For PROSTATE ENLARGEMENT, saw palmetto concentrate reduces overgrowth of prostate cells, improves urine stream, and lessens nocturnal urination. It does this by reducing prolonged exposure to the strong androgen dihydrotestosterone (DHT), a potent breakdown product of testosterone which can lead to benign hypertrophy or overgrowth of prostate tissue, also known as BPH. Saw palmetto also slows excessive growth of prostate epithelium cells that line the gland’s ducts.
The prostate gland secretes fluids to maintain an optimal semen environment to support healthy sperm production. Prostate tissues naturally have a very high concentration of androgens for this process, mostly testosterone. But research indicates that prolonged exposure to DHT, a stronger androgen that results from testosterone breakdown, is responsible for the overgrowth of prostate cells.
For benign prostatic hyperplasia (BPH), saw palmetto (S repens) is a powerful adaptogen which functions naturally to regulate the male endocrine system function. Adaptogenic herbs like saw palmetto have the unique ability to “adapt” their actions, either boosting or calming physiological functions, according to the body’s specific needs.
Saw palmetto, also known as the American dwarf palm tree, is a tree native to the West Indies and the southeast coast of North America. It grows to a height of 6 to 10 feet and is characterized by thorn-shaped leaves that are arranged like a fan. The berries, which are maroon colored and oblong shaped, have been used for more than a hundred years for prostate symptoms. It is now one of the most widely used botanicals in the world, by over two million men in the U.S. alone. Saw palmetto has a strong track record, with roughly 90% of men getting relief for mild to moderate prostate symptoms. As with prescriptions, it may not work as well for advanced BPH. In Germany, Austria, and Italy, saw palmetto is used as a first-line treatment for prostate gland enlargement. Its extract is believed to be a highly effective androgen stabilizer as it contains phytosterols. Saw palmetto’s action is enhanced by pygeum and nettle root.
Research trials verify that saw palmetto inhibits 5-alpha-reductase activity on testosterone in vitro, preventing the conversion of testosterone to DHT. One open, randomized, placebo-controlled study indicated that saw palmetto may reduce DHT levels in the plasma. A 2004 review published in The Journal of Urology that analyzed 30 in vivo and in vitro laboratory studies, noted that the frequency of use of saw palmetto globally for medical treatment of BPH matches the use of conventional drugs. The studies indicate that saw palmetto has a wide spectrum of activity and works via numerous mechanisms of action. These include an antiandrogenic effect, subduing excess testosterone and DHT, and an anti-inflammatory action. Also saw palmetto was shown to have an antiproliferative influence through the inhibition of growth factors, slowing the overgrowth of prostate tissue. Although the precise mechanisms of action are still being studied and clarified, given the current knowledge of the physiology of the aging prostate, the review concludes that saw palmetto – especially in combination with pygeum – is clearly effective. It is licensed and used widely throughout Europe for symptomatic BPH.2
Saw palmetto works in at least six important ways:
- Saw palmetto helps to decrease symptoms of hyperandrogenism, or elevated testosterone levels, by impeding the enzyme 5-alpha-reductase, which produces DHT. Dihydrotestosterone, or DHT, is a very strong breakdown product of testosterone, which can over-stimulate prostate tissue. Saw palmetto also appears to decrease DHT uptake by hair follicles, which may help with reported hair loss by blocking the binding of DHT to androgen receptors.1 Studies have verified that saw palmetto inhibits 5-alpha-reductase activity on testosterone in vitro, preventing the conversion of testosterone to DHT and possibly protecting prostate cells from tumor risk.
- Saw palmetto is effective at preventing DHT from attaching to prostate cells. This means that any DHT that happens to be around prostate tissue has less opportunity to stimulate prostate cell overgrowth.
- In addition, saw palmetto speeds the breakdown and removal of DHT, so that less of it is in the vicinity of prostate tissue. Saw palmetto also helps in several ways to clear androgens from the body.
- Saw palmetto also binds up excess androgen hormones including testosterone and estrogen in the body, tying them up so they are unavailable to influence the prostate. Other actions of saw palmetto include distributing these hormones to their correct locations at the right times when they are needed.
- Saw palmetto has been found in research to slow overgrowth of prostate lining cells, the epithelium. Contraction of the epithelium encourages the prostate to shrink. With less prostate tissue pressure on the bladder and urethra, a man can enjoy better urine flow. Studies showed that saw palmetto’s action to shrink the prostate epithelium happens independently of its effects on testosterone or DHT, by direct non-hormonal action on prostate tissue.
- Saw palmetto also eases BPH by reducing inflammation. As fewer inflammation-triggering mast cells aggregate, and the levels of inflammatory mediators including lipoxygenase and cyclooxygenase drop, then prostate swelling is reduced. When an enlarged prostate shrinks, then urinary volume improves; urinary frequency, nocturnal urination, and bladder discomfort lessen; and sometimes PSA levels drop.
Numerous clinical studies with thousands of men have documented saw palmetto’s efficacy for up to 90% of subjects with mild or moderate BPH. The benefits of saw palmetto can build over time: men taking saw palmetto over two years were checked at six, twelve and 24 months and at each stage their quality of life and urinary function improved more while prostate size and symptoms continued to decrease. They found that sexual function was unchanged for the first year and then significantly improved during the second year. Compare this to the drug finasteride (Proscar) which causes erectile dysfunction for about 5% of users. A New England Journal of Medicine report suggested that saw palmetto may be less effective for BPH that was too advanced to be helped by prescription therapy.
Other studies used the International Prostate Symptom Score (IPSS) and measurements of urinary flow rate. The IPSS is an eight-question, self-administered screening tool used by patients to track their symptoms, including: feeling of incomplete bladder emptying, frequency of urination, intermittency of urine stream, urgency of urination, weak stream, straining, and waking at night to urinate. Men with moderate BPH randomly received saw palmetto or placebo: the herb groups had significant decreases in prostate symptom scores and increases in quality-of-life scores. Saw palmetto is also being used for hormone restoration in anti-aging medicine in place of testosterone, which can elevate DHT. Together with zinc, saw palmetto can safely help to balance testosterone, pregnenolone, dehydroepiandrosterone (DHEA), progesterone, cortisol, and estrogen. In addition, saw palmetto has a role in reversing hair loss, for women and maybe for men too, by binding up excessive DHT in the scalp. Research is finding that after six months on saw palmetto, 60% of subjects have improvement according to standardized scales of hair assessment and their own opinions. The drug finasteride can also relieve hair loss but cause erectile dysfunction and loss of libido.
A systematic review of over 30 years of studies on saw palmetto extract for treatment of BPH looked at 18 randomized controlled trials involving a total of 2939 men. It concluded that “evidence suggests that Serenoa repens, the botanical name for saw palmetto, improves urologic symptoms and flow measures. Compared with finasteride, S repens produces similar improvement in urinary tract symptoms and urinary flow and was associated with fewer adverse treatment events.”1
Studies involving in vitro research with serenoa extracts found that saw palmetto inhibits 5-alpha-reductase activity, in both of its forms, isoenzyme I and II. A modest but significant decline in prostate DHT levels was observed after six months of a placebo-controlled trial involving 40 men. Di Silvero and colleagues found that saw palmetto decreased epidermal growth factor, which they associated with DHT suppression in prostatic tissue of patients.3
In our clinic, we look for a minimum of 144mg of saw palmetto sterols daily, (160mg at 90%, or 320mg at 45%). This regularly offers our patients ongoing improvements with less getting up at night, good urination stream, improved bladder emptying, and reduced urgency. Overall we see significantly better results if pygeum and nettle root are added, which magnify the benefits of saw palmetto. Stinging Nettle modulates androgen receptors and inhibits enzymes to effectively treat symptoms of excess testosterone. Pygeum (Prunus africana) Bark Extract has hormone-balancing effects and also inhibits 5-alpha reductase so that less DHT is made in prostate cells. Pollen concentrate has powerful anti-inflammatory benefits, and it encourages the bladder muscles to contract efficiently while relaxing the urethra.
Recommendations: Saw Palmetto 320mg standardized to >45% total sterols, or 160mg at 90%, once or twice daily, best absorbed between meals, or as directed by your healthcare provider.
- Wilt, Timothy J., et al. “Saw palmetto extracts for treatment of benign prostatic hyperplasia: a systematic review.” Jama 280.18 (1998): 1604-1609.
- Buck, A. C. “Is there a scientific basis for the therapeutic effects of serenoa repens in benign prostatic hyperplasia? Mechanisms of action.” The Journal of urology 172.5 (2004): 1792-1799.
- Di Silverio, F., et al. “Effects of long‐term treatment with Serenoa repens (Permixon®) on the concentrations and regional distribution of androgens and epidermal growth factor in benign prostatic hyperplasia.” The Prostate 37.2 (1998): 77-