to eight weeks for the preventive effect to be seen.The explanation for the effect of cranberry juice is probably not an acidification of the urine, because the placebo drink also reduced urinary pH. Rather, cranberries contain a substance that stops bacteria from being able to attach to cells, and this is probably true whether the cranberry juice reaches the bacteria in the digestive tract or the urinary tract. Substances that interfere with bacterial adhesion have also been found in blueberry juice, but not in orange, grapefruit, pineapple, mango, or guava juice.References1. Mahan LK, Arlin M. Krauses Food, Nutrition, and Diet Therapy. W.B. Saunders, Philadelphia, 1992.2. The American Dietetic Association. Handbook of Clinical Dietetics, second edition. Yale University Press, 1992.3. DAmico G, Gentile MG, Manna G, et al. Effect of vegetarian soy diet on hyperlipidemia in nephrotic syndrome. Lancet. 1992;339:1131-1134.4. The American Dietetic Association. Manual of Clinical Dietetics, fifth edition. American Dietetic Association, Chicago, 1996.5. Gretz N, Meisinger M, Strauch M. Does a low protein diet really slow down the rate of progression of chronic renal failure? Blood Purif. 1989;7:33:33-38.6. Barsotti G, Morelli E, Cupisti A, Meola M, Dani L, Giovannetti S. A low-nitrogen, low-phosphorus vegan diet for patients with chronic renal failure. Nephron. 1996;74:390-394.7. 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;328:833-838.8. 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;143:240-247.9. 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 Int Med. 1997;126:497-504.10. Soucie JM, Thun MJ, Coates RJ, McClellan W, Austin H. Demographic and geographic variability of kidney stones in the United States. Kidney Int. 1994;46:893-899.11. Lemann J. Composition of the diet and calcium kidney stones. N Engl J Med. 1993;328:880-882.12. Remer T, Manz F. Estimation of the renal net acid excretion by adults consuming diets containing variable amounts of protein. Am J Clin Nutr. 1994;59:1356-1361.13. Breslau NA, Brinkley L, Hill KD, Pak CYC. Relationship of animal protein-rich diet to kidney stone formation and calcium metabolism. J Clin Endocrinol. 1988;66:140-146.14. Robertson WG, Peacock M, Hodgkinson A. Dietary changes and the incidence of urinary calculi in the U.K. between 1958 and 1976. J Chron Dis. 1979;32:469-476.15. Nordin BEC, Need AG, Morris HA, Horowitz M. The nature and significance of the relationship between urinary sodium and urinary calcium in women. J Nutr. 1993;123:1615-1622.16. Lemann J Jr, Adams ND, Gray RW. Urinary calcium excretion in human beings. N Engl J Med. 1979;301:535-541.17. Soucie JM, Coates RJ, McClellan W, Austin H, Thun MJ. Relation between geographic variability in kidney stones prevalence and risk factors for stones. Am J Epidemiol. 1996;143:487-495.18. Avorn J, Monane M, Gurwitz JH, Glynn RJ, Choodnovskiy I, Lipsitz LA. Reduction of bacteriuria and pyuria after ingestion of cranberry juice. JAMA. 1994;271:751-754. Informacion en EspanolVegan Seafood: Beyond the Fish Shtick for VegetariansSimply VeganVegans Know