Saw Palmetto's Role in Hormonal Balance and Prostate Health

According to a 2018 study, at least one lower urinary tract symptom affects over one billion men worldwide. Based on this number, it's no surprise that people are turning to natural therapies to support urinary health. Since the 1990s, saw palmetto has been one of the top-selling herbal medicines in the United States, with some statistics estimating that 2.5 million men use saw palmetto extract to treat lower urinary tract symptoms. Benign prostatic hyperplasia (BPH) is one of the most common causes of urological symptoms in men, and accumulating evidence from over 35 clinical trials supports the use of saw palmetto extract for treating BPH-associated urinary symptoms. (4, 23)

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Understanding Hormonal Balance and Prostate Health

Hormonal regulation in men is a complex and interconnected process involving the coordination of several endocrine axes, namely the Hypothalamic-Pituitary-Thyroid (HPT), Hypothalamic-Pituitary-Adrenal (HPA), and Hypothalamic-Pituitary-Gonadal (HPG) axes. These axes work harmoniously to maintain hormonal balance, influencing various physiological functions crucial for overall health. (11) 

The Hypothalamic-Pituitary-Thyroid (HPT) axis governs the regulation of thyroid hormones, essential for metabolism, energy balance, and growth. The hypothalamus releases thyrotropin-releasing hormone (TRH), stimulating the pituitary gland to produce thyroid-stimulating hormone (TSH), which, in turn, prompts the thyroid gland to secrete thyroxine (T4) and triiodothyronine (T3). 

The Hypothalamic-Pituitary-Adrenal (HPA) axis is integral for managing the body's response to stress. The hypothalamus releases corticotropin-releasing hormone (CRH), stimulating the pituitary gland to produce adrenocorticotropic hormone (ACTH). ACTH then signals the adrenal glands to release cortisol, the primary stress hormone. Cortisol influences metabolism, immune function, and helps the body respond effectively to stressors. (9) 

The Hypothalamic-Pituitary-Gonadal (HPG) axis regulates reproductive hormones. The hypothalamus releases gonadotropin-releasing hormone (GnRH), stimulating the pituitary gland to secrete luteinizing hormone (LH) and follicle-stimulating hormone (FSH). These hormones, in turn, modulate the activity of the testes, regulating the production of testosterone and supporting sperm development. 

In men, testosterone is required for the development of male reproductive tissues, including the testes and prostate, and secondary sexual characteristics. It builds and maintains muscle mass, bone density, and red blood cells, impacts mood, and influences cognitive function.  

Whether too high or too low, testosterone imbalances can have significant implications for men's health. Excessive testosterone levels may lead to increased aggression, acne, and an enlarged prostate. Benign prostatic hyperplasia (BPH) is a noncancerous enlargement of the prostate gland that occurs in up to 90% of men by age 85 years and causes symptoms in 25% of men by age 55 and 50% of men by age 75. BPH symptoms include urinary frequency, urgency, hesitancy, a weak urine stream, and nocturia (frequent nighttime urination). Conversely, low testosterone levels can result in decreased libido, muscle mass loss, fatigue, and an increased risk of osteoporosis. 

Saw Palmetto: Historical Use and Properties

Saw palmetto (Serenoa repens) is a small palm native to the southeastern United States. It thrives in sandy soils and is characterized by fan-shaped leaves and dark berries. The active constituents of saw palmetto include fatty acids, phytosterols, and flavonoids. The lipophilic extract obtained from the berries contains a high concentration of these bioactive compounds. Fatty acids, including capric, caprylic, caproic, lauric, palmitic, and oleic acids, contribute to saw palmetto's anti-inflammatory properties, while phytosterols, such as beta-sitosterol, are believed to influence hormone metabolism. Together, these phytochemicals contribute to the herb's anti-androgenic, antiproliferative, and anti-inflammatory effects. (4, 23) 

In traditional medicine, Native American communities used saw palmetto for its diuretic and expectorant properties to treat genitourinary conditions and coughs. Its use expanded to the management of reproductive issues, including enhancing fertility and addressing symptoms associated with an enlarged prostate. In modern herbal medicine, saw palmetto has gained prominence for its potential efficacy in managing BPH because of its ability to inhibit the conversion of testosterone to dihydrotestosterone (DHT). Saw palmetto supplements are also promoted for managing chronic pelvic pain, migraine, and hair loss. (5, 18) 

Saw Palmetto in Hormonal Regulation

In adults, 10% of testosterone is converted to the more potent androgen, DHT, daily. In men, this conversion occurs in the prostate and genital skin by the enzyme called 5-alpha-reductase. DHT is responsible for the growth of body hair, the penis, the scrotum, and the prostate. Excessive levels are associated with increased prostate cell proliferation, which can contribute to the enlargement of the prostate gland and symptoms of BPH. Pharmacologic agents that inhibit 5-alpha-reductase and, therefore, inhibit the conversion of testosterone to DHT are one of the treatment options for mild-to-moderate symptoms of an enlarged prostate. Finasteride is a popular 5-alpha-reductase inhibitor prescribed to treat BPH. 

Saw palmetto has gained attention as a natural inhibitor of 5-alpha-reductase. This enzyme has two isoforms, 5-alpha-reductase 1 and 2. Finasteride competitively inhibits 5-alpha-reductase 2, whereas saw palmetto inhibits both isoforms noncompetitively. Saw palmetto's fat-soluble constituents, such as sterols and fatty acids, appear most responsible for its inhibitory actions. Di Silverio et al. confirmed saw palmetto's anti-androgenic effects by measuring significant decreases in DHT and increases in testosterone in BPH tissue samples from men receiving saw palmetto extract daily for three months. (23) 

Additional evidence suggests that, in addition to inhibiting the conversion of testosterone to DHT, saw palmetto extract also inhibits DHT from binding to its receptor on prostatic cells, further enhancing its anti-androgenic effects. 

Saw Palmetto and Prostate Health

In men, the urethra runs through the prostate gland. When the prostate is enlarged, such as in BPH, men may have trouble urinating. Studies using the International Prostate Symptom Score (IPSS), a standardized tool for evaluating BPH symptoms, have reported improvements and the absence of progression of urinary symptoms, such as nocturia, weak urinary stream, and hesitancy, among men with BPH taking saw palmetto (21, 29). 

In a 1998 JAMA systematic review including 18 randomized controlled trials and nearly 3,000 men, researchers concluded that saw palmetto extract, administered for an average of nine weeks, improves urinary symptoms and peak urinary flow measures in men with symptomatic BPH.

In a more recent Cochrane Review, investigators conducted a meta-analysis of 21 randomized controlled studies comparing saw palmetto with placebo or other drugs for treating moderate BPH symptoms over 4-48 weeks. Compared with placebo, saw palmetto extract improved urinary symptom scores, symptoms, and flow measures. Saw palmetto also produced comparable improvements in urinary symptom scores to finasteride with fewer adverse side effects. 

It's important to note that not all studies have consistently supported using saw palmetto to treat BPH. For example, a large, high-quality study funded by the National Institutes of Health in 2011 found that saw palmetto was no better than placebo in relieving lower urinary tract symptoms attributed to BPH. Variability in study design, patient characteristics, and the formulations of saw palmetto extracts may contribute to conflicting results. 

Dosage and Administration of Saw Palmetto

Saw palmetto supplements can come in capsule, soft gel, tablet, tincture, and powdered form. Different saw palmetto products, despite being derived from the same plant, may exhibit distinct activities due to variations in the composition of bioactive components within the plant extracts. This composition disparity may contribute to the heterogeneity in its efficacy. Permixon, a hexane extract, is saw palmetto's most widely studied form. Clinical studies using Permixon have consistently reproduced results demonstrating improved BPH urinary symptoms. Compared to other saw palmetto products, Permixon contains the highest content of free fatty acids. Therefore, looking for saw palmetto extracts with 80-90% fatty acids is recommended. The recommended daily dose of saw palmetto extract is 320 mg. (16, 20)

Potential Interactions and Side Effects

Saw palmetto is generally safe when used as directed. Side effects are rare but may include mild headache, nausea, and diarrhea. According to case reports, saw palmetto may have anticoagulant effects and, therefore, increase the risk of bleeding when taken concurrently with blood-thinning and anticoagulant medications, such as warfarin, clopidogrel, and aspirin. (17-19)

Prostate cancer and BPH can present with similar symptoms. Do not self-treat for BPH with saw palmetto without first being evaluated by a doctor to rule out prostate cancer.

Integrating Saw Palmetto with Other Natural Therapies

Integrative medicine adopts a holistic lens in managing men's hormonal and prostatic health by emphasizing a comprehensive understanding of the individual's overall well-being. Rather than merely addressing symptoms, this approach seeks to identify and correct underlying causes of health issues. In the context of men's hormonal health, integrative medicine recognizes the interconnectedness of various physiological systems, emphasizing thyroid, adrenal, and testicular health. These endocrine systems play vital roles in hormone regulation, and imbalances can impact testosterone levels and contribute to prostatic issues.

This holistic approach extends beyond pharmaceutical interventions and acknowledges the importance of lifestyle factors, environmental exposures, stress, gut health, and chronic inflammation in influencing hormonal imbalances. In addition to removing obstacles and establishing healthy foundations for hormonal health, integrative medicine also incorporates specific supplements like saw palmetto and essential minerals such as zinc and selenium, which play roles in supporting the immune system and general prostatic wellness. (8) 

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Saw Palmetto for Prostate Health

The benefits of saw palmetto for hormonal and prostate health are increasingly recognized, with this herbal remedy showing promise in supporting a balanced endocrine system and addressing prostate-related concerns. Its potential to inhibit 5-alpha-reductase, a key enzyme in the conversion of testosterone to dihydrotestosterone, positions saw palmetto as a natural solution for managing hormonal imbalances that may contribute to prostate enlargement. However, the efficacy of saw palmetto can vary based on factors such as product composition and individual health profiles, underscoring the importance of personalized approaches and quality supplementation. Seeking professional guidance is essential to navigate the nuances of herbal remedies, ensuring that saw palmetto is incorporated into a comprehensive plan tailored to individual health needs and complements medical standards for optimal hormonal and prostate health.