Even though benign prostatic hyperplasia (BPH) is one of the most common diseases of aging men, its cause remains relatively unknown. From our current understanding, BPH appears to be related to age, levels of a form of testosterone called dihydrotestosterone (DHT), and estrogen. DHT inhibits prostatic cell death, promotes cell proliferation, and thus increases the size of the prostate. As a man passes his fifth decade of life, serum testosterone levels decrease and estrogen levels rise. Estrogen increases the number of DHT receptors in the prostate as well as the circulating levels of DHT.
Components of metabolic syndrome have also been shown to cause prostate enlargement with insulin resistance (and thus increased insulin levels) and truncal obesity being the main culprits.1 Insulin binds to insulin-like growth factor (IGF) receptors which stimulates prostate cell growth.2 Excess amount of visceral fat is also a contributing factor in the increase in circulating levels of estradiol which leads to increased levels of DHT and further prostate enlargement. 3
Soy is thought to work in two ways. It’s an inhibitor of 5-alpha-reductase and also a low-potency estrogen. Soy may block receptor sites that estrogens use to increase DHT levels. Consumption of nonfermented soy products (tofu, soy milk, edamame) has been found to decrease incidence of prostate cancer.4 A diet rich in omega-3 fatty acids helps reduce the influence of prostaglandins and leukotrienes on the inflammatory component of BPH.
Intestinal uptake of zinc is inhibited by estrogen. Because aging men have increased estrogen levels, men with BPH may have low zinc levels. In the 1970s, research showed that supplementing with zinc resulted in a reduction in the size of the prostate and in symptoms of BPH.5 Further research showed that zinc inhibits an enzyme called 5-alpha-reductase which produces DHT,6 and also inhibits the binding of DHT to its receptors in the prostate.7 Therefore, zinc not only decreases the production of DHT but also inhibits DHT binding to its receptors.
Finally, saw palmetto has been found to be a weak inhibitor of 5-alpha-reductase, but it may have a more active role in reducing the number of estrogen and DHT receptors, as well as an antiinflammatory effect on the prostate.
At RMRM, we know there isn’t a one-size-fits-all solution to wellness and therefore individualize our approach to problems such as BPH based on each specific situation.
- J. Hammarsten, B. Hogstedt, N. Holthuis, D. Mellstrom: Components of the metabolic syndrome—risk factors for the development of benign prostatic hyperplasia. Prostate Cancer Prostatic Dis. 1:157-162 1998
- S. Rohrmann, E. Smit, E. Giovannucci, E.A. Platz: Association between markers of the metabolic syndrome and lower urinary tract symptoms in the Third National and Nutrition Examination Survey (NHANES III). Int J Obes Relat Metab Disord. 29:310-316 2004
- J.C. Nickel, C.G. Roehrborn, M.P. O’Leary, et al.: The relationship between prostate inflammation and lower urinary tract symptoms: examination of baseline data from the REDUCE trial. Eur Urol. 54:1379-1384 2008
- J.M. Chan, P.H. Gann, E.L. Giovannucci: Role of diet in prostate cancer development and progression. J Clin Oncol. 23:8152-8160 2005
- M. Fahim, Z. Fahim, R. Der, J. Harman: Zinc treatment for the reduction of hyperplasia of the prostate. Fed Proc. 35:361 1976
- A. Leake, G.D. Chisholm, F.K. Habib: The effect of zinc on the 5-α-reduction of testosterone by the hyperplastic human prostate gland. J Steroid Biochem. 20:651-6551984
- A. Leake, G.D. Chisholm, A. Busuttil, F.K. Habib: Subcellular distribution of zinc in the benign and malignant human prostate: evidence for a direct zinc androgen interaction. Acta Endocrinol. 105:281-288 1984