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Conventional belief is that raw vegetables are always healthier than cooked, but this is not true depending on the plant foods eaten according to lab testing and anthropological evidence by experts in the field.
I stopped by one of my favorite healthfood stores today to pick up a large glass of fresh juice made from organic raw vegetables for an early lunch on the go. As usual, I asked for the a carrot, celery, beet, spinach and cucumber blend. But, hold the spinach. I definitely skipped the green smoothie too!
While this request is usually met with a simple nod by the juice bar attendant, this time the guy looks up and says, “Why no spinach? We have a lot of people that come in here and love the spinach in their juice.”
Ah! Great question!
The truth is that not everything should be eaten raw, especially vegetables!
Some raw vegetables must be cooked else you are actually harming yourself. Below is a rundown of what veggies should not be eaten raw either in whole or juiced form.
Cruciferous Raw Vegetables
Sorry to be the bearer of bad news, but cruciferous vegetables should be cooked before eating as they contain chemicals that BLOCK the production of thyroid hormone in your body! Considering that 2 out of every 3 Westerners are either overweight or obese and this is projected to jump to 75% by 2020, this is of particular importance as folks struggling with weight usually suffer from borderline to full-blown hypothyroidism.
Hypothyroidism is a condition where the thyroid gland does not make enough thyroid hormone, so someone suffering from this condition surely does not want to be eating foods that will block what little thyroid hormone is being produced in the first place!
Symptoms of hypothyroidism include cold hands and feet, thinning hair, fatigue, reduced or nonexistent libido, coarse dry hair, constipation, difficulty losing weight, and depression among many others.
Cooking crucifers reduces the goitrogenic substances by about 2/3. Fermentation does not reduce goitrogens in these veggies, but since fermented crucifers such as sauerkraut are typically eaten as a condiment and, hence, in small amounts, consumption is fine if the diet is rich in iodine.
Here is the list of common cruciferous vegetables that you do not want to be eating raw if you want to protect your thyroid gland!
Arugula, broccoli, kale, maca root, cauliflower, cabbage, turnip, collard greens, bok choy, brussels sprouts, radish, rutabaga, and watercress.
Notice that many of these vegetables are commonly included in fresh veggie juice blends or in salads. While an occasional arugula salad or cup of coleslaw is not going to do harm to most folks, it would be wise not to make a habit of eating/drinking any of these vegetables in raw form. Kale chips are a safe choice too.
Raw Vegetable Greens
Some veggie greens contain a chemical called oxalic acid. This substance is a very irritating to the mouth and intestinal tract. It also blocks iron and calcium absorption and may contribute to the formation of kidney stones.
The good news is that oxalic acid is reduced by a light steaming or cooking. Just be sure to discard the vegetable cooking water.
Veggies containing oxalic acid include spinach, chard, parsley, chives, purslane and beet greens.
Hmmmm. Spinach is known for being high in iron, yet eating it raw will not necessarily give you the iron you want because of the oxalic acid?
Yep, that’s right. Cook that spinach first if you are seeking an iron boost without the indigestion and don’t get hooked on the raw spinach salads!
Don’t stress about munching the parsley garnish on your next gourmet dinner, though. A little bit here and there is not going to cause a problem. Eat a big spinach salad everyday and it is virtually certain you will eventually succumb to kidney stones, according to Dr. William Shaw, Director of The Great Plains Laboratory for Health, Nutrition and Metabolism.
Other Raw Vegetable Cautions
Other vegetables that are best to avoid eating raw include:
- Raw potatoes contain hemagglutinins that disrupt red blood cell function.
- Raw sweet potatoes will give you gas.
- Raw, edible mushrooms such as the common white mushroom contain toxic substances such as agaritine, a suspected carcinogen. These substances are heat sensitive and are neutralized by cooking.
- Raw alfalfa sprouts are mildly toxic and inhibit the immune system. Eating large quantities regularly can make the skin overly sensitive to the sun or trigger autoimmune symptoms that mimic lupus.
Dr. Weston A. Price on Raw Vegetables
A good rule of thumb when considering the best way to consume your veggies is to remember the letter that Dr. Weston A. Price wrote to his nieces and nephews in 1934. In this letter, he strongly urged them to eat their vegetables cooked in butter. His research found that the bulkiness (fiber) of raw vegetables interfered with the human body’s ability to extract minerals from them via the digestive process.
So, should you drink your veggies raw? Of course. Raw vegetable juice made from veggies that are safe to consume uncooked is a wonderful way to get a fast infusion of easy to digest, colloidal minerals. It is also highly alkalizing to the body and a proven way to gently detox the gut.
The great thing about veggie juice is that the fiber is removed, which is the “bulkiness” that Dr. Price found interfered with the mineral absorption.
However, if you are going to eat the fibrous portion of the vegetable, it is best to cook them in butter as advised by Dr. Price to enhance the availability of the minerals. The fat in the butter permits greater absorption of the minerals, and besides, buttered veggies taste fantastic!
References
Nourishing Traditions
The Role of Oxalates in Chronic Disease, William Shaw PhD (Director of The Great Plains Laboratory for Health, Nutrition and Metabolism)
More Information
Best Green Juice for Congestion
Nightshade Vegetable Contraindications
Cleansing Myths
You lost me after “Raw Foodies, I love you, I REALLY REALLY DO (but, PLEASE eat some meat! You’re looking a wee bit pale).”.
Research backs up Dr. Price on fibrous foods interfering with mineral absorption.
http://www.ajcn.org/content/72/2/466.full
If you think about it, one of the selling points the “plant-based diet” advocates have come up with for eating a diet higher in fiber is that the fiber moves matter through the GI tract *more quickly.* Stands to reason, then, that if you eat food high in fiber, your body will not have enough time to absorb all the nutrients it could possibly absorb from that food matter. And that is not even getting into the fact that so many “plant-based diet” advocates are also low-fat advocates and they depend too heavily on plant foods for their fat-soluble vitamins–this despite increasing evidence that human beings are poor converters, at best, of fat-soluble vitamin precursors found in plants.
So. Fiber’s moving the food too fast, usually there’s not enough fat there to help with mineral absorption either, and on top of that they’re probably short on the fat-solubles (definitely short on vitamins A and K2)–and you’ve got a recipe for disaster. Not just hypothyroidism but also diabetes (at least two mineral deficiencies seem to be associated with the disorder, chromium and magnesium) and osteoporosis.
On top of that the fiber causes faster cell turnover, which is also acknowledged by high-fiber-diet advocates. They say it prevents colon cancer. But where are we most likely to find cancers in the body? Any place there’s a high rate of cell turnover, that’s where.
Food for thought. (No pun intended.)
http://t.co/TX8Kzpi
“Good” vs. “Bad” foods: one person says this food is the healthiest thing in the world, the next claims it is a toxic poison. Seems a LOT of people here are “offended” by this article – either they believe All veggies should ONLY be consumed raw, or they believe that Oxalic veggies are deadly to “everyone.” Sorry, the Raw Foodies lose the argument with statements that claim ALL cooked foods will kill you (the Human specieas would have died out long ago). Now, the Oxalic-Sensitive people do have a point, but I do NOT think that this entire post must be re-written. However, perhaps a *Disclaimer* should be included that states that some people ARE Oxalic-sensitive and that they must avoid such foods altogether as cooking will not remove all the Oxalates. Commenting that this advice is bad for “ALL” people and Oxalic Acid should “never” be consumed by “anyone” is absurd! That’s like a Celiac chiming in on a whole grain recipe and claiming that it should be re-written because “Everyone can / will be negatively affected by gluten.”
This article is accurate, in my opinion. I TRULY believe that you should primarily consume a diet based on the traditional diet of your ancestors – that’s why I CAN eat tons of crucifers and have no problems – Eastern and Northern Europeans have been doing this for eons!
This article is good general advice for HEALTHY people!
While there may be oxalic acid in crucifers (I haven’t looked that up), if you actually *read* the above article you will see that the HHE classifies crucifers and high-oxalate vegetables into two different categories, not the same one.
You may or may not wish to take note, also, that good health as relates to diet appears to arise from two different behaviors: one, avoiding foods that cause disease but also two, eating foods that encourage good health. Not all of the ancestors followed ideal diets–we could not have figured out which foods were healthy if no one ever chose the wrong foods!–but of those who did, clearly some of them ate foods that cause or contribute to health problems in our population today. There are people who react badly to wheat, for instance, and yet ancestral populations could eat wheat. What’s the difference? Well, we could talk about new strains of wheat and this toxin and that personal habit, but at the end of the day, look at Dr. Price’s numbers. Ancestral people who followed healthy diets got so many times more the animal fats and the minerals and the fat-soluble vitamins compared to Americans *of Price’s day* and it’s even worse now. There are people now who *never eat a food with vitamin A in it.* There are people who never touch the foods he considered most important, and yet they still eat the foods that we know to cause or contribute to health problems.
Do you think there might be a connection there? I sure do. If you’re eating more than enough of the demonstrably healthy foods, you have more wiggle room to eat the foods that perhaps are less healthy. Probably why people could get away with eating sugar in the early part of the 20th without so much obesity and diabetes. They were still getting lard and tallow and butter and milk and liver at home!
That said, there’s an easy rule of thumb for when people should be more careful of cruciferous veggies at least: If they taste bitter to you, eat fewer of them. Scientists have found a link between people finding broccoli bitter, and people whose thyroids are slowed down by it. Apparently their ancestors lived far from the sea and, therefore, far from reliable sources of iodine.
That said, even someone with coastal ancestors could possibly take it too far. We have a high population of people in the United States with Irish ancestry. Broccoli derives from a Gaelic word. The Irish clearly have had long experience with this vegetable so why is the rate of hypothyroidism so high?
Scratch that about broccoli coming from Gaelic and I’m embarrassed now. It actually comes from Italian, but the Irish adopted the word into their language. That said, Italy is largely coastal too, and we also have a high Italian population here. No idea how they experience hypothyroidism compared to the rest of us but quite a few of them *do* become overweight and have other hormonal issues. So… there you go.
Hmm, I’ve been reading though all the comments (LOTS ;)) and began thinking about something regarding RAW Oxalic Acid being good, and about consuming LOTS of fermented sauerkraut (cabbage).
I’m including the entire oxalic acid quote below for reference.
Upon first reading I thought to myself ‘Hey! Good point! Schav is a VERY Oxalic Sorrel soup! And it is a VERY TRADITIONAL Eastern European staple food!’ Schav is a cold (usually) soup made by boiling cultivated garden Sorrel (not Sheep or Wood Sorrel) in a pot of water. This is allowed to cool and it is poured into bowls and into the soup is added a chopped up hard-boiled egg and a dollop of sour cream. It is served with a boiled potato with either butter or sour cream on the side (personally I chop the potato into the Schav). This is how it is eaten. ALWAYS! Usually the sour cream content is so high that it is more like a cream soup. The Sorrel soup alone is SO SOUR you cannot possibly consume it alone.
So, anyway, at first I thought – HEY! You do NOT discard the water from Schav – if you did you would not have any Schav! And, since they’ve been eating this forever in the summer months, then it can’t be all that bad, right? So, it must be that the added calcium from the sour cream is what makes it edible! And maybe the added protein and fat from the egg as well.
So, you see, at first I though Dr. Walker’s argument made sense. BUT, in fact, if you think about it, the key is that the Sorrel is COOKED! So, even though you are consuming the Oxalic Acid water, it has been cooked AND in combination with the DAIRY and EGG, perhaps it IS ok for humans to consume. Now, this sounds to me like a valid hypothesis worthy of further investigation!
As for consuming LOTS of sauerkraut, specifically kimchi, I must admit that I consume a LOT of sauerkraut – just like ALL Germans and Poles – but, it is actually FRIED with pork chops or a Wurst (as a Vegetarian I replace the meat with carrots – NO TOFU / Soy EVER!). So, if you really LOVE sauerkraut then you can consume all you want if you fry it up in fat! YUMM!!!
Quote:
Anonymous October 15, 2010 at 9:51 pm
“Organic oxalic acid, defined as that which occurs in nature in its raw form, can actually be beneficial to the system. Once foods containing oxalic acid are cooked, according to the dean of juice therapy and author of Raw Vegetable Juices, Dr. Norman Walker, the oxalic acid becomes dead and irritating substance to the system. He feels that in its cooked form it binds irreversibly with the calcium and prevents calcium absorption. An excess of cooked oxalic acid may also form oxalic acid crystals in the kidney. In the live organic form of oxalic acid, Dr. Walker claims oxalic acid stones and calcium blockage do not occur because the organic oxalic acid can be metabolized appropriately. according to Dr. Walker, oxalic acid in its raw form is one of the important minerals needed to maintain tone and peristalsis of the bowel.”
Christi,
You can still eat these greens to get your fiber – just cook them first. Cooking does not eliminate the fiber content! In fact, fiber is meant to be CHEWED! I do not understand why people think you can “drink” your fiber?!? I also hate that suddenly “fiber” has been added to the oddest foods nowadays – my mother recently purchased Polaner Jam (no HFCS) and it had “added fiber” – Oh my, it was VILE! The texture was like Jello (YUCK) overloaded with cornstarch grains! Umm, am I crazy or does “whole fruit” jam / preserves not already have plenty natural fiber in it to begin with?
Just eat lots of fresh fruits and veggies, and even cooked and you should be fine. And you can still eat non-grains like Quinoa. Oh yeah, don’t forget to drink PLENTY OF WATER! That should help with any constipation problems! And avoid SUGAR, especially sodas and drinks with added sugar (and avoid all NON-cane /honey / maple syrup /Stevia “sweeteners” all together) – too much added sugar will cause constipation – humans cannot digest Fructose, so avoid High Fructose Corn Syrup and AGAVE at ALL COSTS!
I have to cook Purslane and Chives?!?! YIKES!
Hmm, Sorrel (cultivated) contains HIGH levels of Oxalic Acid – my mother tried to convince me to eat a “Sorrel Salad” the other day – NO WAY! I could barely consume one entire raw leaf! That’s what Schav is for! But chives and Purslane? Purslane is a bit bitter, but more “spicey” in my opinion, and chives are not bitter at all. I just “harvested” a whole bunch of taller (~12″h) larger leaved purslane from a crab-grass weed patch that I was tilling – it was SO JUICY and yummy RAW! The normal creeping small-leaved variety is less juicy and a bit more bitter.
Well, to add to the Oxalic Acid list there is Wood Sorrel – it looks like Clover, but the leaves are heart-shaped (Shamrocks are actually Wood Sorrel) and it has yellow flowers – it is a common “weed” but totally edible (the entire plant) – I went harvesting White Clover and accidentally picked Wood Sorrel instead – it tastes like a cross between lemons and crab apples! I ate some in my “Wild Salad” the other day (the heat killed off all my cultivated lettuce, so I went wild “weed” harvesting); it was good with a simple dressing of EVOO and Apple Cider Vinegar and just some salt and pepper.
As for the White Clover, I tried one leaf – it is a very short plant, so difficult to harvest, but the entire plant is edible (including roots). I don’t know if it has to be cooked, but the one leaf was quite tough and tasted like spinach. I’ll probably try sauteeing some in butter this weekend. The fresh flowers are edible, but apparently once they turn brown they become poisonous. Red Clover (purple flowers) supposedly tastes better, but my garden has yet to be graced by that “weed” or Chickory or Burdock, for that matter 🙁
What about Common Plantain (Plantago Major)? Not the banana – the weed that grows in grass, almost like a dandelion – does that need to be cooked? I know you can use the fresh juice to cure a whole host of ills, but what about consuming it on a regular basis as a veggie? Should it be cooked? I dug up a whole bunch from a gravel parking lot and planted them in a pot – I won’t actually eat those until new leaves form next year though. And Lamb’s Quarters? I think that is supposed to be cooked, but it just makes such a yummy salad!
Ah, well, I guess I’ll have to start making a lot more omlettes with all these veggies that must be steamed / sauteed first. 😉
Actually, that is a good question: Do you have to actually steam and dump the water first, or is simply sauteeing the fresh veggies in butter enough?
Great blog, btw: it is a fun, short and sweet take on W.A.P / Traditional / Whole Foods diets!
If the greens are lightly steamed (like kale) can they safely be juiced?
Part of the trouble seems to me that these days nobody learns to cook anymore. Instead people fall victim to all sorts of nutritional fads, especially those promising eternal life, a life free from cancer etc. Man discovered cooking and preparing his food early on – and then made some progress. We are not designed to live on raw food – our digestive system is not up to it. Most of the nutrients are absorbed in the small gut so we need energy-dense food to nourish us. Plant eaters have a large colon (as opposed to ours) where they can absorb nutrients from raw stuff and from roughage. We cannot – once the food it out of our small gut, almost no more nutrients will be absorbed. Eating too much fibre can damage the very sensitive gut tissues and lead to a number of problems.