Raw or cooked, boiled or steamed… The way vegetables are prepared can influence their content of vitamins, minerals and other nutrients, according to science.
- “In nutritional terms, there are advantages and disadvantages to cooking vegetables,” according to scientists. “Steaming is the best method to preserve nutrients” because it limits exposure to water and heat.
- Cooking does not always destroy nutrients, on the contrary. It can make certain foods more easily absorbed by the body. This is the case for lycopene, more available in cooked tomatoes, or carotenoids.
- Whether raw or cooked, certain vegetables benefit from being eaten with healthy fats, such as vegetable oils.
Vegetables are an essential source of vitamins, minerals, phytonutrients and fiber, but did you know that how you cook them can influence their nutritional value? A new study, published in the British Journal of Nutritionreveals the best methods to take full advantage of all the nutrients in vegetables.
Cook vegetables or eat them raw?
“In nutritional terms, there are advantages and disadvantages to cooking vegetables”explains dietician Helen Rasmussen, researcher at Tufts University (United States), in a press release. For example, cooking carrots reduces their vitamin C content, a key nutrient for collagen production, but increases the availability of beta-carotene, a precursor to vitamin A, essential for vision and the immune system.
Some nutrients, such as vitamin C and B vitamins, are water soluble and are therefore lost when cooked in water. This is why it is best to eat vegetables rich in these vitamins, such as broccoli and peppers, raw. If you must cook them, opt for methods that use little water, such as steaming or baking. And if you boil them, save the cooking water to make stocks or sauces, rather than throwing away the nutrients it contains.
Note that some nutrients will be lost regardless of the cooking method. “Some vitamins are not very stable. The more a food is exposed to heat, the lower the level of vitamin C, for example.” According to scientists, “steaming is the best method to preserve nutrients” because it limits exposure to water and heat.
Consume vegetables with healthy fats
Cooking does not always destroy nutrients, on the contrary. It can make certain foods more easily absorbed by the body. This is the case of lycopene, a powerful antioxidant which fights against certain cancers, notably prostate cancer. Lycopene is more available in cooked tomatoes than in raw tomatoes, hence the high levels in products like tomato sauce or ketchup.
Other vegetables such as carrots, spinach, mushrooms and peppers release more carotenoids, compounds beneficial to health, after cooking.
Final lesson from the study: whether raw or cooked, certain vegetables benefit from being consumed with healthy fats. “Fat-soluble vitamins (A, D, E, and K) and phytonutrients, such as beta-carotene and lycopene, are better absorbed when consumed with vegetable oil.”
