Over the past several weeks it feels like there’s been a surge in news articles and blogs highlighting the dangers of eating raw leafy greens in large amounts.
It’s hard enough already to get anyone to consume more vegetables on principle, what with the trauma of overcooked, tasteless, lifeless dishes of childhood dinners past and a new bacteria contamination recall every day.
Of course, I’m biased, considering I have experienced positive health outcomes from increasing my intake of raw leafy greens over the years and have observed similar outcomes from all of the people I’ve helped make better food choices.
While some of us do better with specific foods and ratios of nutrient components, humans have evolved to be able to eat a wide variety of foods across the plant and animal kingdom. And I mean plant and animal kingdom, not something cooked up in a food scientist’s lab. Regardless of one’s dietary preference, too much of anything can be harmful.
What I find most interested is these articles appear to be specifically targeting green smoothies, and not fresh juicing or raw salads.
The discovery of oxalic acid isn’t (new) news, so what’s up with the green smoothie smear campaign?
What is Oxalic Acid and is it bad for you?
Oxalic acid is a naturally occurring substance found in humans, plants and animals. Human bodies will always have oxalates in some form, and the cells will convert specific substances, like Vitamin C into oxalates. The leaves of a plant will often contain the highest concentrations of oxalic acid, but it is also present in foods like berries, nuts, seeds, grains, chocolate, and black tea.
The information about oxalic acid is, like tons of other health information, conflicting.
I’ve run several oxalic acid searches via search engines and scientific journals, and I have not been able to find a definitive consensus about the harmful effects of consuming foods high in oxalic acid in healthy individuals, other than, too much is harmful. What exactly is too much and how often do you have to consume too much in order for it to be harmful? One, two cups a day? Are we talking one specific vegetable or all of them?
The problem with most scientific studies is how they compartmentalize their test subjects. Oftentimes, studies focus on the effects of a specific behavior of a specific population based on sex, age, and existing health conditions or precursors that is repeated in a controlled environment. Humans are creatures of habit, but we don’t live our lives this way.
Some people will tell you that steaming leafy greens like spinach and kale before adding them to smoothies will reduce their oxalic acid content. But I’ve found several studies that say that cooking doesn’t do much to reduce the oxalic acid content.
Two years ago, The New York Times reported that an elderly woman was hospitalized with a mysterious diagnosis that left her nearly comatose. They discovered that she had been consuming over two pounds of raw bok choy everyday for several months because she thought it would help cure her diabetes.
This case is an extreme example of how too much of anything can be harmful. And while this can happen to anyone who is consuming large amounts of one food over a period of several months, many of us, even the most hardcore raw foodists, are not consuming large quantities of the same raw leafy greens everyday. Cooked or raw, the most studied of us rotate our leafy greens (and all foods) for variety in nutrition and taste.
That said, if you are living with a kidney disorder, gout, rheumatoid arthritis, or a thyroid disorder, then you would fall into that category of folks who need to watch their oxalic acid intake, along with a host of other foods and beverages that can aggravate your symptoms. This is a conversation that you need to be having with your primary healthcare practitioner.
If you’re really concerned, you should consult with your primary healthcare practitioner to determine if you present any markers or habits that would predispose you to conditions in which oxalic acid would be harmful to you.
For the rest of you, don’t give up on your green smoothies just yet.
Eat a wide variety of all kinds of plant-based foods across the color spectrum, and most importantly, listen to your body, as it will be the first to tell you if something you’re doing isn’t the best idea.
Have you been reading about oxalic acid lately? What do you think about all of the reports? Do you plan to cut back on your green smoothies?
Share what you think are the pros and cons of consuming raw leafy greens in the comments.