Does soy bean contain much oxalate?

Soy beans and soy products are very healthy food. But, we know that legumes are high in oxalate which can increase the risk of kidney stones.

Soy beans, a legume and soy products like soy milk, tofu, soy energy bars or anyother product which contains them are rich in oxalate. The levels of oxalates are far above than is recommended for those who suffer with kidney stones.

The American Dietetic Association suggests that patients with calcium oxalate kidney stones limit oxalate levels to no more than 10 milligrams per serving. Some of the soy products contain more than 50 times of this. Texturized soy protein has 638 milligram per average serving of almost 3 ounces. Soy cheese contains 16 milligram per servings.

Oxalate has no nutritive value. Healthy persons usually pass it from their body in urine without any problem.

There are many legumes or vegetables which also have much oxalate.

What are kidney stones?

Kidney stones are hard masses developed from crystals which separate from the urine in the kidney or in the urinary tract. Urine contains chemicals that prevent or inhibit the crystals from forming and most of the time these crystals remain tiny to travel through the urinary tract without pain and pass out of the body in the urine without being noticed. But the bigger stones can block the renal pelvis and tubes completely. It is very painful. There are different kidney stones.

Kidney stones, like the other modern chronic diseases, appear to be another factor from a westernized diet which influences a lot to produce it.

Developing a kidney stone depends on several factors, including hereditary, diet, medication, metabolic abnormalities and infections.

There are four kinds of kidney stones:

• Calcium oxalate stone – 80 to 90% of the kidney stones are calcium oxalate stones. Much calcium is present in milk and milk products. Oxalic acid or oxalates are present in vegetables.

• Cystine stone – is the least common stone. It has nothing to do with the food but is caused by hereditary disorders. An excessive excretion of this amino acid is the reason for this stone formation.

• Magnesium phosphate or ammonium phosphate or a mixture of this also produces the kidney stones. These are mostly formed in infected urine.

• Uric acid stone – uric acid is the by product of protein metabolism which also form stones and it is caused due to excessive intake of proteins.

Extremely acidic urine forms stones. We must drink enough water to prevent the stones.

I heard that eating spinach often may cause kidney stones, is it true?

Yes, because we need calcium and oxalic acid for kidney stone formation. Since spinach is rich in oxalic acid, the risk for kidney stone formation is there.

If you consume more calcium then the risk increases. More than 90% of the kidney stones are calcium oxalate stones.

I am not telling you to avoid spinach. The easy way to avoid this risk is, drink a lot of fluids. Three to four litres a day and 70 to 80% of this must be water, aerated or pure drinking water and then you need not worry about the kidney stones. If you are sweating more, then you have to drink more.

There are several other vegetables which have more oxalic acid than spinach. If you are prone to kidney stone formation, eat less spinach and other vegetables containing oxalates.