Saw Palmetto May Not Reduce BPH Symptoms

Contrary to previous research, a new study suggests that saw palmetto extract may not reduce urinary tract symptoms associated with benign prostatic hyperplasia (BPH) more than placebo.

Saw palmetto is popularly used throughout Europe to treat symptoms associated with BPH (enlarged prostate). It is also the most popularly used herbal supplement for this condition in the United States. Many human trials have reported that saw palmetto improved symptoms associated with BPH, such as nighttime urination and urinary flow. Although some trials have reported no difference between the effects of saw palmetto and placebo, in general, the scientific evidence favors the effectiveness of saw palmetto over placebo.

In a recent study, researchers randomly assigned 369 men with BPH to increasing doses of saw palmetto or placebo for 72 weeks. Treatment doses started at 320 milligrams of saw palmetto daily, then at 24 weeks increased to two doses of 320 milligrams daily, and finally at 48 weeks increased to three doses of 320 milligrams daily.

Before inclusion in the study, the men went through two screening sessions. Individuals ultimately included had at least a peak urinary flow rate of 4 milliliters per second and an American Urological Association Symptom Index (AUASI) score between 8 and 24. The change in the AUASI score was used as the main outcome measure.

Contrary to previous findings, the researchers found that the men in the placebo group had a greater average decrease in AUASI scores than the men in the saw palmetto group. AUASI scores in the placebo group decreased from 14.69 to 11.70, while the average decrease in the saw palmetto group was slightly less from 14.42 to 12.22. Furthermore, there were no notable differences in changes for secondary outcome measures, including sleep quality and peak urine flow.

The authors concluded that contrary to previous findings, saw palmetto may not reduce urinary tract symptoms associated with BPH more than placebo. Further research is necessary.

For more information on integrative therapies with evidence of benefit for BPH, such as pygeum and plant sterols, please vist Natural Standard's Comparative Effectiveness Database.

For more information about saw palmetto, please visit Natural Standard's Foods, Herbs & Supplements Database.

Comments

[M Allen]

I would like to see the standardization methods used in this study, if there were any. It would be interesting to see if a new study were to be conducted with a larger sample size, and possibly compare saw palmetto to a conventional treatment such as finasteride as well as placebo. I too have always recommended this alternative therapy to patients, but now I have conflicting reports.

[Shannon]

As others have mentioned, I also have recommended saw palmetto as a option for patients who prefer to not use the limited number of prescription medications for BPH. After reading this, I will have to tell future patients that data is conflicting. That in a study conducted recently, it showed less of a decrease in symptoms than placebo. It’s unfortunate that the natural agent that one typically thinks of for treating BPH might not be effective. Also so many men are affected by BPH, who all have different preferences for different treatment agents. So, limiting the number of agents is never a good thing when pharmacist like to provide their patients with different options for treatment.

[NK]

I read that BPH is a condition that up to 50% of men over the age of 50 will deal with in some form or fashion. That being the case, it’s important that men have their prostate examined at least yearly or if experiencing signs and symptoms of BPH. In some cases, drug therapy may not help relieve these symptoms so there are procedures that are available. One of these is called a transurethral resection of the prostate (TURP), a surgical procedure where prostate tissue blocking urine flow is removed. Although BPH is common, there are many options available. Always explore all options!

[Steph Zabel]

I am also surprised at the findings of this study. I'd like to know more about the brand and quality of the saw palmetto that was given, as well as the extraction method of the berries. When it comes to herbs there can be such a huge range of quality in the original plant material - and therefore efficacy can be compromised. Not all herbal supplements are created equally.

[NK]

Something interesting about saw palmetto is that it contains tannins. Tannins are molecules that bind and form complexes with proteins in the body and, therefore, may prevent the absorption of iron in the body. For people with chronic anemia, saw palmetto may exacerbate this condition and should be used with caution. Another thing to consider is if someone has acute iron deficiency and is taking saw palmetto, this may be the reason.

[SA]

The study results are another conformation of STEP1 trial which was the largest trial in that field and showed no improvement over placebo in a one year period at dose of 160 mg twice daily. This study used doses higher than STEP trial to assess if higher doses are effective in managing BPH symptoms.
1- Bent S, Kane C, Shinohara K, et al. Saw palmetto for benign prostatic hyperplasia. N Engl J Med. 2006;354(6):557-566.

[Anonymous]

I was very surprised to see the outcomes of this study. One thing that comes to mind when seeing this is what was different in the numerous previous studies done that showed that saw palmetto was effective for helping with BPH symptoms? Did this study use a different extraction method, etc than the previous studies did? I am looking forward to how the outcomes of further studies will be compared to this one.

[MK]

The results of this study are shocking. I have always believed that saw palmetto had beneficial effects in benign prostatic hyperplasia (BPH). A couple of years ago, we had an intern pharmacist at my pharmacy that had done research on this and had found that in fact saw palmetto did provide positive effects in BPH. This is too bad as I recommend saw palmetto to many of my own patients/customers. Perhaps the particular brand of saw palmetto that was used in this study was not effective. I hope to see further studies on this topic.

[NK]

It seems that this trial has shown that saw palmetto is not superior to no treatment at all, which is very interesting since it is one of the most common alternative therapies used in the treatment of BPH. Based on the results reported in the abstract, it even seems that no treatment at all had a better overall outcome than the saw palmetto treatment group. Saw palmetto may also have anti-androgenic activity and therefore, some use it for the treatment of alopecia (hair loss).