Some foods (veggies!) retain their nutrients when eaten raw and some lose their nutrients when cooked. And some people say steaming is not okay! Could you clarify a little bit about that?
I hope this blog finds everyone well and healthy! What a fabulous question as many of us have been cooking more at home AND local veggies are soon to be more available and plentiful. Let’s look at how cooking (or not) affects the nutrients in veggies. When talking about nutrients in veggies we are mainly talking about phytonutrients. Phytonutrients are beneficial plant compounds that play a role in how our bodies work (in our cells and body systems). These are in addition to the vitamins and minerals found in veggies.
In general, cooking vegetables more often increases phytonutrients, mainly antioxidants (think beta-carotene, lycopene, lutein), vitamins, and minerals. Cooking breaks down the walls of the cells in vegetables which “lets out” the antioxidants. Chopping has a similar effect (so does chewing!). Cooking and chopping can make it easier for our bodies to absorb the beneficial nutrients. The key is cooking for a short amount of time and not at a high heat. Examples of these vegetables include tomatoes, winter squash, butternut squash and dark leafy greens (kale, spinach), and cruciferous vegetables (cauliflower, broccoli, and cabbage).
Cooking in water does increase nutrient loss. The more water used and the longer cooked, the more nutrients are pulled out of the vegetable. Boiling and pressure cooking are the two main methods of cooking in water. You can use the cooking water for broths, soups, stocks, sauces, stews etc. to make sure you get all those lost nutrients.
When steaming, though water is used, the vegetables are not necessarily submerged in the water, this means that the nutrients are kept. Cooking in the microwave (without water, if possible and only until tender), roasting, stir-frying and grilling are what we call dry cooking methods and will also retain more nutrients than cooking in water.
BOTTOM LINE: Eat veggies often, eat a variety and prepare them how you enjoy!
Here are a few fast facts focusing on specific veggies:
The longer tomatoes are cooked the more nutrients are boosted. Processed (such as canned sauce or paste) tomatoes have the most lycopene and more flavor when compared to fresh.
To preserve the most nutrients from lettuce it is best to rinse with water, dry and then rip/chop into bite size pieces after shopping and before storing. This increases antioxidant activity.
There are a handful of veggies that are best when eaten as soon as possible, preferably from local sources (as they do not have to travel as far, and nutrients can be further saved). Artichokes, arugula, asparagus, broccoli, Brussels sprouts, kale, lettuce, parsley, mushrooms, spinach.
To maximize the nutritional benefits of garlic try preparing it 10 min before cooking (pressing, chopping, slicing, mashing). Let it set out for 10 minutes before adding to heat.
More nutrients are protected in carrots when they are cooked whole instead of cutting up or eating raw.
Did you know that beet greens have a stronger nutrient punch than the beets themselves?
As for artichokes, they have just as many nutrient properties whether they are fresh, canned or jarred.
Who would have thought that thawing berries in the microwave saves more nutrients, specifically vitamin C, than thawing on the counter or refrigerator?
When buying broccoli go for the whole head instead of pre-cut. This will preserve the nutrients.
**I highly recommend the bookEating on the Wild Side: The Missing Link to Optimum Healthby Jo Robinson. The book was used in creating this blog.