Does Cooking Affect The Nutrients In Our Food?
Cooking food both degrades and enhances the availability of nutrients. How much nutrients we get from the food we eat depends on the type of food we're eating.
Some foods like broccoli, kale and cauliflower have more nutrients when eaten clean and fresh. Other veggies such as carrots, tomatoes, spinach and eggplants release more nutrients when cooked. In these kinds of veggies, cooking degrades the thick cell walls of these plants, releasing the nutrients stored in them. So it's a matter of knowing which veggies retain more nutrients when eaten fresh, and those that need to be cooked. And this knowledge comes from experience and reading.
Let's talk about veggies. But first, a reality check. No cooking method will preserve 100 percent of the nutrients in a vegetable. Nutrient content is also altered during cooking.
If you want to preserve as much nutrients in a veggie as possible, microwaving is your best bet, according to the expert opinion out there. That's because the short cooking times and reduced exposure to heat in microwaving preserves nutrients much better than frying or boiling. Some studies have found that microwaving is the best method for retaining the antioxidants in garlic and mushrooms. Other studies have shown that only 20 percent to 30 percent of the vitamin C in green vegetables is lost during microwaving — which is less than most cooking methods.
Some vegetables retain a higher concentration of certain vitamins when microwaved. Broccoli is one of these oddballs. A 2007 study looked at the effects of boiling, steaming, microwaving and pressure cooking on the nutrients in broccoli.
The result saw steaming and boiling causing a 22 percent to 34 percent loss of vitamin C in broccoli. On the other hand, microwaved and pressure-cooked broccoli retained 90 percent of its vitamin C.
Generally speaking, however, vegetables are a great source of vitamin C, but a large amount of this vitamin is lost when they’re cooked in water. Boiling reduces vitamin C content more than any other cooking method. For example, broccoli, spinach and lettuce could lose up to 50 percent or more of their vitamin C when boiled.
On the other hand, a study in the Journal of Agriculture and Food Chemistry concluded boiling was better for some veggies such as carrots, zucchini and broccoli compared to steaming, frying or serving them raw. Frying vegetables is the worst method for preserving nutrients in vegetables.
Whatever method one uses to cook food, these nutrients are often reduced during cooking:
- Water-soluble vitamins: vitamin C and the B vitamins: thiamine (B1), riboflavin (B2), niacin (B3), pantothenic acid (B5), pyridoxine (B6), folic acid (B9) and cobalamin (B12)
- Fat-soluble vitamins: vitamins A, D, E, and K
- Minerals: primarily potassium, magnesium, sodium and calcium
Nutritionists said the best way to get the most out of your vegetables is to consume them in a variety of ways. This means eating veggies raw, boiled, steamed, baked or grilled. They said that if you regularly eat a variety of fruits and vegetables, you won't have to worry about the cooking method.
