VANCOUVER -- Leafy greens are a crucial part of a healthy diet, with kale, spinach and other greens linked to a reduced risks of heart disease, some cancers, and Type 2 diabetes. But behind that crunchy green exterior lies a dangerous risk.

In the last two years alone, the Canadian Food Inspection Agency says there were 32 recalls of leafy greens or related salad products. And all were because of bacteria - specifically E. coli and listeria. 

Both kinds of bacteria can make you severely ill, and for some people, even carry a risk of death. 

James Dickerson, Consumer Reports’ chief scientific officer, says cutting greens out of your diet is not an option. 

“So here’s the challenge - we want people to eat these green vegetables, but they’re easily contaminated by bacteria.”

That bacteria can come from animal feces on the farms produce comes from. Many of the leafy greens we eat are grown in California and Arizona, and for the farmers that grow them, keeping the crop clean comes with challenges. 

Amber Brouillette works on a farm in New York State. She says workers do a lot to keep produce clean. 

“You’re always worried about contamination from animals. If you’re growing leafy greens outside, even just wild birds flying overhead increases the risk of contamination by salmonella and E. coli.”

Farmers keep animals away from their fields, sanitize equipment and boots and wear gloves - but it’s still possible for contaminants to end up in your salad. 

So is this an excuse to stop eating greens altogether? Absolutely not. Dickerson says the benefits far outweigh the risks. 

“One of the best things you can do is cook it,” he advises. “So cook it to the point where it’s wilted.”

Not everyone who is exposed to salmonella, listeria or E. coli gets sick, but pregnant women, older adults, infants, small children, and those with compromised immune systems should carefully consider their options. 

Many labels, especially for packaged salad greens, say the produce has already been washed, sometimes up to three times. But you should still wash it - even the most thorough washes only really remove dirt and grit, and don’t guarantee the greens are bacteria-free.