Efficacy and Safety of a Flaxseed Hull Extract in the Symptomatic Management of Benign Prostatic Hyperplasia: A Parallel, Randomized, Double-Blind, Placebo-Controlled, Pilot Study.

Key Findings:

The flaxseed lignan secoisolariciresinol diglucoside was assessed for the treatment of benign prostatic hyperplasia (BPH). This study was a randomized, double-blind and placebo-controlled. The results showed the efficacy and safety of two dosages (low and high) of a lignan-rich flaxseed extract, LinumLife EXTRA for the improvement of BPH. The flaxseed hull extract provided greater relief than placebo in obstructive symptoms of BPH, such as sensation of incomplete bladder emptying, “stopping and starting” while urinating, weak urinary stream, and “straining while urinating.”  Low and high doses of the flaxseed extract provided statistically significant improvements in the scores of these symptoms at week 8 as compared with baseline.  Flaxseed feeding led to a significant improvement of the serum DHT levels, a known biomarker for BPH.  There was however a significant placebo effect. The study showed that a standardized flaxseed extract equivalent of up to 200 mg SDG is safe for human use and leads to no adverse effects.

ABSTRACT:

This exploratory study was designed to assess the effectiveness of a lignan-rich extract of flaxseed hulls in alleviating symptoms in subjects with benign prostatic hyperplasia (BPH) compared with a placebo. Two dosages of extract were compared against placebo in a double-blinded, randomized, parallel, multicenter study.  Newly diagnosed cases of BPH in patients aged 45 – 75 years with an American Urological Association Symptom Index score of less than or equal to 13 were included.  Study treatment consisted of 500 or 100 mg  (low-dose active)of extract containing 100 mg group or 200 mg (high-dose active) group of secoisolariciresinol diglucoside (SDG), respectively.  The placebo group received matching maltodextrin capsules.  Sixty subjects, HDA and P completed the study as per the protocol requirements.  Change in the AUASI score within a period of 8 weeks, from baseline to end of treatment, was assessed.  Significant Improvement of obstructive symptoms and management of irritable BPH symptoms was achieved in all groups after treatment.  Due to a strong placebo effect, there was no statistical difference between the groups that were treated with flaxseed hull extract as compared with the placebo group.  Treatment with flaxseed hull extract did not lead to adverse effects compared with placebo.  Supplementation with flaxseed hull extract was found to be safe and well-tolerated and may have improved the quality of life of individuals with BPH.  The significant placebo effect as well as the number of subjects per treatment group and the relative short duration of the study may explain the lack of statistical significance between groups. (Authors abstract)