Kidney Stones

The formation of stones in the kidneys or urinary tract is a fairly common disorder. The stones are formed from the chemicals usually found in the urine such as uric acid, phosphorous, calcium and oxalic acid. They may vary in consistency from grit, sand and gravel-like obstructions to the size of the bird’s eggs.

The formation of stones in the kidneys is the result of defects in the general metabolism. They usually occur when the urine becomes highly concentrated due to heavy perspiration or insufficient intake of fluids. They are aggravated by a sedentary lifestyle.

The other causes are wrong diet, excess intake of acid-forming foods, white flour and sugar products, meat, tea, coffee, condiments and spices, rich foods and overeating. Lack of vitamin A and an excessive intake of vitamin B may also lead to formation of stones.

The patient should avoid foods which irritate the kidneys, to control acidity or alkalinity of the urine and to ensure adequate intake of fluids to prevent the urine from becoming concentrated.

The foods considered irritants to the kidneys are alcoholic beverages, condiments, pickles, certain vegetables like cucumbers, raddishes, tomatoes, spinach, rhubarb, water-cress and those with strong aroma such as asparagus, onions, beans,cabbage and cauliflower, meat, gravies and carbonated waters.

In calcium phosphate stones, over -secretion of parathyroid hormone causes loss of calcium from the bones resulting in a high blood level of calcium with increased excretion of calcium in the urine. An abnormally high intake of milk, alkalies or vitamin D may also result in the formation of calcium phosphate stones.

For controlling the formation of calcium phosphate stones, a moderately low calcium and phosphorous diet should be taken The intake of calcium and phosphates should be restricted to minimal levels consistent with maintaining nutritional adequacy.

The maintenance level of calcium is 680 mg. and of phosphorous 1000 mg. In this diet, milk should constitute the main source of calcium and curd or cottage cheese, lentils and groundnuts should form the main sources of phosphorous. Foods which should be avoided are whole wheat flour, Bengal gram, peas, soyabeans, beets, spinach, cauliflower, turnips, carrots, almonds and coconuts.

When stones are composed of calcium and magnesium phosphates and carbonates, the diet
should be so regulated as to maintain acidic urine. Insuch a diet, only half a litre of milk, two servings of fruits and two servings of vegetables ( 200 grams) should be taken.

The vegetables may consist of asparagus, fresh green peas, squash,pumpkins, turnips, cauliflower, cabbage and tomatoes. For fruits, watermelon, grapes, peaches, pears, pineapple, papayas and guavas may be taken.

On the other hand the urine should be kept alkaline if oxalate and uric acid stones are being formed. In this diet, fruits and vegetables should be liberally used and acid-forming foods should be kept to the minimum necessary for satisfactory nutrition. When the stones contain oxalate, foods with high oxalic acid content should be avoided.

These foods include almonds, beetroots, brinjal, brown bread, cabbage, cherry, chocolate, French Beans, potatoes, radish, spinach and soyabeans. Uric stones occur in patients who have an increased uric acid in the blood and increased uric acid exertion in the urine. Since uric acid is an end product of purine metabolism, foods with a high purine content such as sweet bread, liver and kidney should be avoided.