Studies show moderate alcohol intake has surprising links to prostate disease.
Dr. Parsons is professor of urology, division of urologic oncology, department of urology, Moores UCSD Comprehensive Cancer Center, La Jolla, CA.
Patients have become voracious consumers of the medical literature. Each week, a flurry of new urology studies surface in the popular media to feed public interest. Many of the high-profile articles focus on prostate disease and lifestyle factors. Popular topics include associations of prostate cancer and BPH with diet, exercise, vitamins, and supplements. Many present contradictory results; all have the potential to provoke anxiety and/or confusion among our patients.
A recurring topic is alcohol. Excessive alcohol consumption is, of course, unhealthy and should be discouraged. But what about moderate alcohol intake, such as a glass of red wine each day? Is moderate alcohol intake beneficial or harmful to the prostate, or neither?
Numerous observational studies have addressed this question with respect to prostate cancer, BPH, and lower urinary tract symptoms (LUTS). Here are some take-aways (summarized in the table).
For prostate cancer, the answer appears to be: neither.
A large number of studies and several meta-analyses have failed to turn up any consistent patterns of moderate alcohol consumption with prostate cancer risk. While some studies have observed dose-dependent, modestly increased risks of incident disease (BMC Cancer 2016; 16:845; Int J Cancer 2014; 134:971-8), others have not (Cancer Epidemiol Biomarkers Prev 2008; 17:1282-7). Still others have arrived at mixed results. For example, a meta-analysis of 17 observational studies (611,169 participants) concluded that, while there were no overall associations between wine intake with prostate cancer, moderate white wine consumption increased while red wine decreased incident cancer risk (Clinical Epidemiology 2018; 10:431-44).
Keeping with the theme of red wine, patients may ask about resveratrol, a polyphenolic, antioxidant compound found in red wine and grape skin. Despite some pre-clinical in vitroand animal studies suggesting antineoplastic activity, there are no conclusive clinical data to demonstrate resveratrol prevents or protects against prostate cancer.
How does moderate alcohol intake impact BPH? Research shows it appears to be beneficial.
Individual studies and meta-analyses have observed that moderate alcohol intake appears to prevent incident BPH. Definitions of BPH in these studies included radiologic enlargement, decreased urinary flow rates, urodynamic studies consistent with bladder outlet obstruction, incidence of BPH surgery, acute urinary retention, physician-diagnosed BPH, LUTS, and histologic diagnosis. In a meta-analysis of 19 studies that incorporated 120,091 men, alcohol intake ≥36 g/day was associated with a 35% decreased likelihood of BPH (J Urol 2009; 182:1463-8).
On its face, this concept would appear counterintuitive. Alcohol is a potent diuretic with the potential to provoke symptoms associated with bladder outlet obstruction. Yet moderate alcohol intake has also been associated with a decreased risk of cardiovascular disease. Because obesity, metabolic syndrome, and cardiovascular disease increase the risk of BPH, a potential explanation is that alcohol positively modulates the phenotypic expression of BPH through beneficial effects on shared metabolic perturbations linked to cardiovascular health.
Finally, for LUTS, the answer to whether alcohol intake is beneficial or harmful appears to be: possibly beneficial.
LUTS, rather than BPH, has become the preferred term for describing urinary symptoms in male populations. The most commonly used measures are the AUA Symptom Index and the International Prostate Symptom Score.
Observational studies have demonstrated both positive and negative effects of alcohol on LUTS, with a slight preponderance of studies favoring a positive effect (J Urol 2017; 198:1010-20). The relationship is complex, and perhaps the most robust way of describing it is through a so-called “J” curve, with LUTS severity (or LUTS probability) plotted on the y-axis and alcohol intake on the x-axis. In this model, low to moderate alcohol decreases LUTS risk, but increased amounts of alcohol increase LUTS in a dose-dependent manner (J Urol 2012; 187:1312-7).
Still, clinical judgment in individual cases should prevail. Reduction of alcohol intake in men with storage-predominant LUTS or primary nocturia, for example, is a simple and often efficacious approach to reducing symptoms.
Epidemiologic evidence suggests that alcohol intake is linked to prostate disease in surprising and beneficial ways, with moderate consumption associated with decreased risks of both BPH and LUTS. Alcohol appears to have no substantive effects on prostate cancer risk. Patients should be counseled, as with other lifestyle factors such as diet and exercise, to practice moderation when considering these data.
Section Editor Steven A. Kaplan, MD, is professor of urology, Icahn School of Medicine at Mount Sinai, New York.