RESUMO
OBJECTIVES: Acidic urine pH may be protective against recurrent urinary tract infections (RUTIs). After reviewing the literature, we primarily analyzed urine pH fluctuations and secondarily compared them with diet in older women with RUTIs. METHODS: After IRB approval, postmenopausal women with documented RUTIs were enrolled. Participants were given preformatted charts to record urinalysis reagent strips (Medimpex) findings 4 times per day and concomitant food/beverage intake (food diary). Urine cultures at baseline ensured no infection during measurement period. Nutrient content reported in food diaries was analyzed by an experienced registered dietitian and compared with parallel fluctuations in urine pH. RESULTS: Of 26 women with median age of 72 years (55-86 years), the first 3 days of diet and urine pH recordings found that 17 (65%) of 26 exhibited urine pH variation greater than 1 unit, with an overall median of 6 (5-9). Comparing dietary analysis and urine pH changes, beta-carotene (P = 0.017) and total dietary sugar intake (P = 0.036) were associated with a decrease in urine pH, whereas monounsaturated fatty acids (MFA, 22:1, P = 0.023) and protein (P = 0.028) were associated with an increase in urine pH. CONCLUSIONS: In this real-life, observational study, 65% of older women with RUTIs exhibited notable changes in urine pH, with decreased urine pH associated with nutrients found in orange and yellow vegetables and several major food groups. A longitudinal study is needed to determine if changing an individual's diet and/or adding supplements could decrease the urine pH, thus affecting the rate of RUTIs.