Taking a fresh look at garlic
Few people would want to eat a clove of fresh, odoriferous garlic almost every day for months.
But dozens of residents of Palo Alto and surrounding communities are volunteering to do just that in one of the most unusual, and important, studies on garlic ever done.
During the last 20 years, hundreds of studies have attempted, and failed, to establish whether garlic can help lower cholesterol. But Stanford researcher Christopher Gardner believes that his new study finally will provide some much-needed clarification. Not only will it examine whether garlic supplements, which are among the most popular of all dietary supplements, work. It also may determine whether fresh garlic is better at lowering cholesterol.
Six days a week for six months, 200 healthy adults with moderately high cholesterol will either take one of two popular garlic supplements or eat sandwiches containing fresh garlic. The volunteers will have their cholesterol, blood pressure and antioxidant levels monitored periodically. (Garlic is also purported to help lower blood pressure and raise antioxidant levels.) The study, funded by the National Institutes of Health, will be completed in about two years.
“There is lots of lore about garlic,” says Gardner, of Stanford’s Center for Research in Disease Prevention. “But if you look at the [recent research], there is almost nothing on fresh garlic. People swear by it, but you can’t encourage people to try this unless you have the randomized, double-blind trials.”
In the 1970s and ‘80s, Gardner says, many studies concluded that garlic helped lower cholesterol. But some researchers criticized those studies, saying they were too small or didn’t include a control group. In the 1990s, several scientifically rigorous studies showed that garlic had no effect on lowering cholesterol. However, they were done using garlic supplements, which Gardner thinks may not work as well as fresh garlic.
Stanford biochemist Larry Lawson, a co-investigator with Gardner, has performed chemical analyses on garlic supplements that suggest the way some supplements are made could reduce their potency. For example, the active ingredient in garlic, allicin, sometimes dissolves before it can get into the bloodstream. Or the supplement may pass through the body without dissolving at all.
The Stanford researchers have gone to great lengths to make sure that the chemical composition of the garlic and garlic supplements they’re studying is well understood, Gardner says.
“With a lot of these supplements, we don’t even know what the active ingredient is,” says Gardner. “We are characterizing what is in each of the three [the two supplements and the fresh garlic in the study]. This study may set a precedent on how to look at and evaluate herbs.”
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A clove a day: the search for garlic recipes
Rarely has a research team had as much fun as this one seems to be having.
To persuade volunteers -- who must be from the Palo Alto area, where Stanford University is located -- to enter the study, the Stanford team created and tested dozens of gourmet sandwiches loaded with fresh garlic. Volunteer taste testers were brought in to help evaluate the creations, and six sandwiches were ultimately selected, including researcher Christopher Gardner’s favorite: grilled portabello mushrooms on focaccia.
“We couldn’t give people a clove of garlic a day,” says Gardner. “We knew they would have to love the sandwiches to eat them for six months.”
The researchers still worry, however, that study subjects might grow weary of gourmet garlic sandwiches. So they’re offering a prize to any study participant who creates a garlic sandwich that fellow participants also enjoy. The prize, however, is dubious: Free dinner for two at San Francisco’s Stinking Rose restaurant.
