Saw palmetto's therapeutic uses
Saw palmetto, derived from the berries of the Serenoa repens palm, is primarily recognized for its therapeutic uses in treating benign prostatic hyperplasia (BPH), a condition that leads to urinary difficulties in men. Traditionally used by Native Americans for various urinary issues, modern applications include managing symptoms of BPH such as weak urine flow and frequent urination. Research suggests that saw palmetto may improve these symptoms and potentially delay prostate enlargement over time, with a typical dosage of 160 mg twice daily or a single dose of 320 mg.
In addition to BPH, saw palmetto is sometimes recommended for hair loss and prostatitis, although evidence regarding its effectiveness for these conditions is mixed. While it is viewed as a safer alternative to some pharmaceutical treatments, such as Proscar, which can lower prostate-specific antigen (PSA) levels, saw palmetto does not appear to have the same impact on PSA and may cause fewer side effects. Despite its generally regarded safety, individuals should consult healthcare providers prior to use, especially if pregnant, nursing, or taking medications that affect blood coagulation. Overall, while saw palmetto shows promise for certain therapeutic applications, further research is needed to fully understand its potential benefits and safety profile.
Saw palmetto's therapeutic uses
- PRINCIPAL PROPOSED USE: Benign prostatic hyperplasia (BPH)
- OTHER PROPOSED USES: Hair loss, prostatitis
DEFINITION: Natural plant product used to treat specific health conditions
Overview
Saw palmetto (Serenoa repens, Serenoa serrulata, Sabal serrulata), sometimes called the American dwarf palm tree or the cabbage palm, is a native palm tree of North America, and it is still primarily grown in the United States. The saw palmetto tree grows to a height of 4 to 10 feet; it has fan-shaped serrated leaves and abundant berries. Native Americans used these berries for the treatment of various urinary problems in men, as well as for women with breast disorders. European and American physicians took up saw palmetto as a treatment for benign prostatic hyperplasia (BPH). In the 1960s, French researchers discovered that concentrating saw palmetto berry oils, they could maximize the herb’s effectiveness.
Saw palmetto contains many biologically active chemicals. It is unknown which of these chemicals is the most important. It is also not known precisely how saw palmetto works, as the herb appears to interact with various sex hormones, but also has many other complex actions that could affect the prostate.
Therapeutic Dosages
The standard dosage of saw palmetto for treating BPH is 160 milligrams (mg) twice a day of an extract standardized to contain 85 to 95 percent fatty acids and sterols. A single daily dose of 320 mg may be just as effective for this condition. However, taking more than this amount does not, on average, seem to produce better results.
As with many herbs, the quality of commercial saw palmetto products may vary widely. For this reason, it is recommended that individuals purchase only saw palmetto products that have been evaluated by an independent laboratory. Saw palmetto is available in tablets and a topical oil or lotion.
Therapeutic Uses
Saw palmetto oil is an accepted medical treatment for BPH in New Zealand and in France, Germany, Austria, Italy, Spain, and other European countries. Typical symptoms of BPH include difficulty starting urination, weak urinary stream, frequent urination, dribbling after urination, and waking up several times at night to urinate. Most research suggests that saw palmetto can markedly improve all these symptoms. Benefits require approximately four to six weeks of treatment to develop, but about two-thirds of men respond reasonably well.
Furthermore, while the prostate tends to continue to grow when left untreated, saw palmetto causes a small but definite shrinkage. In other words, it appears that it does not just relieve symptoms but actually delays prostate enlargement. The drug Proscar does this too (and to a greater extent than saw palmetto), but other standard medications for BPH have no effect on prostate size.
Some studies suggest that saw palmetto is just as effective for reducing BPH symptoms as Proscar, and it has one meaningful advantage: It leaves prostate-specific antigen (PSA) levels unchanged. Cancer raises PSA levels, and lab tests that measure PSA are used to screen for prostate cancer. Proscar lowers PSA measurements, and therefore, its use may have the unintended effect of masking prostate cancer. Saw palmetto does not do this. On the other hand, Proscar has been shown to reduce the need for surgery, unlike saw palmetto or any of the other drugs used for BPH. Saw palmetto may also be just as effective as another class of standard drugs known as alpha-blockers and may cause fewer side effects. Individuals should not self-treat with saw palmetto without first undergoing a proper medical evaluation to rule out prostate cancer.
Saw palmetto is also widely used to treat chronic prostatitis. An open trial that compared saw palmetto to the drug Proscar for the treatment of chronic nonbacterial prostatitis found that while the drug was effective, the herb was not. However, these results do not mean that saw palmetto is ineffective for prostatitis. Because this was an open study, researchers and participants knew who was getting saw palmetto and who was getting the drug. If there was any expectation that the drug would be more powerful than the herb, this in itself would have been sufficient to skew the results toward that outcome.
Several other uses have been proposed. Saw palmetto is sometimes recommended as a treatment for hair loss and for use in individuals with alopecia. Saw palmetto may be useful in improving patient outcomes in some prostate surgeries. Men who took 320 mg supplements for two months before transurethral resection of the prostate (TURP surgery) experienced better healing and less pain.
Scientific Evidence
The scientific evidence for the effectiveness of saw palmetto in treating prostate enlargement is inconsistent. A minimum of twelve double-blind studies involving a total of about nine hundred people have compared the benefits of saw palmetto against placebo over periods of one to twelve months. In all but three of these studies, the herb improved urinary flow rate and most other measures of prostate disease to a greater extent than did placebo. However, in the most recent and perhaps best designed of these studies, a one-year trial of 225 men, a saw palmetto product failed to prove more effective than placebo. Furthermore, a large review of fourteen trials with 5,222 men found that saw palmetto did not improve urinary symptom scores or peak urine flow compared with placebo. Subjects taking saw palmetto reported more overall symptom improvement than those taking placebo, but this result is questionable owing to inconsistencies among studies.
A double-blind study followed 1,098 men who received either saw palmetto or the drug Proscar for six monthshe study had no placebo group. The treatments were equally effective, but while Proscar lowered PSA levels and caused a slight worsening of sexual function on average, saw palmetto caused no significant side effects. Both treatments caused the prostate to shrink, but Proscar had a greater effect.
A fifty-two-week double-blind study of 811 men compared saw palmetto to a standard drug in another class: the alpha-blocker tamsulosin. Once again, both treatments proved equally effective. However, saw palmetto caused fewer side effects than the drug. In addition, the herb caused some prostate shrinkage, while the drug caused a slight prostate enlargement.
A study involving 435 men found the benefits of saw palmetto endure for at least three years. However, there was no control group in this study, making the results unreliable.
A forty-eight-week double-blind trial of 543 men with early BPH compared combined saw palmetto and nettle root against Proscar and found equal benefits. Benefits were also seen with a combination of saw palmetto and nettle root in a twenty-four-week placebo-controlled study of 257 men.
A six-month double-blind, placebo-controlled trial of 44 men given a saw palmetto herbal blend (containing, in addition, nettle root and pumpkin seed oil) found shrinkage in prostate tissue. No significant improvement in symptoms was seen, but the researchers pointed out that the study size was too small to statistically detect such improvements if they did occur.
In a sixteen-week placebo-controlled, randomized study, researchers found positive results in using saw palmetto for individuals with mild to moderate androgenetic alopecia (AGA). Eighty participants between eighteen and fifty used a standardized saw palmetto oil of 2 to 3 percent β-sitosterol called VISPO as an oral or topical treatment. Compared to the placebo group, those who received the topical treatment experienced a 7.6 percent increase in hair density, while those who took the oral form of VISPO experienced a 5.17 percent increase. Further research is needed, but several similar studies reported findings that support saw palmetto’s use for hair loss.
Safety Issues
Saw palmetto is thought to be essentially nontoxic. It is safe in large doses for up to three years when taken orally. In clinical trials, it has shown little to no adverse effect. For example, in a one-year randomized trial of 225 men, there was no significant difference in adverse events between the group receiving saw palmetto and the group receiving placebo. Also, in a three-year study, only 34 of the 435 participants had side effects, and these were primarily only of the usual nonspecific variety seen with all medications, such as mild gastrointestinal distress.
There are at least two case reports in which the use of saw palmetto was linked to liver inflammation. However, a subsequent study in rats failed to find that even very high doses of saw palmetto are injurious to the liver. This case report might have been an instance of an allergic or other idiosyncratic reaction. Alternatively, something other than saw palmetto may have gotten into the product. One of the above-mentioned cases also involved pancreatitis.
Finally, one case report indicated that saw palmetto caused excessive bleeding during surgery. The significance of this isolated event is unclear, but it is probably prudent for individuals to avoid saw palmetto prior to and just after surgery, as well as during the period surrounding labor and delivery. Individuals with bleeding problemssuch as hemophiliashould perhaps also avoid saw palmetto, as should those taking any drug that thins the blood, such as warfarin (Coumadin), heparin, aspirin, clopidogrel (Plavix), ticlopidine (Ticlid), or pentoxifylline (Trental). Saw palmetto may interfere with the amount of estrogen in the body, which may negatively impact individuals taking estrogen pills or oral contraceptives that contain estrogen.
Saw palmetto is not safe for pregnant or nursing women because of its impact on hormones. Safety for those with severe kidney or liver disease has not been established.
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