Strawberries

Strawberries may be a superfood - but they pose a potential risk unless you go organic. In addition to having up to 13 pesticides detected on the fruit, according to an Environmental Working Group (EWG) analysis, conventional "strawberries have a large surface area and all those tiny bumps, which makes the pesticides hard to wash off, so you're ingesting more of those chemicals," explains Dr. Marion Nestle, a professor of nutrition and public health at New York University and author of What to Eat.

If you can, also skip conventional peaches, apples, blueberries, and cherries, which are typically treated with multiple pesticides and usually eaten skins-on.

More from Health.com: 5 surprising things you don't have to buy organic

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