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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
Why would eating greens in a salad from time to time be better than eating them in a smoothie from time to time? Seems to me that you’re really saying that high levels of oxalates are bad for your health. But, I do suppose the controversial title will get you a lot more hits than entitling it what you’re really trying to say.
Sarah, don’t let these negative comments get you down! I love your blog and always learn so much! Please don’t get discouraged because people are too thick-headed to think for themselves. Keep sounding the alarm and proclaiming the truth. They ignore it to their own detriment.
Sarah, thanks so much for this post! I’m so glad to see more nutrition bloggers raising their audience’s awareness of oxalates, and all the negative ways in which they can affect people’s health when consumed in excess.
I’m a bit bummed to see some of the incredibly negative, and incredibly defensive reactions to this. However, I figure in the long run it’s still a good thing. If someone has a negative reaction to a post, they will hopefully remember it. So years down the line, when they’ve been on a juicing kick for a while and their health suddenly begins to decline, perhaps they’ll remember this post and “go googling” to find out if maybe, just *maybe* there was something to it. I certainly wish somebody in my social circles (either online or offline) had warned me about the effects of spinach when I was eating multiple salads of it per week. And yes, since I always had spinach in the house during that time period, it was a no-brainer to throw some into any smoothies I made. 🙂
Live and learn!
I’ve had a tremendous positive response via email .. folks who loved the post and had no idea about the danger of oxalates from a daily green smoothie habit.
The vast majority of folks are grateful when information is pointed out about something that they had no idea about and this gives them the opportunity to re-evaluate their dietary choices for the better.
There are always those who get defensive when the error of their ways is pointed out. No worries. It’s not going to slow me down.
An interesting and thoughtful perspective, and one with which I can’t really disagree, but in general a green smoothie – assuming you are not prone to oxalate kidney stones – a few times a month probably has more overall benefits than risks for most people. My feeling is that daily consumption is probably excessive, and the importance of varying ingredients to include a range of organic produce – and not just focusing on greens – in juice and smoothie form (if that’s your thing) is probably advisable for most people. It always comes back to whatever works for an individual. I guess you knew this was going to cause a bit of contention, so kudos for putting it out there! Many thanks!
I don’t have time to read all of the comments unfortunately, and am hoping most of this was pointed out. But although I appreciate the thought that one must be careful about all aspects of their diet, including not assuming just because it is a fruit, veggie or green that it is good for every person to eat in large quantities (or for anyone to eat in *large quantities*). I also think this article is sensationalized and biased in a large way. There should be discussion of the fact that it is entirely possible to make green smoothies/blended salads/juices that are not high in oxalaytes and that if you are avoiding greens for that reason then you should also be avoiding a number of other foods — many many veggies, fruits and nuts as well as grains are high in this *or other* natural food chemicals that can cause problems for SOME people (or if almost anyone if eaten in very large quanitities). So, the basic information of not going crazy about green smoothies or anything else (I’ve done the paleo thing and you can’t tell me eating as much bacon or nuts as many do is healthy either; in full disclosure gree smoothies have been a HUGE part of my own healting process, but I don’t preach them as a panecea for everyone) … “green smoothie” can cover a wide variety of ingredients … blending foods in general can be hugely benficial to those with digestive damage during the healing process (and for some basically forever). Many of us with multiple sensitivies end up feeling like we can’t eat anything when we come across “helpful” articles like this which is why I put this out for others to read — 2 things — first don’t eat the same things at every meal regardless of the “health benefits” of those foods — 2nd look into healing those senstivities with multiple methods (for me homeopathics and acupuncture and meditation are just as important ans what I do and do not eat — yes this means that with these treatments I am less sensitive to these foods so they can become a part of an over all healthy plant-based diet). — IN the end we all want the same thing — good health now and long term … let’s work together
If you have multiple sensitivities, you will likely benefit from reading the following book: “Gut and Psychology Syndrome” by Dr. Natasha Campbell-McBride MD, MMedSci(neurology), MMedSci(nutrition). Best of luck to you.
I never thought I’d be following up on a post I made, but after reading the 98 and counting emails since, I couldn’t help myself. I don’t think anyone is debating the fact that oxalate crystals could be a problem, and from the many comments I’ve read, is a very real problem with some individuals, but the real issue here that so far no one has given any tangible answer to is how much is too much. Our ringleader “Sarah” likes terms like “frequent” “large” and now adding “barrel” to this highly technical conversation we are all having, still dodging the questions since she obviously doesn’t have an answer. I going to go out on a limb with some real numbers to see what this blog community has to say.
We juice between 4 and 7 times a week
Approx 3oz is greens, kale spinach broccoli, any one serving could have one or all
Approx 4-5oz is fruit such as apple, pineapple, kiwi, strawberry. There again any one serving could have one or all
2 carrots
1/2 lemon
Approx 4oz water
There are some real numbers. To be honest I have no idea if anything is too much or not. Besides that fact that I hate reading vague articles geared to stirring people up, I was hoping that someone would post some real information as to where I/we could go for some nutritional facts. I have done some research but it’s like going down the rabbit hole, each question answered brings up 5 new questions, and now oxalate crystals is one of them.
As to Sarah sharing her email about some of us having oxalate crystals on the brain, I believe that would be Sarah and anyone else who has drank her oxalate kool-aid.
There is no knowledge that is not power.
For some real good oxalate information you need to join the yahoo group
I also just did a post about what is in season now and low oxalate.. As well as what constitutes a low oxalate diet (LOD). There are plenty of LOD greens to be eaten. You just need to know what they are.
Just read the low oxalate diet link… that answers one of my questions. I have theoxalates, that’s a given (crystals in my urinalysis). I’ve been sick a very long time and am comensurately poor. I rent a room and have limited kitchen access. Supplements are not in the budget. What can I DO about this??
Calcium citrate, magnesium citrate (both with your green smoothie) and probiotic foods from a variety of sources.
It just occurred to me (I’m a little slow today apparently) that smoothies in general can’t be great for health and weight because they condense so much into an easily consumed product. It’s so typical of our society to think “if a little is good, a lot must be better!” But really, we’ve only had the technology for 50 years or so to purée a smoothies full of veggies and fruits every single day. And those awesome high powered blenders have been around even less time that that. Whether its the oxadate or the sugar content…seriously, what human without a blender could have eaten 2 cups of spinach, 2 pears, a cup of blueberries, 2 tbsps of almonds, a cup of yogurt and 3 carrots … for breakfast? Every day?
Watch Fat, Sick & Nearly Dead – it’s free on hulu –
This will most certainly change your mind 🙂
I’ve seen it – what is it supposed to change my mind about?
I am extremely disapointed in your research on this topic, but I guess a person can’t be perfect all the time. Oxalates only cause problems in ridiculously high amounts…one Green Smoothie a day is NOT going to push someone over the Oxalate edge. For you to actually discourage people from consuming raw fruits and greens is just plain stupidity. The benefits FAR outweigh the risks and anybody that does thorough research will clearly see that you are mistaken. A Green Smoothie per day is EXACTLY what the average person on the standard american diet needs. In fact it could potentially be their only source of real nutrition. Not everybody has access to raw milk. Shame on you for writing this article.
YES…well said Lia : Shame on you!
Maybe just listen to YOUR body, instead of dietary dogma and dictates?