By now you are probably aware of the importance of including a variety of heart healthy vegetables in your diet, but did you know that how you prepare them may impact their nutritional quality?

It seems logical that eating vegetables in their raw form, as nature intended, would be the best way to preserve the nutritional quality of a fruit or vegetable, but research actually shows evidence to the contrary. Numerous studies have examined the effect cooking has on a nutrient called beta-carotene, found in dark green and orange-yellow vegetables, such as carrots, sweet potatoes, squash, spinach, broccoli, romaine lettuce, apricots, and green peppers.

Beta-carotene is converted by the body to vitamin A, which helps protect you from diseases such as cancer and heart disease, as well as depression, arthritis and infertility, just to name a few. It is also one of the few nutrients that becomes more readily available to the body when the vegetable is heated. A study published in the Journal of Agricultural and Food Chemistry showed that cooking carrots increases their level of beta-carotene. Cooking vegetables that contain beta-carotene loosens some of the tough cell membranes which helps release the antioxidants.

Another study published in the Journal of Agriculture and Food Chemistry found that cooking actually boosts the amount of lycopene in tomatoes, a red pigment found predominantly in tomatoes and other red fruits such as watermelon, pink guava, red bell pepper and papaya. Incidentally, a rich tomato sauce is an excellent source of lycopene.

Best cooking methods

When cooking vegetables or fruits some methods are better than others, depending on the vegetable and the nutrient that you want to preserve. A January 2008 report in the Journal of Agriculture and Food Chemistry said that boiling and steaming better preserves antioxidants, particularly carotenoid, in carrots, zucchini and broccoli, than frying. However, you should know that cooking fruits and vegetables does decrease other valuable vitamins and nutrients. Vitamin C is easily reduced through exposure to heat and when cooked in water. But at the end of the day, whether you enjoy your vegetables raw or prefer them piping hot, the most important thing is that you’re eating them!