The People's Perspective on Medicine

Be Wary of Too Much Green Juice

Drinking green juice made of oxalate-rich foods like beet greens, kale or parsley could overwhelm the kidneys and result in painful kidney stones.

Whenever you start doing something different because it is supposed to be good for your health, it makes sense to check out the possible consequences. Sometimes people find that the cure is worse than the disease. That is what this reader discovered, through her husband’s experience:

Q. I recently found out that something that could be great for you might also end up causing problems. My husband was drinking a daily green juice comprised mainly of parsley and kale for many months. He got hit with kidney stones. It turns out that parsley, kale and beets are very high in oxalates, which contribute to kidney stone formation.

A. Juicing is a way to consume concentrated amounts of nutrients easily. As you point out, this could be helpful in some cases. On the other hand, people juicing foods rich in oxalates such as parsley, beets with greens, collard greens and spinach could easily overdo. This is particularly true for anyone who has already experienced a kidney stone, as they are at higher risk for another.

The Hazards of Green Juice

A case report from the Mayo Clinic describes an 81-year-old whose kidney function dropped suddenly after he began juicing all his meals in an attempt to lose weight (American Journal of Medicine, Sept., 2013).

It isn’t only people trying to lose weight who have taken up juicing. Others are simply trying to maximize their nutritional intake of green vegetables, with all their magnesium, potassium, folic acid, vitamin C and other helpful ingredients.

Controlling Blood Pressure

Some folks want to lower their blood pressure with beet juice. They too should be aware of this risk, especially if they have ever had a kidney stone. Drinking green juice with beet or collard greens, kale or parsley could provide too much oxalate for their kidneys to handle.

You can learn more about beet juice and other non-drug approaches to hypertension control in our Guide to Blood Pressure Treatment.

Rate this article
5- 42 ratings
About the Author
Joe Graedon is a pharmacologist who has dedicated his career to making drug information understandable to consumers. His best-selling book, The People’s Pharmacy, was published in 1976 and led to a syndicated newspaper column, syndicated public radio show and web site. In 2006, Long Island University awarded him an honorary doctorate as “one of the country's leading drug experts for the consumer.” .
Blood Pressure Treatment

Download these eight pages on the pros and cons of the various medicines used to lower blood pressure. Details on non-drug approaches to blood pressure control such as diet, supplements and special foods.

Blood Pressure Treatment
Join over 150,000 Subscribers at The People's Pharmacy

We're empowering you to make wise decisions about your own health, by providing you with essential health information about both medical and alternative treatment options.

Showing 5 comments
Add your comment

I’m considering adding juicing to my already very healthy daily regimen. Obviously it’s an easy way to get more greens into the diet. Sometimes I catch a little of that late-nite infomercial for a certain company’s “Bullet,” which purportedly extracts many more nutrients from foods because it totally pulverizes them. In fact, they market it like a medical device, putting “Rx” after the name. MY QUESTION: Isn’t it a fact that thoroughly chewing one’s fruits and veggies extracts just as many nutrients, and therefore liquidizing them isn’t necessary? Or conversely, does using such a machine really make a big difference? (PS, I know this isn’t exactly to the point of your article.) Thanks.

I have read that even fresh squeezed orange juice has more sugar than a Coke.
And I do love it. So I limit fruit juices period.

Eat the fruit instead. It will take longer for solids to hit the blood stream than a juice.

Wow! I had also begun juicing several months ago, mostly to increase my husband’s intake of nutrients; I eat salad for lunch almost every day. I used greens, cilantro was a particular fave; however, I also used green leaf and romaine lettuces. Tomatoes, cucumbers, carrot, and a fruit. All around nutrition and I don’t care for a green taste.

I also did not like the idea of losing all that pulp; that fiber is food for the beneficial bacteria that live in your gut. I don’t make enough soup in the summer to use up all that pulp, I tried it in salads and stir fries, yuck, so we were throwing it away. Then my husband said something about the juice was irritating his throat and he no longer was willing to drink it. Perhaps to the good as I have already had a stone in my only kidney. And passed it, a horror I do not wish to repeat. Thank you for this information; tho I have read about oxalates and greens, I did not connect the dots to the juice I was making.

Many of those greens are good sources of calcium. Wouldn’t the calcium and oxalate combine in the gut, reducing the oxalate that is absorbed into the bloodstream?

That is almost certainly what happens when you eat them. Juicing them just increases the quantity of oxalate more than some people’s systems can handle.

* Be nice, and don't over share. View comment policy^