3 Ways to Make Fruits and Vegetables Even Healthier

Just because Mother Nature packs nutrients into fruits and vegetables more tightly than commuters on a Japanese subway doesn't guarantee that the good stuff will last forever. How you treat produce before you eat it has a big impact on how many nutrients are still there when you eat it. Here's how to handle three summer favorites:

• Keep watermelon out of the fridge. That's a big whew, since there's never room for one anyway. But whole watermelons stored at room temperature deliver more cell-protecting antioxidants (specifically lycopene and beta carotene) than melons that are refrigerated or even fresh off the farm. That's because watermelons continue to ripen and build antioxidants after they're picked; the big chill cuts that process short. For a cool treat, chill the sliced fruit right before serving. (And, of course, store any leftovers in the fridge.)

• Slice fresh fruit yourself. Pre-cut fruit saves time, but it opens the door for vitamin C to escape. Kiwifruit, pineapple, and cantaloupe seem particularly prone to C loss, according to one of our favorite physician-chefs, John La Puma, MD.

• Be gentle with broccoli. Cook broccoli at too high a temperature and you decrease levels of sulforaphane, its main cancer-fighting nutrient. Light cooking, however, actually boosts that good-for-you compound. Cooking broccoli to 140 degrees Fahrenheit is ideal (158 degrees Fahrenheit was the point at which sulforaphane content dropped), but if you don't want to make a science project out of your broccoli, know that lightly steaming it does the trick.