Zedoary Benefits Explained

Zedoary Benefits Explained Unearthing the Comprehensive Health Potential of Curcuma zedoaria

Zedoary, scientifically known as Curcuma zedoaria, is a fascinating and historically significant rhizomatous herb belonging to the ginger family (Zingiberaceae). While its more famous cousins, turmeric (Curcuma longa) and ginger (Zingiber officinale), have dominated the global health supplement stage, zedoary boasts its own unique profile of bioactive compounds and a rich history of use in traditional medicine systems across Asia. Often overlooked in the Western world, this aromatic rhizome possesses a compelling array of potential health benefits that warrant a deep, comprehensive exploration. This article delves into the known science, traditional wisdom, and potential future of zedoary as a powerful dietary supplement.

Decoding Zedoary Botanical Profile and Potent Bioactive Compounds

Curcuma zedoaria is a perennial herb native to South Asia and Southeast Asia, thriving in tropical and subtropical regions. Its underground stem, the rhizome, is the part primarily used for medicinal purposes. Visually, the zedoary rhizome can resemble ginger but often has a more complex, finger-like structure and a distinctive aroma that is spicy, slightly bitter, and camphoraceous, differing noticeably from both ginger and turmeric. The diverse health benefits attributed to zedoary stem directly from its complex phytochemical composition. While it shares some compounds with turmeric, particularly certain curcuminoids in varying amounts, its unique properties are largely due to a distinct blend of essential oils and other non-curcuminoid compounds. Key bioactive constituents include

1. Essential Oils: These are the primary contributors to zedoary’s aroma and many of its biological activities. Major components include

• Zerumbone: A prominent monocyclic sesquiterpene often found in significant quantities. Zerumbone is extensively studied for its anti-inflammatory, antioxidant, and particularly its in vitro and in vivo (animal studies) anticancer potential.
• Curcumenol, Curcumenone, Zederone, Furanodienone: Other sesquiterpenes contributing to anti-inflammatory, antioxidant, and antimicrobial effects.
• Cineole (Eucalyptol): Also found in eucalyptus, known for respiratory benefits.
• Camphor: Contributes to the characteristic aroma and has traditional uses as a counterirritant.
• Alpha and Beta-Pinene, Camphene: Terpenes found in many plants, known for anti-inflammatory and antimicrobial properties.

2. Curcuminoids: While Curcuma longa (turmeric) is the primary source of curcumin, zedoary also contains curcuminoids, including curcumin, demethoxycurcumin, and bisdemethoxycurcumin, albeit typically in lower concentrations than high-curcumin turmeric varieties. These compounds are well-established antioxidants and anti-inflammatories.
3. Polysaccharides: Complex carbohydrates that may contribute to immune-modulating effects.
4. Flavonoids and Phenolic Compounds: Other antioxidant compounds that help combat oxidative stress. The synergistic interplay of these diverse compounds is believed to underpin zedoary’s broad spectrum of potential health benefits, distinguishing it chemically and functionally from its botanical relatives.

Historical Roots Zedoary’s Place in Traditional Medicine Systems

Zedoary has a long and respected history in various traditional healing practices across Asia. Its uses reflect keen observations by ancient practitioners regarding its effects on the body, particularly the digestive and respiratory systems.

• Ayurveda (India): Known as “Shati” or “Kachur,” zedoary has been used for centuries to address digestive complaints, improve appetite, alleviate flatulence and indigestion, and support liver function. It was also traditionally employed for respiratory ailments like coughs, bronchitis, and asthma, as well as for pain relief, skin diseases, and as a blood purifier.
• Traditional Chinese Medicine (TCM): Referred to as “Ezhu,” zedoary is categorized as a herb that invigorates blood circulation and dispels blood stasis. It is primarily used to treat pain associated with stagnation, such as abdominal pain, menstrual cramps, and pain from injuries. It’s also used for indigestion and certain types of tumors or masses (consistent with the “dispelling stagnation” principle).
• Unani Medicine: Zedoary is used for similar purposes as in Ayurveda and TCM, including digestive issues, respiratory problems, and pain relief.
• Southeast Asian Traditional Medicines: Used for postpartum recovery, digestive issues, and as an anti-inflammatory agent. This extensive history of use across diverse cultures points to a consistent recognition of zedoary’s therapeutic properties, providing a valuable foundation for modern scientific inquiry into its potential health benefits.

Zedoary for Digestive Wellness A Gut Health Ally

One of the most prominent and historically documented uses of zedoary is for supporting digestive health. Modern research is beginning to shed light on the mechanisms behind these traditional applications.

• Carminative and Antiflatulent: Zedoary’s essential oils, particularly compounds like cineole and borneol (often found in zedoary oil), have carminative properties. They help relax the smooth muscles of the digestive tract, reducing spasms and promoting the expulsion of gas, thereby alleviating bloating, flatulence, and abdominal discomfort.
• Stimulating Digestion: Zedoary is traditionally used as an appetizer and digestive stimulant. It may work by promoting the secretion of digestive enzymes and bile, which are crucial for breaking down food and absorbing nutrients. This can be particularly helpful for individuals experiencing sluggish digestion or dyspepsia (indigestion).
• Anti-inflammatory Effects on the Gut: Compounds like zerumbone and curcuminoids possess potent anti-inflammatory properties. Chronic inflammation in the gut is implicated in various digestive disorders, including Inflammatory Bowel Diseases (IBD) like Crohn’s disease and ulcerative colitis, as well as Irritable Bowel Syndrome (IBS). While research specifically on zedoary for IBD/IBS in humans is limited, its anti-inflammatory constituents suggest potential in managing inflammation-related gut symptoms.
• Potential Against H. pylori: Some in vitro studies have indicated that zedoary extracts and essential oils may exhibit activity against Helicobacter pylori, a bacterium known to cause gastritis, ulcers, and increase the risk of stomach cancer. This antimicrobial potential could contribute to its traditional use for stomach ailments. Compared to ginger, which is well-known for nausea and digestive motility, or turmeric, often used for gut inflammation, zedoary offers a distinct profile with a strong emphasis on carminative action and potential antimicrobial effects against specific gut pathogens, alongside its anti-inflammatory properties. Its historical use for “dispelling stagnation” in TCM aligns well with its effects on improving flow and reducing discomfort in the digestive system.

Zedoary’s Anti-inflammatory & Pain Relief Potential Unpacked

Inflammation is a root cause of many chronic diseases. Zedoary, like its relative turmeric, is a potent source of anti-inflammatory compounds, offering potential benefits for conditions characterized by inflammation and pain.

• Targeting Inflammatory Pathways: Research indicates that zedoary’s bioactive compounds, especially zerumbone, can modulate key inflammatory pathways. Zerumbone has been shown in studies to inhibit the activity of NF-κB (Nuclear Factor kappa-light-chain-enhancer of activated B cells), a protein complex that controls DNA transcription and is central to regulating the immune response and inflammation. By suppressing NF-κB, zerumbone can reduce the production of pro-inflammatory cytokines (like TNF-α, IL-1β, IL-6) and enzymes like COX-2 (Cyclooxygenase-2), which are involved in pain and inflammation.
• Reducing Swelling and Pain: The inhibition of COX-2 is a mechanism targeted by many NSAIDs (non-steroidal anti-inflammatory drugs). While zedoary is not a drug and its effects are likely milder and multifaceted, this mechanism suggests potential for reducing inflammation and associated pain, as supported by its traditional use for various painful conditions.
• Potential for Arthritis and Joint Health: Given its anti-inflammatory effects, zedoary could potentially offer support for inflammatory joint conditions like osteoarthritis and rheumatoid arthritis, similar to how turmeric is used. While specific human trials on zedoary for arthritis are needed, the preclinical evidence on its compounds is promising.
• Beyond Joint Pain: The anti-inflammatory properties extend beyond joints, potentially offering benefits for inflammatory conditions affecting other parts of the body, such as inflammatory skin conditions or respiratory tract inflammation, aligning with traditional uses. While turmeric’s anti-inflammatory power is largely attributed to curcumin, zedoary’s strength lies significantly in zerumbone and the synergy of its essential oils. This provides an alternative or complementary botanical approach to managing inflammation compared to relying solely on curcumin.

Zedoary as a Cellular Guardian Antioxidant Powerhouse

Oxidative stress, caused by an imbalance between free radicals and antioxidants in the body, contributes significantly to aging and the development of chronic diseases. Zedoary is rich in compounds that can help combat this damage.

• Free Radical Scavenging: Zedoary’s phenolic compounds, flavonoids, curcuminoids, and essential oil components (including zerumbone) act as direct free radical scavengers. They can neutralize reactive oxygen species (ROS) and reactive nitrogen species (RNS), preventing them from damaging cellular components like DNA, proteins, and lipids.
• Boosting Endogenous Antioxidant Systems: Beyond directly neutralizing free radicals, zedoary compounds can also enhance the body’s own defense mechanisms. Studies suggest they can upregulate the activity of key endogenous antioxidant enzymes such as Superoxide Dismutase (SOD), Catalase, and Glutathione Peroxidase. These enzymes play a critical role in detoxifying harmful byproducts of cellular metabolism.
• Protecting Against Oxidative Damage: By reducing oxidative stress and enhancing antioxidant defenses, zedoary may help protect cells and tissues from damage. This has implications for overall cellular health, potentially reducing the risk of age-related decline and chronic diseases linked to oxidative damage, including cardiovascular disease, neurodegenerative disorders, and certain cancers. Zedoary’s comprehensive antioxidant profile, involving both direct scavenging and enzymatic boosting, positions it as a valuable supplement for supporting cellular resilience against daily environmental and metabolic stressors.

Fighting Pathogens Zedoary’s Antimicrobial and Antifungal Actions

Traditional uses of zedoary often included treating infections. Modern research supports these uses, demonstrating that zedoary possesses notable antimicrobial and antifungal properties.

• Antibacterial Activity: Studies have shown that zedoary extracts and essential oils can inhibit the growth of various bacteria, including foodborne pathogens like Escherichia coli, Staphylococcus aureus, and Salmonella typhimurium. As mentioned earlier, activity against Helicobacter pylori, a bacterium implicated in stomach ulcers and cancer, has also been reported in vitro.
• Antifungal Activity: Zedoary has demonstrated effectiveness against various fungal species, including Candida albicans, a common cause of yeast infections, and dermatophytes that cause skin infections. The essential oil components, particularly sesquiterpenes, are believed to be responsible for these effects.
• Mechanisms: The mechanisms behind zedoary’s antimicrobial action are thought to involve disrupting bacterial cell membranes, inhibiting enzyme activity essential for microbial survival, or interfering with biofilm formation. These properties suggest that zedoary could potentially play a role in supporting the body’s defense against certain microbial challenges, whether ingested or applied topically in appropriate formulations. Its use in traditional medicine for skin conditions also aligns with its observed antifungal and antibacterial activities.

Promising Avenues Zedoary in Anticancer Research Insights

It is critical to state upfront that zedoary is not a treatment or cure for cancer. However, preclinical research (studies in laboratories using cancer cells and in animal models) on zedoary and its components, particularly zerumbone and furanodienone, has yielded promising insights into potential anticancer mechanisms. This is an active area of research, not established clinical practice.

• Inducing Apoptosis (Programmed Cell Death): Zerumbone and other zedoary compounds have been shown in vitro to induce apoptosis in various types of cancer cells, including those from the colon, breast, liver, lung, and skin. Unlike healthy cells, cancer cells often evade this natural process. Zedoary compounds appear to trigger pathways that lead cancer cells to self-destruct.
• Inhibiting Cancer Cell Proliferation: Zedoary extracts and isolated compounds have demonstrated the ability to slow down or halt the rapid division and growth of cancer cells in laboratory settings.
• Preventing Angiogenesis: Tumor growth and metastasis require the formation of new blood vessels (angiogenesis) to supply nutrients. Some studies suggest that zedoary compounds may inhibit angiogenesis, potentially starving the tumor.
• Anti-metastatic Potential: Metastasis is the spread of cancer cells to distant sites, which is often the most life-threatening aspect of the disease. Preclinical research hints that zedoary compounds might interfere with processes involved in metastasis, such as cell migration and invasion.
• Modulating Signaling Pathways: Zedoary compounds interact with various cellular signaling pathways that are often dysregulated in cancer, including NF-κB, STAT3, and others involved in cell survival, proliferation, and inflammation. These findings are exciting from a research perspective, identifying zedoary compounds as potential candidates for further investigation in cancer prevention or adjunct therapy. However, the transition from in vitro and animal studies to safe and effective human treatments is a long and complex process. Human clinical trials are necessary to determine if zedoary or its components have any role in cancer management in people.

Supporting Liver Function Zedoary for Hepatic Health

Traditional medicine systems have long utilized zedoary to support liver health and address various liver-related issues. Modern understanding points to several ways zedoary might benefit the liver.

• Hepatoprotective Effects: The antioxidant and anti-inflammatory properties of zedoary compounds are key to its potential liver benefits. The liver is constantly exposed to toxins and oxidative stress. By reducing inflammation and scavenging free radicals, zedoary may help protect liver cells from damage induced by toxins, medications, or diseases.
• Promoting Bile Flow: Zedoary is traditionally used to stimulate bile secretion. Bile is produced by the liver and aids in the digestion and absorption of fats. By promoting bile flow, zedoary may help improve fat digestion and potentially aid the liver in eliminating waste products. However, this property means caution is advised for individuals with gallstones, as stimulating bile flow could potentially cause complications.
• Detoxification Support: While not a direct detoxifier in the sense of chelating heavy metals, by supporting liver function, reducing inflammation, and providing antioxidants, zedoary contributes to the liver’s crucial role in the body’s natural detoxification processes. Zedoary’s traditional role in liver support is biologically plausible given its rich profile of compounds known to protect cells from damage and inflammation, key factors in liver health.

Zedoary for Respiratory Comfort and Relief

Another area of traditional use for zedoary is in addressing respiratory ailments, including coughs, colds, and congestion.

• Expectorant Properties: Zedoary is traditionally considered an expectorant, meaning it helps loosen mucus in the respiratory tract, making it easier to cough up. This effect is likely linked to its aromatic essential oils, which can have a stimulating effect on the respiratory passages.
• Anti-inflammatory Effects: Inflammation in the airways contributes to symptoms of bronchitis, asthma, and colds. Zedoary’s anti-inflammatory compounds could potentially help reduce this inflammation, easing breathing and reducing cough severity.
• Antimicrobial Potential: As discussed, zedoary has activity against certain bacteria and fungi. While not a substitute for conventional treatment of respiratory infections, its antimicrobial properties might offer some supportive benefit against pathogens that affect the respiratory system.
• Potential Bronchodilatory Effects: Some traditional uses suggest an effect similar to bronchodilators, helping to open airways. While specific modern research on this effect is limited, certain essential oil components in other plants are known to have mild bronchodilatory properties. While more targeted research is needed to confirm these effects, the combination of traditional use and the presence of relevant bioactive compounds makes zedoary a potentially interesting natural support for respiratory health.

Zedoary and Women’s Health Traditional Uses Explored

In several traditional medicine systems, zedoary has been used to address specific issues related to women’s reproductive health, particularly menstrual discomfort.

• Menstrual Cramps and Pain: Zedoary’s anti-inflammatory and potential antispasmodic properties are likely the basis for its traditional use in alleviating menstrual cramps (dysmenorrhea). By reducing inflammation and relaxing smooth muscles, it may help ease the painful contractions of the uterus.
• Regulating Menstrual Cycles: Some traditional texts mention zedoary’s use in helping to regulate irregular menstrual cycles or address amenorrhea (absence of menstruation). The mechanisms for this are less clear and may relate to improving overall vitality or blood circulation (as per TCM principles of dispelling blood stasis). It is important to note that while traditional use is a guide, modern scientific validation specifically for these applications in women’s health is limited. Women who are pregnant or breastfeeding should avoid zedoary (see precautions section).

Exploring Other Potential Zedoary Benefits (Requires More Research)

Beyond the more prominent traditional and research-backed uses, zedoary may offer other potential health benefits, though these areas require significantly more scientific investigation.

• Cardiovascular Health: Zedoary’s antioxidant and anti-inflammatory effects could theoretically contribute to cardiovascular health by protecting blood vessels from oxidative damage and reducing inflammation, which are factors in atherosclerosis. Some research on zerumbone has explored effects on blood pressure and cholesterol in animal models, but human data is lacking.
• Blood Sugar Regulation: Some traditional systems hint at a role for zedoary in metabolic health or blood sugar balance. Preclinical studies on certain Curcuma species have shown potential effects on glucose metabolism, but specific research on Curcuma zedoaria for diabetes is limited and not conclusive.
• Stress and Anxiety: The aromatic compounds in zedoary essential oil have been traditionally used in aromatherapy for their calming or uplifting effects. While subjective, the inhalation of certain terpenes can impact mood and stress levels. This area is largely based on traditional/aromatic use rather than robust clinical trials. These potential benefits are intriguing but currently sit on the frontier of zedoary research. They highlight the need for further studies to fully understand the breadth of its therapeutic potential.

Zedoary vs. Turmeric vs. Ginger A Comparative Look

Given their shared family and some overlapping traditional uses, it’s natural to compare zedoary with its more famous relatives, turmeric and ginger. While they share some common ground, their differences are significant and highlight zedoary’s unique value.

• Shared Traits: All three are Zingiberaceae rhizomes used in traditional medicine, known for digestive benefits, and possessing anti-inflammatory and antioxidant properties.
• Key Differentiators - Bioactive Compounds:
• Turmeric: Dominated by curcuminoids, especially curcumin, which is the primary focus of its anti-inflammatory and antioxidant research.
• Ginger: Characterized by gingerols and shogaols, known for anti-nausea effects, digestive motility support, and anti-inflammatory properties.
• Zedoary: Distinguished by its high content of specific sesquiterpenes like zerumbone and furanodienone, which drive many of its researched effects, particularly in the areas of anti-inflammation, antioxidant activity, and preclinical anticancer studies. While it contains curcuminoids, they are typically not the primary active constituents or present in as high concentrations as in turmeric extracts standardized for curcumin.
• Functional Differences:
• Turmeric excels as a broad-spectrum anti-inflammatory and antioxidant due to curcumin.
• Ginger is unparalleled for nausea relief and stimulating digestive motility.
• Zedoary offers strong carminative action (gas relief), distinct antimicrobial properties (especially H. pylori and fungi), and its unique profile of sesquiterpenes provides a different angle for anti-inflammatory and potential anticancer research compared to curcumin or gingerols. Viewing zedoary not as a weaker version of turmeric or ginger, but as a distinct herb with its own powerful set of compounds and traditional applications, allows for a deeper appreciation of its potential as a complementary dietary supplement. Its specific strengths in areas like zerumbone’s documented effects and its traditional use for “dispelling stagnation” offer benefits that are not fully replicated by turmeric or ginger.

Incorporating Zedoary Forms and Dosage Considerations

Zedoary is available in various forms as a dietary supplement, reflecting both traditional use and modern processing.

• Powdered Rhizome: The dried and ground rhizome can be used in capsules, mixed into foods (though its bitter, camphoraceous taste is distinct), or brewed as a tea (often blended with other herbs).
• Capsules/Tablets: Containing standardized or non-standardized powdered zedoary or extracts. Extracts may concentrate specific compounds like essential oils or curcuminoids, though standardization for zerumbone is less common than for curcumin.
• Tinctures: Alcohol or glycerin extracts of the rhizome.
• Essential Oil: Highly concentrated and should be used with extreme caution, typically only under the guidance of a qualified practitioner, and never ingested unless specifically formulated and recommended for internal use by a professional, as essential oils can be toxic in incorrect doses. Primarily used externally or in aromatherapy. Dosage: There is no universally standardized dosage for zedoary supplements. Dosage recommendations vary widely depending on the form (raw powder vs. extract), the concentration of active compounds, and the intended use.
• Traditional Use: Often involved using small amounts of the fresh or dried rhizome in cooking or brewing teas.
• Supplement Labels: Always follow the dosage instructions provided on the supplement product label, as these are typically based on the manufacturer’s formulation and safety assessments.
• Lack of Clinical Trials: Due to the limited number of human clinical trials on zedoary for specific health conditions, optimal therapeutic dosages for particular benefits are not well-established in scientific literature. Consult a Healthcare Professional: Given the variability and lack of standardized clinical data, it is highly recommended to consult with a qualified healthcare professional or a registered dietitian/herbalist before starting zedoary supplementation, especially if you have pre-existing health conditions, are taking medications, or are pregnant/breastfeeding.

Safety Profile, Side Effects, and Precautions

Zedoary is generally considered safe when consumed in food amounts. However, as a concentrated dietary supplement, certain precautions and potential side effects should be considered.

• Potential Side Effects: Zedoary is usually well-tolerated. Mild digestive upset, such as nausea or stomach irritation, is possible, particularly with larger doses or on an empty stomach.
• Gallstones: Zedoary stimulates bile production and flow. While this can be beneficial for digestion, it could potentially cause pain or complications in individuals with gallstones or bile duct obstruction. Avoid use if you have these conditions unless directed by a doctor.
• Pregnancy and Breastfeeding: Zedoary has been traditionally used for postpartum recovery in some cultures, but its effects on pregnancy are not well-studied. Some traditional systems consider it to stimulate menstruation or blood flow, which could be problematic during pregnancy. Due to the lack of safety data, zedoary is generally not recommended during pregnancy or breastfeeding.
• Bleeding Disorders and Anticoagulant Medications: Some compounds in zedoary, similar to those in ginger and turmeric, might have mild anti-platelet or anticoagulant effects, potentially increasing the risk of bleeding, especially in susceptible individuals or those taking blood-thinning medications (like warfarin, aspirin, clopidogrel). Use with caution and consult your doctor if you have a bleeding disorder or are on blood thinners.
• Surgery: Due to the potential for increased bleeding risk, discontinue zedoary supplementation at least two weeks before any scheduled surgery.
• Medication Interactions: Zedoary compounds could potentially interact with certain medications, particularly those metabolized by liver enzymes (CYP450 enzymes). Consult your doctor or pharmacist about potential interactions if you are taking any prescription medications.
• Allergies: Individuals with allergies to other members of the ginger family (ginger, turmeric, cardamom) may also be sensitive to zedoary. Always source zedoary supplements from reputable manufacturers to ensure product quality and purity.

The Future of Zedoary Research and Integration

Despite its long history of traditional use, zedoary remains relatively understudied compared to turmeric and ginger in the context of modern clinical research. The future of zedoary as a dietary supplement lies in several key areas

• Human Clinical Trials: Robust, well-designed clinical trials are needed to confirm the efficacy and safety of zedoary for specific health conditions in humans. This includes studies on its effects on digestive disorders, inflammatory conditions, pain management, and its potential role in supportive care.
• Standardization: Developing standardized extracts based on key bioactive markers like zerumbone, furanodienone, or specific essential oil profiles would allow for more consistent dosing and reproducible research findings.
• Mechanism Elucidation: Further research is needed to fully understand the complex interactions of zedoary’s numerous compounds and the precise molecular pathways they influence.
• Bioavailability Studies: Investigating the bioavailability of zedoary compounds (how well they are absorbed and utilized by the body) is important for optimizing dosage and formulation.
• Combination Therapies: Exploring the potential synergistic effects of zedoary compounds when combined with other botanicals or conventional therapies, particularly in areas like inflammation or supportive cancer care (under medical supervision). As scientific interest grows in traditional botanicals and the search for novel therapeutic compounds continues, zedoary is well-positioned to emerge from the shadow of its famous relatives. Its unique chemical profile, particularly its rich essential oil content and prominent sesquiterpenes like zerumbone, offers distinct avenues for research and potential health benefits that complement rather than simply duplicate those of turmeric or ginger.

Conclusion Zedoary’s Place in Holistic Wellness

Zedoary (Curcuma zedoaria) is a potent and historically significant herb with a rich tapestry of traditional uses, primarily centered around digestive health, anti-inflammation, pain relief, and respiratory support. Modern scientific investigation, though still in its early stages compared to turmeric and ginger, is beginning to validate many of these traditional claims, particularly highlighting the significant roles of its unique essential oil components like zerumbone. From acting as a powerful carminative and digestive stimulant to demonstrating promising anti-inflammatory, antioxidant, antimicrobial, and even preclinical anticancer activities, zedoary possesses a compelling profile of potential health benefits. Its distinct phytochemical composition sets it apart from its botanical cousins, offering a unique approach to addressing various health concerns. While the existing research, particularly in vitro and animal studies, provides exciting insights, robust human clinical trials are essential to fully understand zedoary’s efficacy, optimal dosage, and long-term safety for specific conditions. As with any dietary supplement, zedoary should not be considered a substitute for conventional medical treatment. However, for those interested in exploring the potential of traditional botanicals supported by emerging science, zedoary represents a valuable and intriguing option. When used responsibly, preferably under the guidance of a healthcare professional, zedoary has the potential to be a beneficial addition to a holistic wellness regimen, drawing on centuries of traditional wisdom and the growing body of modern scientific evidence.