Before grapes are turned into red wine, the berries slowly mature on the vine, going from green to a dark purple hue. With its roots deep in the soil, the vine sucks up the water and uses it to nourish the individual grapes.
And there’s the rub when it comes to potential levels of arsenic in red wine.
The water in the ground can contain a naturally occurring but poisonous element called arsenic. It is tasteless, colorless, and odorless, and, in large doses, has been linked to various cancer and neurological disorders. The grape vine is particularly good at absorbing it and thus adding it to wine, according to a study that made the cover of the October issue of the Journal of Environmental Health.
University of Washington engineering professor Denise Wilson and her team found that in 65 wines from New York, Washington, and California, the levels of arsenic were higher than what is recommended for drinking water.
Oregon was the one region where levels were on par.
Grape wines are particularly good at sucking up the naturally occurring arsenic in ground water.
The EPA allows drinking water to contain 10 parts per billion of arsenic. The wine samples ranged from 10 to 76 parts per billion, with an average of 24 parts per billion.
“It could be a problem,” Wilson said in an interview about her findings, part of the first peer-reviewed research in decades to look at the arsenic content in food.
But there is no need to panic.
“There is only a health risk if the person is drinking a lot of wine and if they’re consuming other foods with arsenic,” Wilson said.
She produced a companion study that shows a person’s health risk to be a function of the total diet. Many common foods, such as apple juice, organic brown rice, infant formula, cereal bars and canned tuna fish also contain traces of arsenic.
But the Wine Institute of California and several oenologists dispute the idea that naturally occurring arsenic in wine can ever be a health hazard.
“It’s a storm in a tea cup,” said one skeptical oenologist.
The Wine Institute’s Gladys Horiuchi said that if wine were to be held to the same arsenic limit as water, a person would have to drink three bottles a day of wine to be affected. She said Wilson’s results showed that Californian levels are on par with Canadian and international standards for allowable arsenic levels in wine, which are 100 parts per billion.
“The FDA regularly tests wines for harmful compounds, including arsenic, and has found them safe to consume,” she wrote in an email, referring to a fact sheet on the institute’s website.
“It’s a storm in a tea cup,” said Anita Oberholster, an oenologist at the University of California, Davis.
She took issue with the study’s comparison of arsenic levels in wine with drinking water. “We drink much more water than we do wine. Applying a legal limit of arsenic in water to wine doesn’t make sense,” she said.
Oberholster was also critical about the scope of the study. Citing the 65 wines screened in the study, she noted that the United States has more than 10,000 vineyards; even the small ones have each produce three or four different wine labels. To get a reliable measure, more comprehensive research is needed, she said.
“Arsenic is a scary word,” said Gavin Sacks of Cornell University, noting its concentration depends on the soil of the vineyard and not on any production processes or additives. “The problem with a study like this is that the word arsenic immediately captures the public imagination. People get upset, and that opens the door to litigation.”
A class action lawsuit in California against 83 wine labels for high arsenic levels is pending, which the Wine Institute has dismissed as baseless.
That is exactly what Wilson said her research intends to preempt. “The U.S. makes good wines. I know wineries would roll their eyes, but they should consider putting labels on their wines that let the public know about the potential toxins. Otherwise, studies like these open them up to the legal system,” she said.
Bottom line: Worry more about the overall amount of alcohol you may be consuming and less about the tiny trace of arsenic it contains.
This article has been updated.