Cooking Boosts Nutrient Absorption in Five Vegetables, Experts Say

Contrary to the common belief that fresh, raw vegetables are always healthier, some vegetables actually become more nutritious after cooking. Cooking can increase the bioavailability of certain nutrients, making them easier for the body to absorb, though it may reduce heat-sensitive vitamins. Nutritionists interviewed by Martha Stewart’s website highlight five vegetables that benefit from heat treatment.

Tomatoes release more lycopene, a powerful antioxidant, when cooked, especially when combined with a bit of olive oil. Carrots provide more accessible beta-carotene, essential for vision and immune health, after steaming or roasting, though prolonged boiling can reduce vitamin C content. Spaghetti squash, rich in beta-carotene, also becomes more nutritious when roasted or baked with olive oil rather than boiled.

Spinach contains oxalic acid, which inhibits mineral absorption, but cooking reduces this acid, improving the availability of iron and calcium. Quick steaming or sautéing with olive oil and garlic is recommended, along with pairing spinach with vitamin C-rich foods to enhance iron absorption. Mushrooms benefit from cooking as heat breaks down their tough structure, increasing digestibility and the availability of beta-glucans and antioxidants, while also reducing harmful microorganisms.

Experts emphasize that no single preparation method is superior for all vegetables. Boiling can diminish water-soluble vitamins, while steaming, roasting, or sautéing better preserve nutrients. The key is dietary variety, consuming both raw and cooked vegetables to maximize nutrient intake. Ultimately, the priority is to increase overall vegetable consumption rather than focusing solely on raw versus cooked forms.