Every couple of months, somebody writes a terrifying article exposing the impending “health disaster” that is the green smoothie.
And every time one of these articles appear on the Internet, I get bombarded with questions from people who are scared to death to put their lips to a glass of green smoothie.
The most recent green smoothie scare comes from a blog called The Healthy Home Economist in an article titled How Green Smoothies Can Devastate Your Health. The blog post focuses on the oxalic acid content of leafy greens, particularly spinach.
Oxalic acid isn’t anything new. Nobody blew the lid off of the fact that leafy greens contain varying, but not toxic, levels of oxalates. But what this blog post did was instill a lot of baseless fear (using massive, unscientific assumptions) about drinking green smoothies and eating leafy greens. After reading the article, I only see one (just one!) source mentioned.
Instead of writing a compelling argument about how leafy greens negatively affect health, they instead rehashed one article written by a William Shaw, PhD, that is published on the Weston A. Price website.
A very brief Google search on William Shaw brings up some cited criticism about some of his dubious, and unvalidated hypotheses, particularly relating to post-natal causes of autism (oxalates is supposedly one of them) for which absolutely no scientific evidence exists.
Basically, the ideas of William Shaw, PhD, should be taken with a healthy grain of salt, and cross referenced against information from other scientific sources to see if they hold up under scientific scrutiny, which they do not.
And this is precisely why you can’t just accept anything you read or hear from one expert. It is also why you never write an entire blog post based on the research pulled from just one source!
But I digress.
Is Oxalic Acid From Leafy Greens Really A Health Disaster?
Should leafy greens and green smoothies be avoided because they contain oxalates? The vast majority of credentialed scientists and health experts will say no. In healthy individuals, the oxalate content of leafy greens, as well as fruits, berries, nuts and seeds (greens aren’t the only source of oxalates), will have no detrimental health effects unless foods high in oxalates are consumed to excess.
Putting two handfuls of baby spinach in a green smoothie every day isn’t going to cause kidney stones. There is simply zero scientific evidence for that. (I should probably have a football-sized boulder in my kidneys by now, right?)
And the vast majority of people who suffer from calcium-oxalate kidney stone formation have never had a green smoothie in their life. Kidney stones happen in some people whether or not they drink green smoothies, consume leafy greens regularly, or avoid leafy greens altogether, as most people in the United States do.
Unless a qualified doctor has diagnosed you with a medical condition that warrants limiting your intake of oxalate-containing foods, there is absolutely no health benefit to cutting spinach or other leafy greens from your diet. In fact, avoiding leafy greens because of an unfounded oxalate phobia only serves to deprive you of all the good stuff in greens and green smoothies.
Nutritional Tunnel Vision
One of the biggest problems with the natural health movement is that people (both experts and those who follow them) are so focused on isolated nutrients or anti-nutrients that the big picture of health is missed. Absolutely every food you eat has a downside – even the healthiest, organic and bio-dynamic food out there. Every breath of air, every sip of water, every bite of food, has both good and bad things in it, and your body is well equipped to handle it all just fine.
Focusing on the oxalate content of leafy greens is silly. It’s as silly as avoiding bananas because they contain fructose, or avoiding kale because of glucosinolates, or avoiding breathing air because oxygen is toxic. Yes, oxygen is toxic, but it’s not toxic in the amount found in the air at the Earth’s surface. And the oxalate content of edible leafy greens are not toxic in the amount found in normal portions you would put in a daily green smoothie.
I encourage you to cast off the nutrition-fear blinders and take a step back from the noise of conflicting opinions about health and nutrition. Focus on the big picture of health – whole foods, exercise, plenty of water, friendship, sunshine and spending as much time as you can doing what you love.
Therein lies the key to health, not to mention the peace of mind and serenity to enjoy what you eat without worrying about all the conflicting opinions that are out there about what you put in your body.
And you might suspect that I am motivated to defend green smoothies because I write a green smoothie blog. Fair enough, but look at the science (not just opinion). Read my articles and then look at my sources (I list more than just one on my article on oxalates).
Don’t just read articles written by holistic doctors. Compare what they write and say against what is discussed in peer-reviewed scientific journals.
But above all, don’t worry about isolated nutrients or supposedly toxic compounds in otherwise healthy fruits and vegetables, unless a diagnosed medical disorder warrants it. An exposé about the health disaster of any fruit or vegetable (or generally considered healthy food, for that matter) is simply noise that only serves to distract you from the big picture of health.
So go ahead and raise a glass of green smoothie to your health. I’ve been doing it every day for almost five years now!
Tracy Russell is the creator of the Green Smoothie Weight Loss Program, the 30-Day Whole Foods Challenge and founder of Incredible Smoothies. She is passionate about helping people improve their health with green smoothies and a whole foods lifestyle.