Here’s how to maintain a seasonal diet or raw and cooked foods that promotes digestive system health.
Raw or Cooked?
Years after paleo and keto have faded from headlines, the conversation about whether eating raw or cooked food is better still rages on. The reality, according to the science, is that they are both beneficial and our ancestors enjoyed both.
Take broccoli for example.
Some studies suggest that raw broccoli is better because heat breaks down an enzyme in this cruciferous veggie called myrosinase. This enzyme breaks down broccoli into cancer-fighting and ulcer-reducing sulforaphanes that have elevated broccoli to superfood status.
On the other hand, perhaps an even more health-promoting nutrient, called indole-3-carbinol, is processed only when cruciferous vegetables (broccoli, cauliflower, cabbage, and more) are cooked. Indole 3-carbinol has been shown to stop pre-cancerous prostate cells from becoming malignant.
This conflicting broccoli science suggests that you are damned if you cook, and damned if you don’t!
In this article, I’ll attempt to make the case that the issue is not whether we should eat raw or cooked veggies, but rather how to maintain a seasonal diet that promotes digestive system health.
The Benefits of Cooked Food
The logic that our ancestors only ate raw food has some major flaws. Numerous studies suggest humans have been cooking for almost 2 million years.
And cooking has plenty of benefits. It softens indigestible cellulose, allowing nutrients to be released that may not be when foods are eaten raw.
For example, carrots release more beta-carotene when eaten cooked rather than raw. Or consider tomatoes: In one study, after a tomato was cooked for 30 minutes at 190 degrees Fahrenheit, lycopene antioxidant levels rose by 35%. Lycopene is linked to a reduced risk of cancer and heart attacks.
Another study followed 198 adults who ate a raw food diet and found that they had high levels of beta-carotene in the blood, which gives much of the color to veggies like carrots and peppers. Their vitamin A levels were normal, but their lycopene levels were actually low, suggesting again that lycopene, an antioxidant more powerful than vitamin C, is more available from cooked veggies.
The Benefits of Raw Foods
The notion that we should only eat cooked foods is also not supported by science. Dental calculi from pre-agricultural societies had evidence of a diverse plant-based diet, as well as cooked foods.
One of the clear benefits of raw foods is an increased amount of fiber. In certain situations, when the body has become sick and toxic, raw foods may be better able to scrub the intestines, deliver enzymes, and help restore a functional intestinal wall.
A health center where I lectured once in Palm Beach, Florida, called Hippocrates, is a phenomenal cleansing center. It is based on Dr. Ann Wigmore’s raw food approach to restoring health. The question is, once you are cleansed, is a raw food diet sustainable? How about, say, in Vermont in January?
The theory that cooking can reduce the amount of nutrients like vitamin C has been studied. In tomatoes, the amount of vitamin C decreased by 10% when the tomatoes were cooked for 2 minutes, and by a whopping 29% when cooked for 30 minutes. No doubt, a case can be made that raw food may deliver more nutrients and health benefits, but even this notion is challenged.
When addressing certain serious illnesses, like cancer, both cooked and raw veggies had a beneficial effect. In one report, 28 studies were evaluated that compared the effect of a raw vs. cooked food diet on certain types of cancers. Both raw and cooked food had an inverse relationship with most cancers; meaning the more vegetables you ate, whether raw or cooked, most cancers went down. Different cancers responded uniquely to the raw or cooked diet, but it seemed that a plant-based diet was the key.
Ayurveda and Raw vs. Cooked Foods
Ayurveda is famous for its cooked food rule, but you could say this is more of a seasonal guideline than a rule. First, the major reason why cooked foods are preferred in Ayurveda is not because of nutritional content alone, as we contend in the West.
Cooked foods are much more kind and gentle to the intestinal wall. Raw food, being much higher in indigestible fiber, may offer cleansing benefits, but Ayurvedic practitioners set their sights on the health, function, and the integrity of the intestinal skin. The intestinal skin cannot be too dry, too wet, irritated, or mucousy–it has to be just right (think the three little bears). When the intestinal skin is balanced, beneficial microbes proliferate and the lymph that drains the intestines will function optimally to deliver nutrients and remove toxic substances. Cooked foods, but ones that have not been damaged by high heat and over-cooking, are easier to digest and more gentle to the intestinal skin.
In cases of inflammatory bowel conditions, the very first dietary recommendation that is made, almost by default, is to stop eating raw food. While raw foods are very cleansing, they are rough on the intestinal wall. A cleansing diet is not a sustainable diet.
Research suggests that the environment of the intestines and the microbes change with each season, supporting the more efficient digestion of seasonal foods. Microbes that can digest denser, higher-fat, higher-protein foods flourish in the winter along with greater microbial diversity for a stronger and more diverse immune response. In the summer, a less diverse set of microbes flourish to help break down more starchy and cellulose-rich foods.
This research suggests that your microbiome shifs from season to season, and that raw fruits and veggies would be more appropriate in the summer rather than in the winter. That said, Ayurveda still contends that slowly cooked foods at lower temperatures are most beneficial for the body’s ability to maintain optimal health. So, eat more cooked foods in the winter and, depending on your constitution and digestive strength, raw foods are fine in the summer.
Here are 10 basic veggie-eating rules to follow:
- Eat more cooked veggies and root veggies in the winter.
- Cook them longer and slower in the winter.
- Enjoy more raw fruits and easier-to-digest veggies like salads, celery, and cucumber in the summer.
- Steam veggies in the summer to break down cellulose.
- When cooking veggies, use the Color Power Test: During cooking, when the vegetable color becomes bright and vivid, the vegetable is done.
- Don’t soak vegetables in water, as nutrients will dissolve and drain.
- Steaming is best, as there is little contact with water.
- The higher the heat, the less contact between the vegetable and the water should be allowed.
- The lower the heat, the more contact with the vegetable and water should be allowed.
- Tender, not soft, is the goal–unless cooked in a soup or stew where all of the nutrients are captured.
The reality is that both raw and cooked foods can deliver the nutrients we need, but that is not the most important part of our health. The key is to eat veggies in season.
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