Saw palmetto (Serenoa repens) is a small palm native to the south-eastern United States which grows to about 2-3 metres with leaf fans comprised of narrow leaflets. The leaflets are supported on a narrow stem lined with spines, hence the name saw. The fruits were collected for both food and medicine by the indigenous people.

This herb, in the form of a dried extract of the fruit, is commonly recommended for the treatment of benign prostatic hyperplasia (BPH) which affects up to 30% of older men. The approach is similar to western pharmaceutical prescribing where 5 alpha-reductase inhibitors (finasteride and dutasteride), or alpha-blockers (tamsulosin) are used. Saw Palmetto is a 5 alpha-reductase inhibitor.¹

The 5 alpha-reductase inhibitors work by suppressing the enzymatic conversion of testosterone to the more active androgen dihydrotestosterone  (DHT) in the prostate, while alpha blockers relax the muscles. Excess androgens lead to increased tone in the prostate tissue as well as hyperplasia. This combination causes bladder obstruction and the ensuing difficulties of urination, or otherwise called lower urinary tract symptoms (LUTS).

A recent 2020 meta-analysis of several clinical trials supports the use of saw palmetto for treating BPH. In this analysis the extract was found similar to tamsulosin in terms of improvements in the International Prostate Symptom Score, post-void residual volume and quality of life.²

In the rodent model, saw palmetto oil also showed comparable results in suppressing BPH when compared to finasteride, this time induced over 28 days with the administration of testosterone. In addition, a β-sitosterol enriched oil was found superior to both finasteride and saw palmetto oil, the β-sitosterol being added for its anti-inflammatory effect. Comparable or not, it has to be remembered that while saw palmetto has demonstrated few serious side-effects (headache, dizziness, stomach upset), finasteride can cause erectile dysfunction, increased risk of impotency and ejaculation disorder.³

Further examination of the herb in the form of a hexane extract shows it to be a potent anti-inflammatory on its own for treating lower urinary tract symptoms.⁴ Nevertheless, when combined with another potent urinary system herb nettle, saw palmetto makes an effective treatment for prostatitis as well as benign prostatic hyperplasia (BPH). These two herbs are used by 60% of such patients in Germany without the side-effects of tamsulosin.⁵

A holistic approach necessary to support the use of herbs in order to get consistent results is mainly dietary. An anti-inflammatory, anti-BPH diet is a wholefood diet similar to the traditional Mediterranean diet. This diet was rich in fruit, pulses and vegetables, oily fish, olive oil, as well as natural full-fat butter and cheese. There were no ultra-processed inflammatory foods, high-fructose corn syrup, margarine, transfats, food additives, or endocrine disrupting chemicals. This diet was supported by a high level of healthy exercise into old age, moderate alcohol consumption and regular herbal teas. Smoking increases 5 alpha-reductase activity, as with abdominal fat.

We often attempt to replicate such ideal pre-industrial conditions in naturopathic clinic with the use of superfoods and evidence-based herbs. We also add antioxidant supplements, vitamins and minerals such as quercetin, lycopene, green tea, turmeric, garlic, magnesium, selenium, zinc and omega-3 to achieve a comparable effect.

Hair loss in another common condition that men suffer from when they age, for which finasteride is used. Men with androgenic alopecia (Pattern Hair Loss) have higher 5 alpha-reductase activity and DHT in hair follicles, and the ability of saw palmetto to correct the underlying androgen imbalance was demonstrated in a human trial of 100 men. The treatment group were given a dried extract of the herb and 38% noted an improvement over 2 years. The effect could be further increased with β-sitosterol in this case as well. A fancy liposterolic extract of saw palmetto administered to mice in another experiment, indicated that it was able to regenerate hair follicles and induce growth. This regeneration occurred through different mechanisms to 5 alpha-reductase inhibition, including inflammatory cytokine modulation and mitochondrial metabolism.^6–8

In homeopathy this herb (Sabal serrulata) is considered nutritive and tissue building. In low potency it supports the genito-urinary system in both sexes, treating cystitis and enuresis. In men it is indicated for BPH with frequent night-time urination, impotence and atrophy, while in women it treats tender ovaries and atrophied breasts. The patient may suffer neuralgia or vertigo, feel apathetic or depressed, and is usually averse sympathy.⁹

A version of this Article appears in the 2021 eBook edition of Wholefoods And Common medicinal Herbs.

Disclaimer:

This article is intended for the purpose of general education only, and is not a substitute for a diagnosis, treatment advice, or a prescription given in a consultation with a qualified physician.

References:

1.         Buonocore D, Verri M, Cattaneo L, Arnica S, Ghitti M, Dossena M. Serenoa repens extracts: In vitro study of the 5α-reductase activity in a co-culture model for Benign Prostatic Hyperplasia. Arch Ital Urol Androl 2018;90:199–202.

2.         Cai T, Cui Y, Yu S, Li Q, Zhou Z, Gao Z. Comparison of Serenoa repens With Tamsulosin in the Treatment of Benign Prostatic Hyperplasia: A Systematic Review and Meta-Analysis. Am J Mens Health 2020;14:1557988320905407.

3.         Sudeep HV, Venkatakrishna K, Amrutharaj B, Anitha  null, Shyamprasad K. A phytosterol-enriched saw palmetto supercritical CO2 extract ameliorates testosterone-induced benign prostatic hyperplasia by regulating the inflammatory and apoptotic proteins in a rat model. BMC Complement Altern Med 2019;19:270.

4.         Latil A, Pétrissans M, Rouquet J, Robert G, de la Taille A. Effects of hexanic extract of serenoa repens (permixon® 160 mg) on inflammation biomarkers in the treatment of lower urinary tract symptoms related to benign prostatic hyperplasia. Prostate 2015;75:1857–67.

5.         Rapp C. Research reviews. Special saw palmetto and stinging nettle root combination as effective as pharmaceutical drug for prostate symptoms. HerbalGram 2006;20–1.

6.         Zhu H-L, Gao Y-H, Yang J-Q, Li J-B, Gao J. Serenoa repens extracts promote hair regeneration and repair of hair loss mouse models by activating TGF-β and mitochondrial signaling pathway. Eur Rev Med Pharmacol Sci 2018;22:4000–8.

7.         Rossi A, Mari E, Scarno M, et al. Comparitive effectiveness of finasteride vs Serenoa repens in male androgenetic alopecia: a two-year study. Int J Immunopathol Pharmacol 2012;25:1167–73.

8.         Prager N, Bickett K, French N, Marcovici G. A randomized, double-blind, placebo-controlled trial to determine the effectiveness of botanically derived inhibitors of 5-alpha-reductase in the treatment of androgenetic alopecia. J Altern Complement Med 2002;8:143–52.

9.         Boericke W. Pocket Manual Of Homoeopathic Materia Medica, c. 1927. Delhi: Indian Books & Periodical Publishers; 2007.