Many of my clients assumeÂ they should be eating fresh, rawÂ produce to reap the most health perksÂ possible. But the reality is, severalÂ studies have debunked conventional wisdom about the best ways toÂ store, prep, and cook fruits and veggies. Check out these science-backed tips for getting the most nutritional bang per bite from seven of your favorites.
Store watermelon at room temperature
After bringing home a watermelon, many people will stick itÂ in the refrigerator. But according to research from the U.S. Department of Agriculture, keeping it out of the fridgeÂ can significantly boost theÂ potency of its antioxidants and other nutrients. The study found that after watermelonÂ was picked and stored at room temp, levels of the protective phytochemicalÂ lycopene increased by up to 40%, while levels of beta-carotene roseÂ by nearly 140%.
In contrast, the study found that when other types of melons were chilled, their nutrient levels remained about the same. To optimize the longevity of your melons however, the best temp to store them atÂ is a coolÂ 55 degrees. A whole melonÂ will last up to three weeks at that temperature, versus one week in the refrigerator. (Once you slice the melon, leftovers should go in theÂ fridge.)
I enjoy cooking broccoli in a varietyÂ of ways, including stir-frying, grilling, andÂ sautÃ©ing. But one classic study published in theÂ Journal of the Science of Food and Agriculture found that to preserve its nutrients, steaming may be the very best method.
Researchers comparedÂ how boiling, steaming, and microwaving impacted the total flavonoid antioxidant levels of broccoli, and found that steaming had a minimal effect. (Meanwhile microwaving diminished levels by up to 97%,Â andÂ boiling caused a 66% loss.)
To up the appeal of steamed broccoli, toss it with a healthy, flavorful coating, like a bit of sundried tomato pesto, olive tapenade, or tahini. You could also top it with a nut-based sauce, like my favoriteâ€”warmed almond butter seasoned with a bit of fresh grated ginger, minced garlic, and crushed red pepper.
Cook and then chop carrots
I love carrots, but I generally prefer them cooked over raw. As it turns out, that's a good thing, since cooking them significantly boosts their levels of beta-carotene. But be conscious of your process: Research done at Newcastle University found that if carrots are boiled and then chopped, their anti-cancer properties are 25% higher. Thatâ€™s becauseÂ cooking them whole helps lock in their nutrients. If you chop first, you increase the veggie's surface area, while allows more nutrients toÂ leach out into the water as the cook.
The study also found that cooking before choppingÂ preserves more natural flavor. When 100 people were asked to wear a blindfold and compare the carrots, more thanÂ 80% rated those that were cut after cooking as tastier.
Let pears get superÂ ripe
Not all fruits continue to ripen after theyâ€™ve been harvested, but pears do. And research from the University of Innsbruck found that allowing pears to really ripen increases levels of certain antioxidants. If you purchase pears that are firm, store them at room temperature in a fruit bowl. To speed up the process, put them next to bananas, which produce an ethylene gas that accelerates ripening.Â To check if your pear is ready to eat, press on the neck. If it gives, it's ripe.
Pair leafy greensÂ with good fat
In one studyÂ from Ohio State, researchers examined the absorption of several key antioxidants when men and women ate veggies with or without avocado. When lettuce and spinach were paired with the healthy fat, subjects absorbed over eight times more alpha-carotene and 13 times more beta-carotene (which both help fight cancer and heart disease), along with four times more lutein (a nutrient linked to eye health). So whether you whip veggies into a smoothie, toss them on a salad, or cook up some leafy greens, be sure to add a good fat (think avocado, EVOO, nuts, or seeds) to get the mostÂ nutritional benefits.
Stock up on frozen blueberries
In a study from Leatherhead Food Research, scientists tested the nutrient levels in produce that had been sitting in a fridge for three days, compared to their frozen equivalents. Surprisingly, more nutrients were found in the frozen samples. In fact, in two out of three cases, frozen produce packed higher levels of antioxidants, including polyphenols, anthocyanins, lutein, and beta-carotene. The conclusion: Freezing fruits and veggies doesnâ€™t make them inferior. It actually helps them retain vital nutrients.
Let garlic sit after you crush it
If you enjoy cooking with garlic, use this tip to make it even healthier: After crushing, let the garlic "rest" for a full 10 minutes. Research shows that this step helps the garlic retain moreÂ of its anti-cancer powerÂ than when you cook itÂ immediately. Why? Crushing garlic releases an enzyme thatâ€™s otherwise trapped in the cells of the plant. This enzyme, which helps boost levels of other health-promoting compounds, requires 10 minutes to peak. So set a timer let your garlicÂ do its thing.
Meet Cynthia Sass at theÂ HealthÂ Total Wellness Weekend at Canyon RanchÂ AprilÂ 22-24. For details, go toÂ Health.com/TotalWellness.
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Cynthia SassÂ is a nutritionist and registered dietitian with masterâ€™s degrees in both nutrition science and public health. Frequently seen onÂ national TV, sheâ€™s Healthâ€™s contributing nutrition editor, and privately counselsÂ clientsÂ in New York, Los Angeles, and long distance. Cynthia is currently the sports nutrition consultant to the New York Yankees, previously consulted for three other professional sports teams, and is board certified as a specialist in sports dietetics. Sass is a three-time New York Times best-selling author, and her newest book is Slim Down Now: Shed Pounds and Inches with Real Food, Real Fast. Connect with her onÂ Facebook,Â TwitterÂ andÂ Pinterest.