Prostate gland enlargement

Townsend Letter for Doctors and Patients, May, 2006 by Martin W. Banschbach

Vitamin E appears to work just as it does in other tissues. Lycopene is actually concentrated in the prostate gland. Lycopene probably works as a general antioxidant, but it may also play a unique role in the prostate gland. Lycopene can specifically interfere with the mitogenic activity of insulin-like growth factor one (IGF-I). (12) Mitogenic refers to the ability to make cells divide. Cells in the transition zone of the prostate divide, and this leads to an increase in the size of the gland. Lycopene may have a role in decreasing this expansion of the prostate gland if IGF-I is involved in promoting this cell division. A more recent review of the dietary factors thought to play a role in prostate cancer shows that lycopene and the phytoestrogens are still considered to be important dietary factors in the prevention of prostate cancer. (13)

Prostate-Specific Nutrients: The fluid produced by the prostate gland is very high in zinc. The prostate gland actually contains a higher level of zinc than any other gland or tissue in the human body. This high zinc level appears to be needed to produce high levels of citric acid in human prostate fluid. (14) This citric acid may be used as a fuel by human sperm. Since too much iodine in the thyroid gland can make that gland expand in size, it's also thought that too much zinc in the prostate gland might make this gland expand in size. Epidemiology data does suggest that, as the dietary intake of zinc increases, the risk of BPH also increases. (15) Zinc levels in the human prostate gland have been measured in several human studies, and most of these studies show that BPH is associated with increased zinc levels in the prostate gland itself. (16) The increase seen in one study (Zaichick, et al.) is similar to that seen in other similar studies that have been conducted. Normal was 1,018 micrograms per gram of dry prostate tissue versus 1,142 micrograms per gram of dry prostate tissue in patients with benign prostatic hyperplasia.

However, zinc may just be a marker for cadmium intake. (Epidemiology data showing an increase in dietary zinc may have been marking cadmium intake, rather than zinc, in relationship to prostate gland enlargement.) Cadmium levels are known to be elevated in BPH. (17) Cadmium is now thought to be an important dietary factor in human prostate cancer risk. (18) In castrated animals, a single low dose of cadmium (20 micrograms per kilogram body weight) increases the wet weight of the prostate gland by 1.97 to three-fold. (19)

Cadmium and zinc are very similar in terms of chemical and biologic properties. Both minerals bind to metallothionein, and both compete for absorption in the small intestine. Most of the toxic effects of cadmium appear to be due to its interference with zinc. Since cadmium has a biological half-life in humans of about 20 years, the best way to try to prevent a problem with cadmium in the first place is to have plenty of zinc present in the diet. (20) This extensive review of what cadmium can do in humans points out that humans with the poorest zinc status display the most severe cadmium toxicity. Cadmium can also come in through the lungs from breathing in dust laden with cadmium (occupational exposure) or smoking.