic acid," said senior study investigator David Kass, M.D., a professor at The Johns Hopkins University School of Medicine and its Heart Institute.
"Folic acid is already well known to be safe to consume in high doses in the short term, and it is very inexpensive, costing pennies per milligram, so its prospects look promising. But if human studies prove equally effective, then high-dose folate could be given to high-risk groups to guard against possible heart attack or to people while they are having one," said Kass.
The more likely and most practical advantage to ingesting supplements, he said, lies in folic acid's potential to act as a short-term buffer for people who may be having a heart attack and who rush to their local emergency room complaining of chest pain.
He cautioned, "we do not yet know if folate is safe to consume in this high a dose, or how much or how little of it is needed to be effective," citing 25 milligrams per day as the highest dose previously tested safe to consume in adults as.
Kass said that such large amount of folate may also yield unpredictable side effects.
The study is published in the journal Circulation.