Since Prometheus gave fire to man, we’ve been given the ability to cook our food. In fact, cooking has contributed to the evolution of humanity in a very important way—by destroying potentially pathogenic microbes, cooking enabled man to garner, then store foodstuffs, leaving time for other activities. Cooking also makes foods easier for our relatively small teeth and weak jaws to deal with by softening cell walls in the case of plant matter and protein fibers in the case of animal matter. (Just imagine the effort it would take to chew through a piece of raw chuck roast). Not to mention, how much tastier cooking can make some foods! (Again, compare that piece of raw chuck roast that you gave Fido the other night to the luscious beef stew that you made from the rest).
Cooking makes some nutrients more bioavailable and can also inactivate some naturally occurring toxins. Since cooking begins the process of breaking down plant cell walls, some nutrients that are otherwise sequestered inside of the cells are released and available to be absorbed by the body. However, some nutrients are lost in the cooking process, most notably the very fragile vitamin C and enzymes, which are rendered useless with heat. Eating cooked foods all of the time can be taxing on the digestive system.
Raw and especially fermented foods contain valuable enzymes, which can assist in the digestive process. Without this enzymatic help, much of your food doesn’t get digested until it reaches the small intestine 4 to 6 hours later, where it meets digestive enzymes made by the pancreas. Enzymes present in raw and fermented foods can facilitate digestion as soon as you break those cell walls open with your teeth. Additional churning in your stomach allows those enzymes to do even more work. So by the time the food reaches your small intestine hours later much of it has been digested, giving your pancreas an easier time.
Only eating cooked foods increases energy and resource demands for digestion by necessitating digestive glands, such as the pancreas, to secrete an abundance of digestive enzymes. Over-stimulation of the pancreas can lead to its exhaustion and therefore decreased digestive capacity over time. Eventually, this can result in illness and decreased resistance to stress. On a short term, practical level, this equates to feeling tired and lethargic after eating meals.
Grains, legumes, and certain vegetables should be enjoyed cooked. Which vegetables?? Glad you asked…
You may want to reconsider eating that spinach salad everyday. Certain vegetables including spinach, chard, beets, beet greens, and parsley are high in an anti-nutrient called oxalic acid. Oxalic acid binds to calcium and other minerals and prevents their absorption. 80% of kidney stones are made of calcium oxalate, so if you're at high risk for them, this is especially a consideration for you. Cooking significantly reduces oxalic acid if the cooking water is drained.
Cruciferous vegetables, including broccoli, collards, kale, mustard, cabbage, brussel sprouts, and cauliflower contain goitrogens, which can interfere with thyroid function. The thyroid gland is a very important endocrine gland that regulates metabolism, energy utilization, and calcium homeostasis. Again, cooking reduces goitrogens.
Luckily, humans are pretty smart animals (most of the time), and vegetables that are best cooked from a nutritional standpoint usually taste better cooked. (When’s the last time you ate a raw potato? blecch.) Even raw spinach leaves that unpleasant film on your teeth. That film, by the way, is oxalic acid combining with calcium, forming an insoluble (can't dissolve) solid on your teeth.
As you can see, some nutrients are made more available through cooking while some are more available when uncooked. So it's a good idea to enjoy them raw sometimes and cooked others to make sure you obtain the full spectrum of nutrients.
Almost all traditional diets incorporate a combination of raw, fermented, and cooked foods. Raw foods come in the form of not only vegetables, but meat and fish as well. Think sashimi, beef carpaccio, steak tartare, kitfo (Ethiopian minced raw beef), ceviché, Hawaiian poke… But please exercise caution and procure ingredients from high quality sources when eating raw meat or fish.
So do like our ancestors and eat a variety of raw, fermented, and cooked foods for maximum nourishment and enjoyment of your food!
Give It A Try!
The weather's getting warmer and spring vegetables abound, so here's a recipe that incorporates both raw and cooked foods while taking advantage of the season's bounty. Enjoy!
Salmon Cobb Salad with Spring Vegetables and Buttermilk Dressing
1 large head of lettuce, or several heads of baby spring lettuces, cut or ripped into pieces
4-5 radishes, sliced thinly
½ bulb fennel, sliced thinly
1 cup snap peas, lightly blanched
½ fennel bulb, thinly sliced
1 avocado, peeled, and cut into slices
4 hard-cooked eggs, cut into quarters
8 oz. salmon fillet
¼ c spring onions, minced
buttermilk dressing to taste (recipe to follow)
Preheat broiler. Pat salmon filet dry. Put a thin coat of olive oil on salmon and sprinkle with salt. Place salmon onto a broiler-proof pan and broil for about 6-8 minutes, just until salmon is still medium-rare. Remove from pan and allow to cool. Flake the salmon into large chunks with a fork and set aside.
Season the eggs and avocado with salt. In a large bowl, gently combine all of the vegetables except the avocado. Toss with buttermilk dressing and salt to taste. Arrange the vegetables on a serving platter, adding the eggs, avocado, and salmon. Toss ever so gently. Sprinkle with spring onions.
1 cup mayonnaise
¾ cup buttermilk
1 T lemon juice
2 T each spring onions and green garlic, minced
1 T parsley, minced
1 t mint, minced
Whisk all ingredients together. Dressing should be thin—if it’s too thick add more buttermilk. Refrigerate for up to one week.