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Green smoothies are all the rage these days. Many people are drinking them every day or at least several times a week in an attempt to get healthy and “alkalize” the body.
Whenever I visit the cafe of my local healthfood store, there are usually several people in gym clothes lined up to order a green smoothie to sip after their workout.
Green smoothies are made by blending large amounts of raw leafy green vegetables with fruit to soften and sweeten the taste. Typical vegetables included in green smoothies are cruciferous vegetables like kale, broccoli, collard greens, maca (usually as a supplemental powder) as well as others like spinach, swiss chard, celery, and parsley.
Is the green smoothie fad a truly healthy habit over the long term? Or, could regular consumption of these seemingly healthy drinks contribute to serious health problems over time?
Raw Leafy Greens Contain High Oxalate Levels
Frequent consumption of large quantities of raw, leafy green vegetables blended up as green smoothies can be deceiving at first. This is because green drinks facilitate an initial detoxification process that makes a person feel great. This is especially true when coming off a highly processed, nutrient poor diet.
While very nutritious, the vegetables used in green smoothies are almost without exception high oxalate foods. Over time, a high oxalate diet can contribute to some very serious health problems particularly if you are one of the 20% of people (1 in 5) that have a genetic tendency to produce oxalates or if you suffer from candida or other fungal challenge. In those cases, a high oxalate diet can deal a devastating blow to health.
Oxalate Toxicity Not a New Problem
The effects of oxalate toxicity have plagued humankind since ancient times. For example, scientists discovered an oxalate kidney stone about the size of a golf ball in a 2000 year old mummy from Chile using x-ray analysis.
Build-up of shards of oxalate crystals can occur almost anywhere in the body. Whatever tissue contains them, pain or worse is the result.
75-90% of kidney stones are oxalate related with 10-15% of Americans afflicted at some point during their lives. As the star shaped crystalline stones pass from the kidney, they cause pressure and pain in the bladder and urethra and can actually tear up the walls of the urinary tract.
Oxalate Stones from Excessive Green Smoothies
Oxalate stones can show up in any body tissue including the brain and even the heart.
Crystals comprised of oxalates resemble shards of glass. They can become lodged in the heart causing tiny tears and damage to this vital muscle. With every single contraction, more damage is caused as the heart pumps life giving blood to the rest of the body.
Oxalate crystals which end up in the thyroid can cause thyroid disease by damaging thyroid tissue.
A frequent location for oxalates to end up is skeletal muscle which will cause pain with even normal movement and make exercise nearly impossible. Dr. William Shaw, Director of The Great Plains Laboratory for Health, Nutrition and Metabolism who has studied oxalates extensively, is convinced that oxalate toxicity is a factor in fibromyalgia the pain of which can absolutely devastate a person’s life (1).
Vulvodynia – Painful Sex
Cases of women experiencing painful sex are on the rise with oxalates a possible culprit.
Vulvodynia is a condition causing pain in and around the vagina. It is linked to oxalates deposited in this delicate reproductive tissue. Oxalate crystals are very acidic and they cause irritation, burning, and stinging sensations for affected women. An accompanying feeling of rawness is typically experienced during sexual relations.
Oxalates Are Fungal in Origin
A surprising finding is that oxalates are produced in large amounts by fungus. Large stones have been found in the sinuses and lungs of people suffering from systemic fungal infections such as candida or Aspergillus.
Therefore, anyone who suffers from any sort of candida overgrowth or other fungal challenge like fungus nails or dandruff would be wise to be very concerned about oxalate intake via the diet.
Consumption of green smoothies would not in any way contribute to improvement of health in these situations. The majority of people today suffer from gut imbalance and candida (yeast) issues caused by antibiotic and prescription drug use including the Pill. This renders a high oxalate diet which includes frequent green smoothies an unwise practice for virtually everyone.
Does Cooking Destroy Oxalates?
What about cooking the greens first? Would this reduce the risk of oxalate overload and make consuming greens safer?
Not really, because oxalates are extremely stable. While cooking high oxalate foods and discarding the cooking water does reduce the level of anti-nutrients, it remains quite high.
Green smoothies are usually consumed frequently by those who swear by them. As such, a light steaming of the veggies first would not make a significant difference over the long term if they are consumed regularly. If you consume green smoothies only occasionally, however, a light steaming is a good idea. This practice adds a degree of safety to the process. Other tips for preparing safe smoothies are contained in this linked article.
Healthier Alternatives to Green Smoothies
The best course of action for health, then, is to opt out of the green smoothie diet fad. This is especially important if you have any sort of gut imbalance or candida issues.
If you enjoy green leafy vegetables, be smart about it. Don’t overdo like so many in the health community are doing with the best of intentions. Enjoy green drinks in moderation in salads. Or, cook them and carefully drain and discard leafy green cooking water. Never use it in soups and sauces!
Be sure to serve cooked leafy greens with a healthy fats like butter or coconut oil. Avoid margarine or any factory fats synthesized with rancid and/or GMO vegetable oils like Smart Balance. Using natural fats will facilitate maximum absorption of minerals.
Another option is to drink raw cultured vegetable juice or eat raw cultured vegetables. Not only will you get enhanced nutrition from the culturing process which adds enzymes and nutrients, but you will also get a beneficial and therapeutic dose of probiotics to help balance gut function and improve digestion. It also suppresses fungal overgrowth like candida.
Wheatgrass an Excellent Alternative!
Another option is to do shots of fresh, green wheatgrass juice.
Wheatgrass juice is very low in oxalic acid.
Here is a link to my favorite green juice recipe using wheatgrass and ginger. It is safe to drink regularly, daily if you like, instead of green smoothies. It is also an excellent drink for gently detoxing before pregnancy. The ginger assists with morning sickness issues too if you are already pregnant.
What to do if a Green Smoothie Diet Has Already Harmed Your Health
Are you already are suffering from some of the ailments described in this article? Do you suspect a high oxalate diet which includes green smoothies or a daily spinach salad may be the cause? If so, stop this practice immediately and consult with a holistic physician. You will likely need professional assistance to guide you on the road to recovery. Ridding your body of oxalate crystals that are potentially irritating one or more of your body tissues is no simple task! It is not advisable to attempt this protocol on your own.
Sarah, The Healthy Home Economist, author, Get Your FATS Straight
References and Additional Information
The Role of Oxalates in Autism and Chronic Disorders, William Shaw PhD
Top 4 Cleansing Myths to Watch Out For
A lot of people commenting need to learn a little bit about veggies and fats! We have some fat-ophobics on here, which is surprising. Fats are good for you, and they make your veggies healthier! There’s a reason why veggies taste way better in butter…
I think everything in moderation is important. However, if I skip on greens I’m a pretty cranky person. I don’t consume tremendous amounts, but I would say we through about 4-6 heads of kale a week, between my husband and myself. I would take more issue with the overuse of sweet fruits in those smoothies as it can feed candida.
A friend just pointed me to this article: http://www.incrediblesmoothies.com/green-smoothies/oxalates-spinach-oxalic-acid-health-concern/ It is put out by a smoothie blog, so it make sense they are pro-green smoothies. I just wish that health experts could agree on something. I do appreciate you weighing in on tough health topics though! In the end I the best any lay person can do is read as much as possible and figure out what works for our own bodies. Which after reading Real Food Blogs for 2 years now, I am still at a loss.
For claiming somewhere in that or another oxalic acid/oxalate post that her article is “well researched”, I beg to differ…even if it was there is _no_ proof and _no_ footnotes behind what she says.
so interesting. we always heard good things about green smoothies…
Here is a good link regarding oxalates. Like anything else, it comes down to bio-individuality.
Use common sense people.
http://www.uwhealth.org/urology/oxalate/11252
I have to disagree…I JUST passed a 5mil kidney stone this month….I have never had one in my life….in the past 6 months I have started drinking a green smoothie for breakfast…..when I brought the stone to my Urologist I questioned her about my oxalate stone and how it related to the green smoothies…should I continue drinking them etc. The answer she gave was this: You would have to eat many POUNDS of spinach, kale etc each day to have a stone form. She told me that people that drink soda, especially “brown colored” soda are at a much HIGHER risk of forming oxalate stones than green smoothie drinkers. Her advice: Drink green smoothies! DO NOT DRINK ANY SODA!
Totally agreed! Thank you..
It seems to me that if you’ve never had stones before but developed them AFTER starting a regimen of daily leafy green smoothies that the proof is in the pudding. I know no one wants to admit this, but Doctors are not always right…in fact, they are frequently DEAD WRONG, especially when it comes to knowledge about nutrition. Think about how often and how drastically the recommendations for food consumption have changed over the years. I have stopped listening to Doctors and have started doing research. The Weston Price Foundation, while not perfect, is a good start. AND their recommendations are based on anecdotal evidence combined with many, many years of research.
here here! If the two leading cause of deaths are heart disease and cancer – Doctors are The Third Leading Cause of Deaths.
Shelley, a doctor told my Dad that taking radiation was a good idea to stop his cancer. He died at 58 from prostate ca met to the bone. We now know that radiation can spread cancers and that it eats away at the bones and other tissue, which I saw with my own eyes. Not all doctors know everything. Wish I had my Dad back and hadn’t believed a doctor.
I wonder what you would say to The Gerson Therapy method with over 75 years of successful, documented cancer treatments using green juices? Check out http://www.Gerson.org
I am beyond confused and dismayed by this article. Sarah, I appreciate your blog and passion, and am wondering about your credentials. Are you a dietician or naturopath or something? Please help me understand from where you get your information.
Thank you.
I think using green juices therapeutically is a great idea, and really works, but not beyond that. I myself do a 3 day green smoothie fast every spring, using mostly parsley, watercress and cucumbers with some fruits.
Gerson therapy does allow some greens like beet tops, but no spiniach unless it is cooked. I think people see a large improvement on green smoothies because there is a lot of good nutrition in them and they are such a vast improvement above what most people are eating. People’s argument of “well I feel phenomenal while I drink them” is not really a great point. People usually feel great when they start a vegetarian diet because they are detoxing from so many SAD foods. I think they could be a great idea for people to do as a cleanse or health booster for a time, but the possible long-term negative effects are something that people should be aware of. There are obviously a few people posting on here who did recover from oxalate overload when they stopped drinking them.
People need to quit being so extreme. Just because Sarah educated us about some facts and said she personally avoids them people are attacking her! (I realize you aren’t being rude, Marise, but some people are going crazy!)
The point of the article is that green smoothies are a fad and consuming raw leafy greens in the enormous quantities that people are consuming them in green smoothies is a recipe for health disaster due to the oxalate problem that is caused especially since people with candida issues already likely have an oxalate problem as fungus creates oxalates in the body so watching the amount of oxalates in the diet becomes even more important.
I find this article informative, but one-sided. Leafy greens are rich in folate and about 45 % of the population is a carrier for the MTHFR polymorphism. It’s reported 99 % of people on the autism spectrum disorder have this polymorphism. Carriers have have several issues and one is the need for naturally occurring folate, and leafy greens are rich in this. Lack of folate ( not synthetic folic acid, this is very bad for carriers ) plays a role in miscarriage. And addressing the WAPF way of living, Dr. Price specifically believed a lack of phosphorus and calcium were a direct contribution to tooth decay and leafy greens provide a perfect ratio of this. I’m not skipping out on my green smoothies or greens.
You are full of bull!!! Jack Lalanne juiced his entire life and died and a ripe OLD age of 92. He was generally in good health his entire life. You are nothing more than an alarmist and you offer no scientific proof of your claim. Our own bodies actually produce oxalates by themselves without any help from juiced leafy green vegetables.
Follow-up to previous post.
Oxalates are naturally-occurring substances found in plants, animals, and in humans. In chemical terms, oxalates belong to a group of molecules called organic acids, and are routinely made by plants, animals, and humans. Our bodies always contain oxalates, and our cells routinely convert other substances into oxalates. For example, vitamin C is one of the substances that our cells routinely convert into oxalates. In addition to the oxalates that are made inside of our body, oxalates can arrive at our body from the outside, from certain foods that contain them.
Foods that contain oxalates
The following are some examples of the most common sources of oxalates, arranged by food group. It is important to note that the leaves of a plant almost always contain higher oxalate levels than the roots, stems, and stalks.
Fruits
blackberries, blueberries, raspberries, strawberries, currants, kiwifruit, concord (purple) grapes, figs, tangerines, and plums
Vegetables (see Table 1 for additional information)
spinach, Swiss chard, beet greens, collards, okra, parsley, leeks and quinoa are among the most oxalate-dense vegetables
celery, green beans, rutabagas, and summer squash would be considered moderately dense in oxalates
Nuts and seeds
almonds, cashews, and peanuts
Legumes
soybeans, tofu and other soy products
Grains
wheat bran, wheat germ, quinoa (a vegetable often used like a grain)
Other
cocoa, chocolate, and black tea
Oxalates and health
Conditions that require strict oxalate restriction
There are a few, relatively rare health conditions that require strict oxalate restriction. These conditions include absorptive hypercalciuria type II, enteric hyperoxaluria, and primary hyperoxaluria. Dietary oxalates are usually restricted to 50 milligrams per day under these circumstances. (Please note: these relatively rare health conditions are different than a more common condition called nephrolithiasis in which kidney stones are formed, 80% from calcium and oxalate). What does 50 milligrams of oxalate look like in terms of food? One cup of raw spinach in leaf form (not chopped) weighs about one ounce, and contains about 200 milligrams of oxalate, so 50 milligrams for the day would permit a person to consume only 1/4 cup of raw spinach (and no other oxalate sources could be eaten during the day).
Oxalates and kidney stones
The formation of kidney stones containing oxalate is an area of controversy in clinical nutrition with respect to dietary restriction of oxalate. About 80% of kidney stones formed by adults in the U.S. are calcium oxalate stones. It is not clear from the research, however, that restriction of dietary oxalate helps prevent formation of calcium oxalate stones in individuals who have previously formed such stones. Since intake of dietary oxalate accounts for only 10-15% of the oxalate that is found in the urine of individuals who form calcium oxalate stones, many researchers believe that dietary restriction cannot significantly reduce risk of stone formation.
In addition to the above observation, recent research studies have shown that intake of protein, calcium, and water influence calcium oxalate affect stone formation as much as, or more than intake of oxalate. Finally, some foods that have traditionally been assumed to increase stone formation because of their oxalate content (like black tea) actually appear in more recent research to have a preventive effect. For all of the above reasons, when healthcare providers recommend restriction of dietary oxalates to prevent calcium oxalate stone formation in individuals who have previously formed stones, they often suggest “limiting” or “reducing” oxalate intake rather than setting a specific milligram amount that should not be exceeded. “Reduce as much as can be tolerated” is another way that recommendations are often stated.
The effect of cooking on oxalates
Cooking has a relatively small impact on the oxalate content of foods. Repeated food chemistry studies have shown no statistically significant lowering of oxalate content following the blanching or boiling of green leafy vegetables. A lowering of oxalate content by about 5-15% is the most you should expect when cooking a high-oxalate food. It does not make sense to overcook oxalate-containing foods in order to reduce their oxalate content. Because many vitamins and minerals are lost from overcooking more quickly than are oxalates, the overcooking of foods (particularly vegetables) will simply result in a far less nutritious diet that is minimally lower in oxalates.
Practical tips
For the vast majority of individuals who have not experienced the specific problems described above, oxalate-containing foods should not be a health concern. Under most circumstances, high oxalate foods like spinach can be eaten raw or cooked and incorporated into a weekly or daily meal plan as both baby spinach and mature, large leaf spinach can both make healthy additions to most meal plans. In short, the decision about raw versus cooked or baby versus mature leaf spinach or other oxalate-containing vegetables, for example, should be a matter of personal taste and preference for most individuals.
Table 1
Raw Vegetable Oxalate contentmilligrams per 100 gram serving
Spinach 750
Beet greens 610
Okra 146
Parsley 100
Leeks 89
Collard greens 74
Adapted from the following sources: (1) United States Department of Agriculture, Human Nutrition Information Service, Agriculture Handbook Number 8-11, “Composition of Foods: Vegetables and Vegetable Products.” Revised August 1984; (2) data gathered by LithoLink Corporation, a metabolic testing and disease management service for kidney stone patients, founded by Dr. Fredric Coe, a University of Chicago Medical School Professor, and posted on its website at http://www.litholink.com; (3)data presented by Holmes RP and Kennedy M. (2000). Estimation of the oxalate content of foods and daily oxalate intake. Kidney International(4):1662.
References
Assimos, D. G. and Holmes, R. P. Role of diet in the therapy of urolithiasis. Urol Clin North Am. 2000 May; 27(2):255-68.
Curhan, G. C. Epidemiologic evidence for the role of oxalate in idiopathic nephrolithiasis. J Endourol. 1999 Nov; 13(9):629-31.
Hanson, C. F.; Frankos, V. H., and Thompson, W. O. Bioavailability of oxalic acid from spinach, sugar beet fibre and a solution of sodium oxalate consumed by female volunteers. Food Chem Toxicol. 1989 Mar; 27(3):181-4.
Kelsay, J. L. and Prather, E. S. Mineral balances of human subjects consuming spinach in a low-fiber diet and in a diet containing fruits and vegetables. Am J Clin Nutr. 1983 Jul; 38(1):12-9.
Kikunaga, S.; Arimori, M., and Takahashi, M. The bioavailability of calcium in spinach and calcium-oxalate to calcium-deficient rats. J Nutr Sci Vitaminol(Tokyo). 1988 Apr; 34(2):195-207.
Parivar, F.; Low, R. K., and Stoller, M. L. The influence of diet on urinary stone disease. J Urol. 1996 Feb; 155(2):432-40
Prakash D, Nath P, and Pal M. (1993). Composition, variation of nutritional contents in leaves, seed protein, fat and fatty acid profile of chenopodium species. Journal of the Science of Food and Agriculture 62(2):203-205.
Sienera R. (2006). Oxalate contents of species of the Polygonaceae, Amaranthaceae and Chenopodiaceae families. Food Chemistry 98(2):220-224.
Oh Sean, THANK YOU!! That is quality information, not happenstance non-sense that this original post is chocked full of. I am highly surprised little Miss Know-It-All Sarah didnt verbally backhand you. 🙂 But i am sure she may try to as it seems she cant handle anyone “insulting” her with the truth.
Again? You sound hypocritical. You appear to be what you accuse Sarah of… an insulted know it all.
Actually, Tina I am not an economist turned nutrition nut like Sarah claims to be. I actually studied this stuff and have degrees in Nutrition and Food Science, Molecular Biology and a few other than correlate. this blog was brought to my attention through a friend and colleague. This type of blogging really needs to be shut down. this post is obviously driven by opinion not fact. She has one obscure source from which it is to be assumed she has conjured these conclusions. All I have asked is that she post rational valid proof of what she is claiming other wise it is just hearsay. None of what she has is hard evidence of anything. It is all circumstantial. I am not insulting her I am stating that she comes across and an expert and yet she has NO validation and her credentials are lacking. Economics is a far different science from biology and natural chemistry. You cant just decide , “Ah I bored and because I have a degree in something and I have passion for something else I am an expert.” But alas that is what the blogging universe has become, few actual true experts but a caboodle of yappers that think they know what they are talking about.
otherwise
I can’t sit by and let one of my favourite bloggers be verbally assaulted like this! What I would like to know is, why are you people, who not only so obviously do not agree with Sarah or WAPF principles but also seem quite rude, even reading this blog? If it’s only to insult Sarah, then shame on you! It’s a free country and she has the right to voice her opinion, particularly on HER OWN BLOG! This is Sarah’s blog. Go get your own blog!
I can’t stand this article and think she’s an idiot and I’m not subscribed to this blog. Someone shared it on FB and scared the crap out of other people not subscribed to her blog. Newsflash: there’s a thing called social media where stupid, inaccurate, LIES are shared and it’s harmful. I will NEVER subscribe to this, trust me! so that hopefully answers your question. This retarded article got put in people’s news feeds and we have the RIGHT (freedom of expression) to call it bull. 🙂
Prime, sure you have the right to call things what you want I guess, as this is a free country. But, if you’re not interested in this kind of thinking about health, why would you bother? I’m sure you have far more important things to attend to. You also don’t make any friends by spouting off like this. Since you agreed that we have the right to express ourselves as we see fit, then why not let Sarah express her opinion in peace? You think it’s bull, she thinks it’s valid. Since this is her blog, I think you must graciously concede.
Sean, just FYI. I would not bother to post all that info AFTER you begin with rudeness. I will not read it, and I suspect others feel the same. Wouldn’t it have been better to dialogue in a respectful manner with Sarah, than to join in the name-calling with CheryL? THINK.
You suspect that others will join you in sticking their heads in the sand knowing there is a through list of sources that disagree with something you want to believe because he said the author was “full of bull”?
There is a lot left out on the topic of “candida or other fungal challenges”. Antibiotics pave the way to a lot of that stuff. A good probiotic, or plain greek yogurt with a small drizzle of honey or pinch of blueberries every night can give those fungal challenges (as well as the prescriptions given for them) a run for their money.
*thorough.
Jack Lalanne probably didn’t have a candida or fungal issue. Some figures show that as many as 80% of Americans probably have candida issues.
Try not to be so abrasive! It’s fine to disagree but the majority of people on here are acting like they’ve been attacked personally.
Ahhhhh here we go again….dont you sound like a hypocrite! How can you accuse Sarah of sounding like a know it all when thats exactly how you sound? And honestly…please do not comment on this blog if you do not agree with at least some of the Weston A Price philosophies or if you’re not willing to present your opinion tactfully without being rude. And no disrespect…but you having degrees doesnt say much about you either. Those are just things that you were taught by “the man”. Its just like religion and science. There are 2 sides to everything. In this case its the old way of doing things and the new way.
You underestimate the damage and roadblocks that misinformation can spread when something somehow makes it’s way to the top of the search results despite being based on one or two questionable sources. It might seem trivial, but you never know how many people might’ve been steered away from something that could make a world of difference in their life because they get this article stuck in their head and don’t go through the comments.
I am not a vegan, I am not a vegetarian, I am not a paleo diet commando, and I eat meats, coconut oil, and the greens too. My bias, my “agenda” here, is having to explain to my elders after they linked me this article, to please research beyond this blog post, and I’m not the only one who came here in this boat.