Most health experts would agree that food is best eaten in its natural state—organic, fresh, and unprocessed. While many fruits and vegetables are healthiest when served raw, we were surprised to learn that a few key foods actually contain more nutrients when cooked. Yes, boiling, steaming, or zapping fresh food in the microwave could unlock more nutrients.
A German study found that people who followed a raw food diet had low levels of plasma lycopene, a carotenoid found in tomatoes. According to The New York Times, that's because fresh tomatoes actually have lower levels than cooked varieties. "Cooking breaks down the thick cell walls of many plants, releasing the nutrients stored in them," they explain.
So how do you know which foods to cook or simply dice and serve? We've sifted through the research to pinpoint the healthiest way to prep and eat vegetables at home.
Eat it Raw
Broccoli: Avoid overcooking this vegetable. "When these veg are heated, an important enzyme is damaged, which means the potency of helpful anti-cancer compounds called glucosinolates, are reduced," the BBC reports. If you do choose to cook it, use a microwave. The National Brassica Survey found that stovetop cooking can destroy a powerful antioxidant called glucoraphanin.
Onions: Cooking onion could remove the vegetable's natural juices, which contain cancer-fighting antioxidants, according to a study by Cornell University.
Peppers: Cooking a pepper above 375 degrees fahrenheit reduces its vitamin C content by up to 150%, the National Institutes of Health found. Crunch on it raw to absorb all of its nutrients.
Watercress: Like broccoli, the enzyme in watercress is easily damaged when exposed to heat. Eat it raw for a healthy dose of vitamin C, calcium, and magnesium.
Garlic: Cooking garlic ruins its ability to make allicin, a compound that's believed to help protect your body against cancer and heart disease.
Cook It First
Carrots: Don't dice your carrots. Research suggests that cooking carrots whole before cutting them can boost anti-cancer properties by up to 25%. Boiling them also increases carotenoid levels.
Tomatoes: Cooking tomatoes breaks down the cell walls, releasing nutrients like lycopene, which could protect against prostate cancer and heart disease.
Cabbage: Cabbage contains more antioxidants when cooked rather than eaten raw. According to the Journal of Agriculture and Food Chemistry, boiling and steaming are the best methods to preserve vegetable nutrients.
Asparagus: Asparagus retains more cancer-fighting antioxidants when cooked. A 2009 study found that baking and microwave cooking are far better than boiling to keep nutrients in tact.
Mushrooms: This vegetable has thick cell walls, so cooking is thought to unlock more nutrients as the cell wall breaks down.
Would you change the way you eat vegetables to get more nutrients?