Should you worry about arsenic in red wine?
Arsenic in large quantities is toxic to humans, but should we be worried about the levels found in wines bottled in the U.S?
ScienceDaily recently reported a new University of Washington study that tested 65 bottles of wine from the four states that produced the most wine in the United States – California, Washington, Oregon and New York. All but one had arsenic levels higher that the 10 parts per billion the United States Environmental Protection Agency allows for drinking water.
The amount of arsenic in the wines tested in the study ranged from 10 to 76 parts per billion, with an average of 24 parts per billion. Wines from the state of Washington had the highest arsenic concentrations, averaging 28 parts per billion, while nearby Oregon had the lowest average of 13 parts per billion.
We decided to ask John Mendelsohn, MD, an emergency room physician and toxicology expert at Falmouth Hospital to shed some light on how dangerous the arsenic in red wine really is.
“This is a case where law, politics and environmentalism meets media,” he says. “It’s a catchy headline, but this comes from a political and legal battle [pdf] regarding winemakers [pdf]. There’s poor science here. It’s an apples to oranges story.”
Here’s why: wine isn’t water.
The wines in question in the study all contained arsenic levels higher than the ten parts per billion of arsenic set forth by the World Health Organization [pdf] for drinking water.
“That is based on a lifetime of exposure,” Dr. Mendelsohn explains. “It’s also based on a 132-pound person, drinking two liters of water a day.”
Arsenic is the twentieth most abundant element in the earth’s crust, so all foods naturally contain at least trace amounts of it. But how much is too much?
Dr. Mendelsohn says that when you consider something called “the uncertainty factor” in toxicology, the real level of arsenic that might be tolerated by humans could actually be 100. The truth is no one knows. All of the science that considers the amount that could cause cancer is based on animal models and anecdotal data, not real tests on people, and the number is deliberately set at the lowest point for humans – with the knowledge the real number could be much higher.
Then there is the tolerable daily intake (TDI) of arsenic, which is again unknown, but has been set at 2 micrograms per kilogram. If you take that calculation and use it as the highest level, then a person who weighs 132 pounds would have to drink 2 liters of red wine a day. A person who weighed 264 pounds would have to drink 4 liters of wine a day – and they would have had to start drinking that amount in childhood for it to be dangerous.
“We have mechanisms in our body to metabolize arsenic,” Dr Mendelson says. “It can accumulate, but it doesn’t because we can clear it from our bodies in reasonable levels.”
Arsenic is believed to possibly cause skin, lung and bladder cancers, but Dr. Mendelsohn says the actual risk of cancer from arsenic is less than 1 percent.
“If you’re drinking two liters of red wine a day, every day for the rest of your life, I don’t think that a .7 percent increase in your cancer risk from arsenic is your biggest problem,” he says.