Do high protein diets increase the risk of kidney stones - Essay Example

Do high protein diets increase the risk of kidney stone formation In the recent years, the increasing progression of obesity among people in industrialized nations, has reached epidemic proportions. The prevalence of overweight and obese adults in the U.S. has reached about 60% of the population and approximately 30% of this populace has been classified as clinically obese (ref). To combat the obesity problem, following various weight- reducing diets have become the latest fad, with high protein diets being the most popular among the list.

Changes in the lifestyle and dietary habits like the reduction of overweight through extreme fasting or low-carbohydrate high-protein weight-loss diets, e.g. Atkins diets have led to the rise and prevalence of kidney stone formation (Siener, 2006). Kidney stones are among the most painful and prevalent of urologic disorders. According to the National Institute of Diabetes and Digestive Kidney Disease, a kidney stone can be defined as a solid crystallized piece of material that forms in the kidney from substances in the urine.

It may be as small as a grain of sand or as large as a pearl. The process of kidney stone formation is medically known as nephrolithiasis or urolithiasis. The most common stones contain calcium in combination with oxalate and/or phosphate. A less common type is caused by urinary tract infection known as struvite or infection stone. Apart from these, there are also other rare types made of pure uric acid stones, cystine stones etc (http://www.ucof.com/education/kidney_stones.php). A number of risk factors like dehydration, improper diet, systemic disorders etc are suggested to be important determinants of stone formation.

Stone formation usually results from an imbalance between factors that promote urinary crystallization and those that inhibit crystal formation and growth (Coe et al, 2005). Some of the known metabolic markers of kidney stone formation include increased level of calcium and uric acid excretion, and a decrease in urinary citrate (Curhan, 2007). These biomarkers were shown to be elevated in individuals prone to stone formation (stone formers) compared to the individuals with no prior history of kidney stones (non-stone formers) (Prie et al, 2001).

In a study conducted by Reddy, Wang, Sakhaee, Brinkley, and Park (2002), the effects of a Low Carbohydrate High Protein (LCHP) diet was looked at in relation to acid-base balance, kidney stone risk and calcium and bone metabolism. Ten healthy subjects participated in a six week metabolic study where Atkins' diet (LCHP) was followed. For the initial two weeks, the participants consumed a severely restricted carbohydrate diet (induction diet) followed by four weeks of a moderately restricted carbohydrate diet (maintenance diet).

The protein content was nearly two fold greater and the carbohydrate content significantly lower in the induction and maintenance diets in comparison to the usual diet. The results of the study indicated a decrease in urine pH, urinary citrate levels and an increase in net acid excretion and urinary calcium levels, showing a positive correlation between high protein consumption and risk for kidney stone disease. The above mentioned study confirmed that dietary pattern and urinary risk factors for stone formation were closely linked together.

For reduction in the occurrence of kidney stone formation incorporating healthy dietary and lifestyle habits like adequate 'dietary' calcium intake, reduction in animal protein intake, salt intake reduction, increase in fruit and vegetable intake and increased fluid intake are recommended (--ref--). In conclusion, low-carbohydrate high-protein diets are popular and are consumed by many people in an attempt to reduce their weight but such a diet delivers an exaggerated acid load implicating an increase in kidney stone risk.

Therefore, when a balanced diet is consumed with adequate fluid intake, the risk of developing a stone can be reduced greatly for both stone formers and non-stone formers. REFERENCESCoe,F.L., Evan, A., Worcester, E. (2005). Kidney stone disease. Journal of Clinical Investigation, 2598-2608.Curhan, G.C.(2007). Epidemiology of Stone Disease. The Urology Clinics of North America, 287-293. National Institute of Diabetes and Digestive and Kidney Diseases, 2007, Retrieved December 10, 2007 from: http://www.nlm.nih.

gov/medlineplus/kidneystones.html).Prie, D, Raver, V, Boccon-Gibod , L, & Friedlander, G (2001). Frequency of renal phosphate leak among patients with calcium nephrolithiasis. Kidney International, 272-276. Reddy, S.T., Wang, C.Y., Sakhaee, K., Brinkley, L., Park, C.Y.C. (2002). Effect of Low- Carbohydrate High-Protein Diets on Acid-Base Balance, Stone-Forming Propensity, and Calcium Metabolism. American Journal of Kidney Disease, 265-274.Siener, R. (2006). Impact of dietary habits on stone incidence.

Urological Research, 131-133.