Stones and Diets - Myths

Many stone patients follow a variety of dietary patterns in effort to decrease their risk of recurrent stones. Unfortunately, much of this information is either old, true in theory only or just plain wrong. In general, we agree with Benjamin Franklin that "everything in moderation" is the best approach to diet and life.

Only water works for prevention - Many people believe that only water is effective for stone prevention. Unfortunately, this belief frustrates many stone formers who say that they don't like to drink water or their water at home tastes "bad". Population studies show clearly that the more of ANYTHING that people drink, the less likely they are to make stones. This makes sense because anything that you can put in a glass is almost entirely water with some added color and chemicals like sugar to give it some taste.

Coffee, tea and carbonated drinks cause stones - Many people believe that these drinks cause stones for a variety of reasons. There is popular concern that the caffeine in coffee, which is a mild diuretic (makes more urine) may be dehydrating. Some teas may be high in oxalate as well as caffeine. There is an incredibly common misunderstanding that carbonated beverages cause stones. Population studies clearly show that there is no increased risk of stone formation with any of these drinks. Whatever potential risks may be associated with caffeine, oxalate or soda appears to be overwhelmed by the preventative effects of the water which makes up the vast majority of the drink. The only drink which has actually been shown to increase risk of stones is grapefruit juice but the mechanism for this effect is not well understood.

Alcohol causes stones - There is concern that the diuretic effect of alcohol may dehydrate people and be a risk for stone formation. Interestingly, in population studies, beer and wine were found to significantly decrease the risk of stone formation. While it is not recommended that stone patients drink excessive amounts of alcohol, moderate alcohol use should not increase the risk of stone formation.

Vitamin C is causes stones - The chemical name for Vitamin C is ascorbic acid which the body may break down to oxalate. While megadose ingestion of Vitamin C is controversial for many reasons, there does not appear to be an impact on stone risk in population studies.

References

1: Taylor EN, Stampfer MJ, Curhan GC. Dietary factors and the risk of incident kidney stones in men: new insights after 14 years of follow-up. J Am Soc Nephrol. 2004 Dec;15(12):3225-32.

2: Curhan GC, Willett WC, Knight EL, Stampfer MJ. Dietary factors and the risk of incident kidney stones in younger women: Nurses'' Health Study II. Arch Intern Med. 2004 Apr 26;164(8):885-91.

3: Taylor EN, Curhan GC. Role of nutrition in the formation of calcium-containing kidney stones. Nephron Physiol. 2004;98(2):p55-63.

4: Curhan GC, Willett WC, Speizer FE, Stampfer MJ. Twenty-four-hour urine chemistries and the risk of kidney stones among women and men. Kidney Int. 2001 Jun;59(6):2290-8.

5: Curhan GC, Willett WC, Speizer FE, Stampfer MJ. Intake of vitamins B6 and C and the risk of kidney stones in women. J Am Soc Nephrol. 1999 Apr;10(4):840-5.

6: Curhan GC, Willett WC, Speizer FE, Stampfer MJ. Beverage use and risk for kidney stones in women. Ann Intern Med. 1998 Apr 1;128(7):534-40.

7: Curhan GC, Willett WC, Speizer FE, Spiegelman D, Stampfer MJ. Comparison of dietary calcium with supplemental calcium and other nutrients as factors affecting the risk for kidney stones in women. Ann Intern Med. 1997 Apr 1;126(7):497-504.

8: Curhan GC, Willett WC, Rimm EB, Stampfer MJ. A prospective study of the intake of vitamins C and B6, and the risk of kidney stones in men. J Urol. 1996 Jun;155(6):1847-51.

9: Curhan GC, Willett WC, Rimm EB, Spiegelman D, Stampfer MJ. Prospective study of beverage use and the risk of kidney stones. Am J Epidemiol. 1996 Feb 1;143(3):240-7.

10: Curhan GC, Willett WC, Rimm EB, Stampfer MJ. A prospective study of dietary calcium and other nutrients and the risk of symptomatic kidney stones. N Engl J Med. 1993 Mar 25;328(12):833-8.