Patients often ask about ways that they can help control or prevent urologic illnesses. Most of their questions center on how dietary modifications can affect conditions ranging from stone disease to prostate cancer. Misconceptions about what is actually "good for you" often dominate office visits. One frequent source of confusion centers on renal and ureteral calculi and their prevention and treatment.
Most ureteral calculi in the U.S. are calcium oxalate stones. Less frequent occurrences include uric acid, calcium phosphate, struvite, and cystine, among others. The rapid availability of fast, non-contrast CT scanners for the accurate diagnosis of acute stones, along with improvements in minimally invasive treatment strategies, can move the focus away from prevention. Yet as that ureteral stent is being removed, one of the first questions asked is: "How on earth can I avoid this in the future?"
Recent studies have called into question the age-old suggestion to reduce dietary calcium in all patients with calcium oxalate stone disease. Although there is still the need for most stone formers to increase urine output to >2 liters a day, the dietary changes necessary (if any) depend upon the underlying defect and usually require an outpatient twenty four hour urine collection to sort out.
A metabolic workup can help to individualize treatment of hypercalciuria and, with some patients, reduce the risk of future stone formation. Many patients with calcium oxalate stone disease have already adjusted their diets based on family members' suggestions and the ready availability of information on the internet. Although first time stone formers may not always need a complete metabolic workup, discussion about basic dietary habits can often be revealing. Foods rich in oxalates include rhubarb, green leafy vegetables, spinach, cocoa, beer, coffee, tea, and peanuts.
Cranberries (juice and supplements) are often considered the answer for any and all urologic ills. Despite their high oxalate content, a recent British study showed urinary oxalate levels paradoxically declined with increased cranberry juice intake. Previous studies suggested that cranberry capsules increased oxalates in the urine. The suggestion in the British study is that the oxalate in the juice form is not "bioavailable."
Prostate cancer chemoprevention also remains a concern with few clear answers. With PSA anxiety now a real and measurable phenomenon (Memorial Anxiety Scale for Prostate Cancer (MAX-PC)), it's important that the National Cancer Institute is funding SELECT, a prostate cancer chemoprevention trial with the Southwest Oncology Group. This trial evaluates Vitamin E and selenium as chemoprevention agents. Prostate cancer is the most common tumor in men with 234,460 new cases and 27,350 deaths expected in 2006.
Other potential candidates for prostate cancer chemoprevention include lycopenes (commonly associated with tomatoes), soybeans (phytoestrogens) and fish oils. Patients frequently perceive saw palmetto as a cancer prevention agent, but its main role had been in BPH. Unfortunately, there were two papers presented in 2005 at the American Urological Association's national meeting that suggest no benefit for either saw palmetto or lycopenes; however, a third study suggests that pomegranate juice helped to slow prostate cancer growth as measured by PSA doubling times. Of course, the disclosures for the investigators in the pomegranate juice study revealed funding from POM Wonderful, makers of pomegranate juice.
Bradford L. Moss, M.D., FACS is a partner at Physicians Urology, the largest urology practice in Northeast Ohio. He earned his medical degree from the University of Miami, completed his Urology residency through NEOUCOM and has been board certified for more than fifteen years. Dr. Moss is affiliated with several area hospitals, including Akron General Medical Center, SUMMA Health System and Barberton Citizens Hospital. He specializes in all aspects of general Urology.
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