Every time I go to the supermarket I try to weigh the pros and cons of buying organic over non-organic. My poor wallet always roots for the Plain Jane box of blueberries, but my health-conscious side votes to splurge—writing about health is such a huge part of my job, and I’ve read extensively on the topic of organic foods.

But maybe it’s better to be frugal after all. A new  Stanford University “meta-review” of 237 studies found no real nutritional benefits from eating organic food. The findings don’t discredit organic foods entirely: Going organic lessens your exposure to pesticides in produce (which can be particularly dangerous for young children) and to bacteria in meat. Still, the survey should reassure some consumers that they aren’t missing out when they go for non-organic fruits and veggies.

So, how do we know what to buy at the grocery store? As a general rule, if something has a skin you discard—sweet corn, oranges or avocados, to name a few—the bulk of the pesticides come off when you remove the outer layer, so it’s fine to buy conventional produce. (Although, the Stanford study notes that the pesticide levels of all foods reviewed generally fell within the allowable safety limits, it’s better safe than sorry.) And this guide from Prevention describes 12 fruits and veggies to buy organic and 15 naturally clean ones to help take the guesswork out of your next trip to the supermarket. It might even help slash the bill.