oxalic acid

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Oxalic Acid Controversy

By | 2017-10-29T15:41:24+00:00 August 11th, 2012|Health Tips, Nutrition|

Are you one of the many people who are afraid of eating greens because you have heard the possible dangers of eating too much oxalic acid?  Greens, like certain plant foods are high in oxalic acid.

You might already guess my stance on this controversy but just in case there is any confusion I will spell out my personal reaction to these concerns at the end of this post.

The Problem with Oxalic Acid:

1.  It binds with some nutrients, making them inaccessible to the body. To eat large amounts of high oxalic foods over a period of weeks to months may result in nutritional deficiencies, most notably of calcium.

2. It has been is associated with the formation of kidney stones.  If you have kidney problems, your doctor may advise you against eating foods with high levels.

3.  Oxalic acid poisoning symptoms include weakness, burning in the mouth, death from cardiovascular collapse, on the respiratory system, throat – burning in the throat, abdominal pain, nausea, vomiting, diarrhea, convulsions, and coma.

4.  Individuals with gout, rheumatoid arthritis, or certain forms of chronic vulvar pain are advised to avoid foods high in oxalic acid or oxalates.

For Clarity: How toxic is Oxalic Acid?

“From an MSDS (Material Safety Data Sheet) for Oxalic acid, LD50 (LD50 is the Median Lethal Dose, which is the dose of a drug or chemical predicted to produce a lethal effect in 50 percent of the subjects to whom the dose is given) in rats is 375 mg/kg. So for a person about 145 pounds (65.7 kg) that’s about 25 grams of pure oxalic acid required to cause death. Rhubarb leaves are probably around 0.5% oxalic acid, so that you would need to eat quite a large serving of leaves, like 5 kg (11 lbs), to get that 24 grams of oxalic acid. Note that it will only require a fraction of that to cause sickness.”  – The Rhubarb Compendium

Is This Possible?  The Murky Middle

  • Oxalic acid is a naturally occurring substance in plants, animals, and in humans.
  • I often think that anything with the word acid in it will scare people but not all acid are bad.  Remember that Omega 3 which everyone is trying to put into their bodies is an essential fatty acid. That might be a bad example of course since everyone is also scared of the word ‘fat’.
  • Rhubarb contains high amounts of oxalic acid.  If your weight is 145 pounds, you would have to consume about 25 grams of pure oxalic acid to cause death. That means you would have to eat about 11 pounds of rhubarb!
  • Foods that contain significant amounts of oxalic acid are ( in order from highest to lowest): buckwheat, star fruit, black pepper, parsley, poppy seed, rhubarb stalks, amaranth, spinach, chard, beets, cocoa, chocolate, most nuts, most berries, and beans. If you had to really avoid it in your diet, that would be […]