Three vegetables you should always cook for boosted nutrition

I recently read in the news a story about a woman who claimed her raw, vegan diet cured her breast cancer. Tragically, the cancer spread while she was on this extreme diet, and she eventually succumbed to the disease.

Worse yet, in my view, her diet probably harmed her chances of a cure ¾ rather than helped it.

As I always discuss, the vegan/vegetarian diet simply does not provide you with the necessary amounts of nutrients needed for optimal health — such as vitamin D. (And study after study has shown that vitamin D protects against a host of chronic diseases, including cancer, as I reported again just last week.)

And this poor woman certainly wasn’t doing herself any favors by following a raw diet. In fact, research shows cooking improves the concentration of several key nutrients…including the all-important carotenoids, which provide key protection against many chronic diseases, including cancer.

Raw isn’t always better

First of all, plant cells, as in all vegetables, have double walls of indigestible fiber. These double walls make the plants strong, with the ability to stand upright and withstand the weather. (Remember, plants are sessile, or immobile. They can’t just up and move to seek shelter from bad weather…or get out of the sun and into the shade. They are the shade! For this reason, their cells are built strong to endure all types of conditions.)

Keep in mind, cooking vegetables (heat) does reduce the absolute nutrient content in some cases. But it also breaks down the hard, double-walled plant cells, making it much easier to eat, chew, digest, and absorb even more of the nutrients still present.

In the mid-1980s at the United States Department of Agriculture (USDA) Agricultural Research Station, I tested this process by observing the effects of cooking on the carotenoid content of vegetables — including broccoli, carrots, and tomatoes.

We found cooking the vegetables in a microwave for about six minutes made them tender, easier to chew, and easier to swallow and digest. Yes, it did reduce the vegetables’ absolute nutrient composition a bit. But study participants still got more carotenoids into their bloodstream after eating the cooked vegetables.

More current scientific research confirms our findings from back in the 1980s. In fact, here are three vegetables you should always cook for optimal digestion and nutrition:

  1. Carrots

Just as we found with my experiments at USDA years ago, research shows if you boil carrots whole before slicing, it makes them easier to cut and preserves their nutritional value.

In fact, a 2008 study in the Journal of Agricultural Food Chemistry found that boiling carrots until tender boosted their concentration of carotenoids by 14 percent. And anything that boosts your absorption of carotenoids is a good thing. My award-winning research at the National Cancer Institute (NCI) found that many active carotenoids in foods provide powerful protection against cancer.

You can sauté carrots in a little grass-fed butter and/or olive oil to make a nice side dish. Or simply add them to stews, soups, or salads.

  1. Mushrooms
    Even edible mushrooms can harbor small amounts of toxins (most notably hydrazine, a group of chemical compounds considered to be carcinogenic). But an easy, thorough sauté can quickly destroy these trace chemicals.

Plus, according to the Department of Agriculture’s nutrient database, a cup of cooked white mushrooms has about twice as much muscle-supporting potassium, heart-healthy niacin, immune-boosting zinc, and bone-strengthening magnesium as a cup of raw ones.

Again, you can sauté mushrooms in grass-fed butter and/or olive oil. They’re like little sponges and will soak up the healthy essential oils and other spices, such as garlic and thyme. They also release a lot of water, so for the best flavor, let them cook down slowly.

You can also add cooked mushrooms to other dishes to add a little variety to homemade sauces, over or in eggs, or in a stir-fry, or as a topping for a juicy, grass-fed burger or steak.

In Italy, the gathering and preparation of mushrooms is a great culinary art. I have even seen Italian chefs prepare a little meat sauce to use as a topping for large, cooked mushroom “steaks.”

During the summers of 1963, 1972, and 1976, I vividly remember gathering wild mushrooms with my cousins on our family visits to the slopes of the Apennine Mountains. The lush greenery contrasted beautifully against the stark white snow that lingered on the peaks as we hiked higher and higher. We couldn’t wait to get those wild mushrooms back home, cook them up, and enjoy them as a nice, healthy meal. It doesn’t get much fresher than that!

  1. Spinach
    It’s quite common nowadays to see raw spinach salads featured on a restaurant menu or as an option at a salad bar. But you’ll get more nutrients, especially essential minerals like calcium and iron, by eating spinach after cooking.

And — remember — you should strive to get your calcium and iron from dietary sources, not nutritional supplements. (Research links calcium and iron supplements with increased risks of chronic diseases, including cancer and heart disease, as I reported on the latest study last week.)

Raw spinach is also loaded with oxalic acid, which can block the absorption of minerals from your food. Although many people’s bodies can get rid of this substance just fine, I recommend you limit your intake of raw spinach if you have kidney issues, as it’s been shown to cause kidney stones.

However, studies show that cooking spinach briefly in boiling water reduced oxalic acid by 40 percent, which makes it easier to digest and improves nutritional value.

You can also blanch fresh spinach leaves in boiling water before preparing them for consumption. This makes it easy to add to an array of meat and seafood dishes for “Florentine” style cooking.

Tomorrow, I’ll tell you all about cooking two more delicious disease-combatting vegetables. I’ll give you a hint: one is red and one is green. Take a guess and stay tuned to tomorrow’s Daily Dispatch for the answer.



“Five vegetables that are healthier cooked,” Consumer Reports ( 9/17/2017