Is the olive oil you’re using really olive oil? According to the New Yorker, chances are good that what’s in that bottle is cut with hazelnut, sunflower seed, or canola oil.

Trafficking in adulterated olive oil has been a problem unto antiquity. Italian authorities are trying to change that, the country’s agricultural minister tells the New Yorker. In April, he announced that 205 olive oil producers out of 757 investigated were guilty of cutting their olive oil with other products, and would be prosecuted. One recent investigation broke up a ring using soy and canola oils colored with industrial chlorophyll and packaged in extra-virgin olive oil tins “emblazoned with pictures of Italian flags or Mt. Vesuvius, and with folksy names of imaginary producers—the Farmhouse, the Ancient Millstones.”

It’s not just made-up brands that are accused; leading companies like Carapelli, Bertolli, and Rubino have been caught with less-than-pure oil. “In 1997 and 1998, olive oil was the most adulterated agricultural product in the European Union,” the New Yorker says. One investigator tells the writer that profits for this snake oil “were comparable to cocaine trafficking, with none of the risks.”

Alison Benjamin over at food blog the Cleaner Plate Club is ticked:

[T]here’s some serious heart disease in [my husband] Blair’s family, and—since we want him around for a long, long time—we’re very aware of what kind of oil we’re using on a regular basis. The idea that someone could be tricking us into a less-healthful alternative just feels like an entire industry is flipping us the bird.

So how can we tell if what we’re buying is really olive oil? According to Squidoo, be suspicious of low prices, and look for imported oils certified by the International Olive Oil Council. Olive oil made in California must also adhere to strict labeling laws.

Trusting the authorities on these matters never leaves a good taste in my mouth, however. Maybe buying local, from a farmers’ market supplier you can talk to face-to-face, is the best option.