SUNDAY, April 3, 2005 (HealthDay News) -- New research adds more luster to the sterling reputation of garlic, suggesting its key ingredient prevents rats from developing a kind of lung disease.
Garlic has already been linked to a variety of beneficial effects on health in humans, from reducing blood pressure and cholesterol to treating cancer. The new study found that it seems to improve blood circulation in the lungs of rats and assist breathing.
"It's really amazing," said study co-author David Ku, a pharmacology professor at the University of Alabama at Birmingham who released the findings this weekend at the Experimental Biology conference in San Diego.
However, benefits in rats don't always translate into benefits in humans. And a nutritionist cautioned that it might be "unwieldy" -- if not socially challenging -- to consume two cloves of garlic a day, the human equivalent of what the rats ate.
In the study, Ku and his colleagues tried to induce a form of high blood pressure in the lungs of rats. The human form of the disease, known as primary pulmonary hypertension, puts strain on the heart and can be fatal.
The researchers gave the rats garlic in a powder form and examined its effects on their lungs.
The researchers found that allicin, the active chemical ingredient in garlic, prevented the high blood pressure in the lungs. Garlic without allicin -- it disappears when exposed to heat through boiling -- didn't work.
A related study by Ku and colleagues, also presented at the conference, links garlic to improved heart function.
What to do? Ku acknowledged that more work needs to be done, both in animals and humans. "Garlic is very safe. The question is how to stably deliver it" into the body, he said.
For now, he said, adding garlic to the diet is easy because it isn't toxic, although the amount of allicin in garlic supplements varies widely and can be destroyed by the heat of cooking.
Ruth Kava, director of nutrition with the American Council on Science and Health, said eating two raw cloves of garlic a day could be both physically and socially challenging.
"My advice would be to include garlic in the diet if one enjoys it, but the evidence is not strong enough yet to make it a 'must have' for people with respiratory problems," Kava said. "It's an interesting possibility, but by no means a sure thing. I'd tuck the information away and see if additional research confirms these data."
Learn more about the health benefits of garlic from garlic-central.com.