October 17, 2007
Garlic's heart protective mechanism discovered
An article appearing in the Proceedings of the National Academy of Sciences (PNAS) described research conducted at the University of Alabama at Birmingham which provides a link between cardiovascular disease protection and the the amount of hydrogen sulfide (H2S) released from red blood cells by their interaction with garlic.
Hydrogen sulfide is a gas produced by the body in small amounts that decline with age. The current study is the first to demonstrate that garlic compounds known as polysulfides increase the body's production of hydrogen sulfide. The finding adds to those of another study published online in PNAS on September 18, 2007 which reported a cardioprotective effect of hydrogen sulfide against the tissue and cell damage that occurs following a heart .
In the current research, the team found that a concentration equal to eating two cloves of fresh garlic led to blood vessel relaxation of up to 72 percent in rat arteries due to the release of hydrogen sulfide. “When these garlic compounds are metabolized to H2S in the vascular system, the H2S targets membrane channels and causes smooth muscle cells to relax,” explained lead researcher David W. Kraus, PhD, who is an associate professor at the University of Alabama at Birmingham's Departments of Environmental Health Sciences and Biology. “So a garlic-rich diet has many good effects, and H2S may be the common mediator.”
“The role of garlic compounds in preventing platelet aggregation, which can trigger a heart attack or stroke, and in limiting cancer growth and the progression of several diseases is well documented,” Dr Kraus noted. The current research shows that hydrogen sulfide may be a mechanism through which garlic provides its various effects. The optimal amount of garlic or garlic supplements needed for the greatest benefits will be the subject of future research.