Can beta-sitosterol be used to cure BHP?
BACKGROUND
Beta-sitosterol is one of several phytosterols or plant products that are chemically similar to cholesterol. It is sometimes used by those with high cholesterol levels, as is sitostanol, a different, though related compound. Beta-sitosterol is also recommended for benign prostatic hyperplasia (BPH), which will be the focus here.
BPH is a relatively common condition among older men where the prostate gland enlarges and causes lower urinary tract symptoms (LUTS). These include frequent desires to urinate (especially at night), difficulty urinating and a weak flow of urine.
BPH symptoms range from being irritating or embarrassing to where they can be painful or lead to serious problems. BPH is not a form of cancer, although sometimes men with BPH also develop prostate cancer.
Conventional medications are available for BPH, but can have adverse effects. For this reason, the use of herbal remedies for BPH has been increasing. In Germany, more than 90 per cent of prescriptions for BPH are for herbal remedies, while in Italy it is about 50 per cent. The most popular herbal remedy for BPH has been saw palmetto, although the most recent research has been shedding doubt on its effectiveness.
The results of the long-awaited CAMUS trial were published in September 2011. This large, controlled trial found no benefits for men with BPH taking saw palmetto beyond the placebo effect. The study lasted 17 months with the men taking either the standard dose, or double or triple that dose. No differences were found between the different doses. Other herbs for BPH are being considered, with beta-sitosterol to the fore.
EVIDENCE FROM STUDIES
A small number of controlled studies have been conducted using beta-sitosterol. Most of these used extracts made from a number of different plants. The majority of the randomised, placebo-controlled studies showed significant improvements in urinary symptoms. No significant changes were reported for the size of the prostate.
However, one study used pure beta-sitosterol and found no significant benefits. This has raised questions regarding whether beta-sitosterol is the active ingredient or whether some other component of the extracts is having an effect.
The total number of studies conducted remains small, and they enrolled small numbers of men. The studies had a number of other limitations. None of them lasted longer than six months, which means that the long-term safety and effectiveness has not been determined.
One study did follow up with its participants 18 months after the trial finished. Those men who continued to use beta-sitosterol reported that their symptoms remained stable, while those who discontinued beta-sitosterol had slightly worsened symptoms.
However, this part of the study was not controlled and the results could have been due to many other factors. None of the studies identified compared beta-sitosterol directly against any conventional medications.
PROBLEMATIC ASPECTS
Beta-sitosterol is generally safe and is added to some margarines to help with cholesterol reduction. However, beta-sitosterol capsules sometimes cause gastrointestinal problems such as nausea, indigestion or diarrhoea.
RECOMMENDATIONS
Beta-sitosterol has some evidence to support its effectiveness against BPH. However, the studies are small in number and size. They have also been conducted for relatively short lengths of time, which is an important limitation given that BPH is a chronic condition.
Given this limited evidence, a trial period with beta-sitosterol could be helpful, especially for those with mild symptoms or who do not react well to conventional medications. Beta-sitosterol is safe and may have some additional benefits in preventing the absorption of cholesterol from the diet.
Beta-sitosterol is found in numerous plants, leading to many different products made from different plants and containing different amounts of beta-sitosterol. The optimal dose has not been determined.
Dónal OMathúna has a PhD in pharmacy, researching herbal remedies, and an MA in bioethics, and is a senior lecturer in the School of Nursing Human Sciences, DCU.
