How you prepare your vegetables can boost their nutrients or destroy them. Here's how to get the most nutrition from your veggies.
egetables are
important weapons in the fight against heart disease, cancer, and a host of
other ailments like stroke, vision problems, and hypertension. That’s why the
U.S. Department of Agriculture says they should make up more than one-quarter
of the foods we put on our plates each day — with many nutrition experts
recommending even more veggies.
But depending on how
vegetables are eaten, the valuable vitamins, phytochemicals, and flavonoids
they possess can be either enhanced or destroyed.
“When you’re preparing
vegetables, you have to be careful in how you cook them because the reality is
that heat always destroys some of the nutrients,” says Sue Gebo, RD, MPH, a
West Hartford, Conn., dietitian and assistant professor at the University of
Connecticut School of Medicine. “But on the other hand, the nutrients in some
vegetables are better absorbed after some cooking.”
Raw-food aficionados
may think that cooking destroys the nutrition in all vegetables, but
this isn’t true. When it comes to tomatoes, for instance, cooking them actually
enhances their healthful properties because heat breaks down the thick cell
walls of this fruit — OK, it’s not technically a veggie, but we treat it like
one — which better releases its nutrients.
Although there are
exceptions, griddle and microwave cooking generally help maintain the highest
levels of antioxidants, while pressure-cooking and boiling lead to the greatest
losses. The advantage of microwaving doesn’t surprise Gebo, who notes that this
process cooks food lightly, just as steaming does.
The problem is that no
single cooking method is best for optimal nutrition. With that in mind, here’s a guide to
bringing out the healthy best in the best-for-you veggies.
Asparagus: Asparagus is
high in antioxidants, folate, and potassium. But because folate is very
sensitive to heat, lightly steaming the stalks is best.
Artichokes: Heat doesn’t
seem to bother these perennial thistles, which are high in both heart-healthy fiber and antioxidants, so cook them any way you
like.
Broccoli: This
disease-fighting cruciferous vegetable is very sensitive to heat, so steam or
microwave it to retain broccoli’s nutritional benefit. If you cook it too long, you
destroy the enzymes that break down glucosinolates into cancer-fighting agents.
This means that though cream of broccoli soup may taste good, it doesn’t
provide the same nutrients as a cup of lightly steamed broccoli.
Carrots: Carrots are high
in beta-carotene, which the body converts into vitamin A, but they're also high
in folic acid, which is very sensitive to heat exposure. Eating carrots raw is
fine, but their nutrients are actually better absorbed after very light
cooking.
Green beans: Green beans have
been found to keep their antioxidant levels after most cooking methods, so feel
free to steam, boil, or microwave.
Spinach: Spinach, along
with other leafy greens, is rich in potassium and high in folic acid. It
loses 64 percent of its vitamin C after cooking, so it’s best to enjoy spinach
raw in a salad.
Tomatoes: Tomatoes are
packed with antioxidant, including lycopene — a potent protector against many types of cancer.
Cooking is actually beneficial to tomatoes, which means the body absorbs more
lycopene from tomato sauce, for example, than from raw tomatoes. If you are
enjoying them raw, sprinkle them with olive oil, as this combo is a
particularly effective way to promote lycopene absorption.