Pros and Cons of a Daily Spinach Diet

The Spinach Queen and The Sailor Man

Spinach is a favorite topic of nutritionists, fitness experts and culinary chefs who have created thousands of articles and blogs posted across the web about the wondrous properties of spinach..  And to remain in congruity with the law of information balance, i.e. two sides to every coin, there are those who pour cold water on the health benefits of eating raw spinach...so we have a considerable degree of conflicting opinions.  What fun!

This post is dedicated to the memory of the cartoon sailor that popularized the spinach diet--“Popeye the Sailor" who conducted a great deal of applied research on the merits of eating spinach!  Although Popeye’s power boosting spinach owes its fame to a clerical error that misstated the actual iron content of spinach by ten-fold back in 1870, it does sport many healthy attributes—so carry on Popeye.

News Update:

Since I originally posted this article, and after three consecutive years of daily spinach consumption, I have changed my opinion as to the risk of elevated oxalate levels  Here is an update you might want to view after reading this introductory article.

Pros and Cons of a Daily Spinach Diet Update: the Bad News and the Good News

Spinach History Snapshot

In this review, I summarize a few key points about the plusses and possible minuses of a diet rich in spinach and provide a catalog of relevant sources.  In spite of the current tensions with Iran, we owe Iranians a hearty thanks.  Spinach, a relative of chard, originated in Persia and by the year 687 AD had been introduced into China...and eventually to the British Isles where...

Spinach was the favorite vegetable of Catherine de Medici, a historical figure in the 16th century. When she left her home of Florence, Italy, to marry the king of France, she brought along her own cooks, who could prepare spinach the ways that she especially liked. Since this time, dishes prepared on a bed of spinach are referred to as "a la Florentine."  Source

Although I (like most) may only be very, very remotely related to Queen de Medici, I do share her fondness for spinach.  And I doubt that my passion for spinach is a result of childhood Popeye cartoon brainwashing, because I detested that awful, gooey concoction in a can....and as far as I recall, my grandmother—farm dueña—didn’t grow it in her kitchen garden.

My fascination with spinach began two years ago when I became determined to lose weight and get in shape by eliminating, starches, meat, alcohol, fat, pizza, beer.... and opted in for a vegetable diet based on the classic dinner salad.  I became a vegan of sorts.

After a few months of Parris Island romaine and red leaf lettuce ensaladas, the recipe needed a boost and I added some spinach to the mix.  I liked spinach before, but it was not a focal point of my diet consciousness, so I didn’t have a pressing gastronomic need to do this, I just boosting supper variety.  I was surprised how much more springy texture there was in spinach and how much more flavor it has compared to lettuce.  Vegans, let’s face it--most lettuce is pretty flavorless, but spinach packs a subtle, woody, earthy aroma with a nice crunchy bite.  Try savoring spinach raw without burying it in a dressing, it is quite enjoyable on its own.

Manifold Health Benefits

[Be sure to consult your physician before adding spinach to your diet.  As described below, some vocal health experts claim that spinach consumption may lead to health problems including the formation of kidney stones and vitamin deficiencies.]

Spinach is generally regarded as a rich source of antioxidants and many vitamins and minerals and has been identified to have substantive healing attributes for critical organ systems including:  eyes, skeletal and digestive systems and prostrate gland.  Many of the benefits of spinach are expressed in terms of reducing risk or damage.  For example, spinach has been linked to decreased risks of oxidative stress and high blood pressure and other eye-related problems.  Recently, spinach has been credited with anti-aging effects in vision, brain and cardiovascular function.

Calorie for calorie, leafy green vegetables like spinach with its delicate texture and jade green color provide more nutrients than any other food... Among the World's Healthiest vegetables, spinach comes out at the top of our ranking list for nutrient richness. Rich in vitamins and minerals, it is also concentrated in health-promoting phytonutrients such as carotenoids (beta-carotene, lutein, and zeaxanthin) and flavonoids to provide you with powerful antioxidant protection.  Source  

Cuisine d'Spinach:  New-Humans ‘Frisky’ Spinach Salad

I am a devoted fan of the simple “Frisky” ultra-fresh spinach salad.  The ‘frisky’ fun part of spinach is that no matter how careful I am about transporting it from the garden or bag or box to the strainer for a rinse or to the plate for dinner, some leaves manage to jump out into the sink or onto the kitchen floor.  This seldom happens with lettuce, but nearly every day with spinach!

The New-Humans ‘Frisky’ Spinach Salad consists primarily of a large portion of fresh baby spinach with tomato and avocado.   This combo serves as the faithful daily evening constant with the variables being the type of tomato, and options of the day, like sliced raw broccoli, cucumbers, and once in a while, a scoop of low fat cottage cheese.  The dressing I favor is virgin olive oil with a little vinegar and water.  The vinegar also offers its own health benefits.  Source 

Whatever you choice of dressing,  I recommend only applying it to half of the salad so you can still enjoy the full, natural taste of fresh spinach, tomato and avocado. For the latest spinach recipes and growing tips that are updated daily, visit the New-Humans Metamorphosis Club and check out the daily Spinach Alert in the right column of the blog.  The Food Network Website maintains a list of over 500 spinach recipes.  

The Health Controversy Over Eating Too Much Spinach

There seems to be solid support for the premise that consuming spinach is generally good for you.  However, opinions vary about the health repercussions of including spinach in a daily diet regimen.

There seem to be two primary health concerns:

1.  the effect of spinach oxalates on nutrient absorption
2.  the effect of spinach oxalates on kidney stone formation

The adsorption problem with spinach is that although it contains high amounts of calcium and iron, it also contains compounds that absorb and inhibit the availability of both elements.  Called oxalates and phytic acids, these compounds bind to iron and calcium making them unavailable biologically.

The argument that daily spinach intake increases the risk of kidney stone formation is based upon the assumption that during digestion, the oxalates and calcium in spinach combine to form calcium oxalate--the compound most often associated with kidney stones.  (Source)  However, as we shall see, not all nutritionists take this potential threat seriously.

Pros and Cons of a Daily Spinach Diet

I have organized the pros and cons into three main groups:  
·  Red Flag
·  Yellow Flag
·  Green Flag

Red Flag

Here is the worst case position as voiced by Dr. William Shaw of the Great Plains Laboratory.

People who are vegetarians really have to be aware of all the oxalates they take in. The biggest culprit for all vegetarians is soy protein, and the second is spinach. Virtually everybody who eats a large spinach salad every day is going to succumb to kidney stones. I’ve tested them over and over again and the people who have the highest oxalate values invariably tell me that a cornerstone of their daily diet is a large spinach salad. If they add nuts to their salad and textured soy protein, both of which are very high in oxalates, you’ve got a cocktail made to produce kidney stones. Spinach is so high I would not recommend eating it even cooked, as a main course. Source  

 Eat a big spinach salad everyday and it is virtually certain you will eventually succumb to kidney stones, according to Dr. William Shaw, Director of The Great Plains Laboratory for Health, Nutrition and Metabolism.  Source

Yellow Flag

Not so fast, many others either mildly disagree or explicitly dismiss Dr. Shaw’s contentions.  in the mildly disagree--yellow flag camp are those that accept the idea that oxalates in spinach may interfere with the absorption of calcium or iron, so they recommend boiling, steaming, or micro-waving spinach prior to consumption.  They maintain that heat breaks down the oxalate preventing it from bonding with calcium or iron.

Spinach is only one of three vegetables we recommend boiling to free up acids and allow them to leach into the boiling water; this brings out a sweeter taste from the spinach. Discard the boiling water after cooking; do not drink it or use it for stock because of its acid content.  Source 

But, other nutrition experts believe that cooking is ineffective, so why bother?

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.  Source 

Block the oxalate...at the source.

The Center for Disease Control and Prevention recommends eating spinach with citrus or tomatoes. These foods are high in vitamin C, which changes the form of iron in spinach to the easily absorbed kind you find in steak–but with much fewer calories or risks to your health. Vitamin C also blocks the oxalate from binding to calcium, encouraging further absorption. Source 

B-12 Vitamin Deficiency

If you (as do I) shun feeding on all animal flesh, you may be susceptible to B-12 vitamin deficiency.  Luckily there are several easy remedies.  See B-12 Alert!

·Green Flag

The oxalate threat  has been overstated is pretty much the opinion of the pro-spinach-diet enthusiasts.

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.  Source  

This author suggests that taking calcium supplements while ingesting spinach actually avoids the risk of kidney stone formation.

Healthy individuals can safely consume such [oxalate -rich] foods in moderation, but those with kidney disorders, gout, rheumatoid arthritis, or certain forms of chronic vulvar pain (vulvodynia) are typically advised to avoid foods high in oxalic acid or oxalates. Conversely, calcium supplements taken along with foods high in oxalic acid can cause oxalic acid to precipitate in the gut and drastically reduce the levels of oxalate absorbed by the body (by 97% in some cases.)  Source

The George Mateljan Foundation’s “World’s Healthiest Food Website”... takes a more upbeat approach. 

For the vast majority of individuals who have not experienced the specific problems [absorptive hypercalciuria type II, enteric hyperoxaluria, primary hyperoxaluria, and nephrolithiasis], 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.  Source 

“The George Mateljan Foundation, a not-for-profit foundation with no commercial interests or advertising, is a new force for change to help make a healthier you and a healthier world.”

This sounds right to me and I am sticking with my daily ‘frisky’ spinach salad with tomatoes and avocado and taking calcium supplements.  In this limited space, I have only attempted to summarize some of various viewpoints and opinions expressed on the web  and recommend you do more research and discuss your diet with your physician.

If you have a different viewpoint or know of any controlled experiments that might shed light on the spinach/stone connection, please leave a comment or e-mail me at nolan@new-humans.com.

Spinach Sources

According to the USDA Pesticide Data Program, 48 pesticide residues have been found in spinach, probably because keeping the bugs away from this delicacy takes a lot of effort.  Lucky for us, that’s where organic farm production comes to the rescue.

Farmers’ Markets

The weekend farmers’ market is a great “no pesticide” tainted spinach.  For example, spinach raised organically by Avila Farms in Hollister, California. is available at the SeaScape Market in Aptos on Sundays.  This is a good chance to talk with a farmer, like Phil from Avila Farms to learn more about the biology and ecology of growing spinach.

Here, Phil is displaying freshly picked spinach bursting with health and flavor.

Buy Organic Spinach in Plastic Containers?—Yikes!

This has been a tough choice for me because our planet is choking on plastic and I avoid it as much as possible.  But not long ago I noticed a lady at the local Safeway store who was using the disinfectant stand at the entrance (which I have never really paid attention to before) and she even wiped down the push bar on the cart.  So watching someone clean their hands before shopping reminded me that most people never do and that anyone can dig around in the fresh produce section to find just the bunch of spinach that they favor (which I used to do) and you have no idea where their hands have been or what germs they may be carrying.  Store spinach is also frequently sprayed to keep it moist which makes it more likely that germs from shoppers hands will be transmitted to the leaves.

Did you ever watch a shopper pick through the lettuce at the store and drop a leaf or two on the floor then replace them in the bin to be selected by the next unwary shopper?  It seems to me that the whole concept of fresh produce storage and marketing  needs to change.  Imagine how easy it would be for terrorists to contaminate the produce section just by administering a virus like Ebola may be transmitted by physical contact.

This would likely result in a panic that would bring the fresh produce sales in the big supermarket chains to a screeching halt as consumers realize that entire fresh produce distribution and marketing  system is vulnerable.  I intend to explore this vulnerability in a future essay for the New-Humans Longevity News.

Since I am obviously concerned about shopper germs and willing to buy spinach in plastic containers, what about storing food in plastic containers?  Is it safe?

Many people are concerned about the nutrient content of delicate vegetables (like baby spinach) when those vegetables are placed in clear plastic containers in grocery store display cases and continuously exposed to artificial lighting. One recent food study has shown that you don't need to worry about the overall status of antioxidants in baby spinach that has been stored and displayed in this way.  Source 

So if I can’t make it to the local farmers’ market and have to go to the supermarket, I buy the big tub which can be used for all sorts of projects and recycled as a last resort.

Grow Your Own Spinach

This is my favorite source and I am getting better at growing my own.  This is one of my inventions called the “Mobile Urban Garden System^TM” which offers a terrific way to grow spinach.   As I learn more about the art of spinach micro-farming, I will share it here on the New-Humans Metamorphosis Club Blog.

  

This is a mix of Broomsdale (crinkled leaves), Olympia Hybrid (flat leaves) and Tyee (in between crinkled and flat).  Being able to regularly eat something healthy that you have grown yourself is a feature of the New-Humans Fitness Program.  The advantage of spinach is that you can snip the leaves and the plant continues to produce.  It is a  superbly beneficial relationship that we have with our mutually symbiotic spinach partners.

Wind Up

I lost about 50 pounds on a diet based on spinach as the daily foundation.  However, diet is only part of the picture, exercise and attitude are the rest.  For those interested in the latest in exercise fitness, I explore the merits of stick twist exercises in, “Fast Twitch Fibers and Body Sculpting--are fitness enthusiasts missing out?”

News Update:

Since I originally posted this article, and after three consecutive years of daily spinach consumption, I have changed my opinion as to the risk of elevated oxalate levels  Here is an update. 

Pros and Cons of a Daily Spinach Diet Update: the Bad News and the Good News

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All Rights Reserved.

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nolan@new-humans.com