For nearly two decades, American thirst for wine has been driven in part by one study after another to show that a regular glass or two seems to have several far-reaching health benefits.
Now a report out of Britain suggests that that string of positive endorsements could be coming to an end. According to news reports, researchers Declan Naughton and Andrea Petroczi of Kingston University in South West London have found potentially hazardous levels of heavy metal ions in many commercial table wines.
In analyzing wines from 16 countries - but not the United States - they found that metal ions were of high enough concentration to pose potential health risks in wines from 13 of the nations. Only wines from Argentina, Brazil and Italy didn't jeopardize health because of their content of metals, say researchers.
The report, in the online Chemistry Central Journal, suggests that a daily 250-milliliter glass of white or red wine could expose imbibers to a potentially higher risk of chronic inflammatory disease, Parkinson's disease, premarture aging and cancer.
The researchers used as safe a value of 1 in calculating the "target hazard quotients" (THQ) of potentially toxic levels of metal ions in wine, a technique developed by the U.S. Environmental Protection Agency. Monitoring by the English researchers generally found levels much higher than that, ranging from 50 to 200 for Hungarian wines and up to 300 for Slovakian wines.
Researchers focused specifically on seven metal ions, including vanadium, manganese chromium, copper, nickel and lead.
Naughton and Petroczi call for more research to pinpoint the source of metal ions showing up in the wine - grapes? soils? insecticides? fermentation tanks? - and to determine the upper safe limits for their consumption. They also found THQ levels above 1 in orange juice and stout.
At UC Davis, meanwhile, Dr. Andrew Waterhouse, intermim chair of the department of viticulture and enology, said the faculty is aware of the study and is analyzing what it may mean. "A couple of things seem a bit odd," says Waterhouse. "Their scoring system seems to have each metal equitable in risk. That's surprising. Lead is more dangerous than copper."
He also found some of the study's findings contradictory, questioned whether the consumption pattern on which it was based it realistic, and concluded that his own early analysis of the data didn't find any reason for alarm.
The university, adds Waterhouse, isn't monitoring heavy metal ions in wine, but that soon could change. "Chemists here would like to do a similar survey of California wines to see what is going on, so we'll talk with some industry folks to see if they want to pursue this or not," Waterhouse says.
The British researchers indicated that they aren't so concerned about the issue that they will stop drinking wine, but they are proposing that levels of metal ions be added to wine labels.