1 3 World J Urol DOI 10.1007/s00345-015-1611-7 ORIGINAL ARTICLE Cranberry fruit powder (Flowens™) improves lower urinary tract symptoms in men: a double-blind, randomized, placebo-controlled study Ales Vidlar 1 · Vladimir Student Jr. 1 · Jitka Vostalova 2 · Emilie Fromentin 3 · Marc Roller 4 · Vilím Simanek 2 · Vladimir Student 1 Received: 9 April 2015 / Accepted: 31 May 2015 © Springer-Verlag Berlin Heidelberg 2015 500-mg groups, p = 0.05 and p < 0.001, respectively) ver- sus the placebo group (-1.5), and a dose–response effect was observed. There were significant differences in Q max , Q ave , PVR, and Vol in the Flowens™ 500-mg group ver- sus baseline (p < 0.05). A dose-dependent effect on Vol was observed, as well as on PVR, for participants with a nonzero PVR. There was no effect on clinical chemistry or hematology markers. Conclusions Flowens™ showed a clinically relevant, dose-dependent, and significant reduction in LUTS in men over 45. Keywords Vaccinium macrocarpon · Cranberry · Lower urinary tract symptoms · Benign prostatic hyperplasia · IPSS Background Lower urinary tract symptoms (LUTS) become increas- ingly bothersome as men age, with a prevalence of mod- erate-to-severe symptoms rising to nearly 50 % of men in their eighties [1]. LUTS may be related to benign prostatic hyperplasia (BPH) that occurs in 50 % of men in their 50 and 90 % of men in their eighties [1] or can arise from age- related bladder detrusor dysfunction and other sympathetic conditions [2]. LUTS are measured using the international prostate symptoms score (IPSS), a validated tool, widely used among the medical community [3]. Although LUTS are not a life-threatening condition, its impact on quality of life (QoL) can be significant and treat- ment is necessary in most cases to avoid complications [4] and in certain cases, surgery may be recommended. Upon diagnosis, watchful waiting is recommended in approxi- mately 34 % of cases in the USA [1]. Abstract Background Lower urinary tract symptoms (LUTS) and benign prostatic hyperplasia increase with age. To date, several medications are available to treat LUTS, including herbal remedies which offer less side effects but lack robust efficacy studies. Methods This 6-month, randomized, double-blind, pla- cebo-controlled study aimed at evaluating the dose effect of 250 or 500 mg cranberry powder (Flowens™) on LUTS and uroflowmetry in men over the age of 45. A total of 124 volunteers with PSA levels <2.5 ng/mL and an inter- national prostate symptoms score (IPSS) score ≥8 were recruited and randomized. The primary outcome measure was the IPSS, evaluated at 3 and 6 months. Secondary out- come measures included quality of life, bladder volume (Vol), maximum urinary flow rate (Q max ), average urinary flow rate (Q ave ), ultrasound-estimated post-void residual urine volume (PVR), serum prostate-specific antigen, sele- nium, interleukin 6, and C-reactive protein at 6 months. Results After 6 months, subjects in both Flowens™ groups had a lower IPSS (-3.1 and -4.1 in the 250- and * Emilie Fromentin e.fromentin@naturex.com 1 Department of Urology, University Hospital, Olomouc, Czech Republic 2 Department of Medical Chemistry and Biochemistry, Faculty of Medicine and Dentistry, Palacky University, Olomouc, Czech Republic 3 NATUREX-DBS, 375 Huyler Street, South Hackensack, NJ, USA 4 NATUREX SA, 250 Rue Pierre Bayle, 84911 Avignon, France