Introduction
Overview of thyme
Thyme (Thymus vulgaris), a fragrant herb belonging to the Lamiaceae mint family, is esteemed for both its culinary and aromatic qualities, derived from its dried leaves and flowering tops.1 Indigenous to Eurasia, thyme is extensively cultivated worldwide. Its utilisation spans across various culinary applications, including seasoning chicken, fish, eggs, sauces, meats, soups, cheeses, vegetables, and pasta, owing to its distinct flavour profile. The principal constituent of its essential oil, thymol (also known as thyme camphor), finds application in dentifrices and perfumery. Certain thyme varieties are cultivated for ornamental ground cover.
Thyme manifests as a diminutive, herbaceous shrub, bearing simple leaves ranging from oval to linear, arranged oppositely along relatively woody stems. Notably, its flowers are highly attractive to bees, contributing to the renowned thyme honey of Sicily. Rich in bioactive compounds, thyme stands out as a significant therapeutic herb.2
Despite its medicinal potential, thyme's role as a natural food preservative remains underutilised, despite studies demonstrating its efficacy in prolonging the shelf-life of various food products and mitigating lipid oxidation.
Significance of digestive health
The gastrointestinal tract, encompassing the digestive system along with the liver, pancreas, and gallbladder, plays a pivotal role in nutrient processing and absorption. Comprising a convoluted tube extending from the mouth to the anus, the GI tract comprises several hollow organs, including the mouth, oesophagus, stomach, small and large intestines, and anus, complemented by solid organs such as the pancreas, liver, and gallbladder.
Digestion, imperative for nutrient assimilation and bodily function, entails the breakdown of ingested food into absorbable components, including lipids, proteins, carbohydrates, vitamins, minerals, and water. Neurological and hormonal signalling mechanisms orchestrate the digestive process, facilitating the coordination between the GI tract and the brain.3
Nutritional composition of thyme
Essential nutrients in thyme
Thyme harbours a diverse array of chemicals and essential oils, with variations influenced by geographical location and climatic conditions. Constituents include oxygenated sesquiterpenes (1.84%), sesquiterpene hydrocarbons (5.04%), monoterpene hydrocarbons (28.69%), and monoterpenes (56.53%), as evidenced by research. Abundant flavonoids and phenolic antioxidants such as lutein, pigenin, naringenin, luteolin, and thymosin contribute to its therapeutic profile.
Furthermore, thyme boasts an impressive nutritional profile, featuring significant amounts of potassium, iron, calcium, manganese, magnesium, and selenium, crucial for optimal health. Thymol, a primary phenolic component, imparts antioxidant properties to thyme. Additionally, the flowering stem of thyme contains tannins, phenolic acids (e.g., muscarinic and caffeic acids), and flavonoid derivatives (e.g., luteolol and apigenol), further enhancing its nutritional value.
Nutritional profile of thymus vulgaris.4
| Principle | Nutrient value per 100g of fresh leaves | Percentage of RDA |
|---|---|---|
| Niacin | 1.824mg | 11% |
| Pantothenic acid | 0.409mg | 8% |
| Pyridoxine | 0.348mg | 27% |
| Riboflavin | 0.471mg | 36% |
| Thiamin | 0.48mg | 4% |
| Vitamin-A | 4751IU | 18% |
| Vitamin-C | 160.1mg | 266% |
| Sodium | 9mg | 0.5% |
| Potassium | 609 mg | 13% |
| Calcium | 405mg | 40.5% |
| Iron | 17.4mg | 218% |
| Magnesium | 160mg | 40% |
Mechanisms of action
Antimicrobial properties of thyme
Thyme's essential oil harbours potent antimicrobial properties attributed to its high phenolic compound content. Thymol, a prominent constituent, demonstrates bacterial regulation properties, acting as a natural preservative. Studies indicate synergistic interactions among essential oil molecules, exemplified by the relationship between carvacrol and its precursor, p-cymene. Notably, the efficacy of thyme essential oil and thymol in combating microbial growth is heightened under anaerobic conditions and influenced by physical parameters such as low pH, oxygen content, and temperature. However, interactions with food ingredients may diminish the antibacterial activity of essential oil components in food products. Research suggests that thymol disrupts bacterial cell membranes, leading to leakage of intracellular components and inhibition of ATP production and biomolecule synthesis in certain bacteria. Moreover, thyme's antimicrobial, expectorant, anti-inflammatory, antitussive, analgesic, sedative, and anti-broncholytic properties are attributed to its antifungal, antibacterial, antiparasitic, and antiviral activities.
Isomeric phenolic substances like thymol and carvacrol exhibit efficacy against Bacillus cereus, with carvacrol's hydrophobic nature compromising bacterial cell membrane integrity and potential, akin to thymol. Carvacrol functions as a proton exchanger, lowering the plasma membrane's pH.6
Antioxidant properties of thyme
The antioxidant potential of thyme extracts primarily stems from their phenolic compound content. These compounds demonstrate metal ion chelation, oxidative enzyme inhibition, and free radical scavenging activities. Technological advancements enable the identification and measurement of phenolic compounds and their antioxidant activity. However, studies suggest a lack of correlation between total phenolic content and antioxidant efficacy, though certain extracts exhibit a relationship between antioxidant capacity and phenolic content. Thyme phenols exhibit antioxidant properties through free radical neutralisation and redox modulation.
Advantages of thyme in digestive support
Thyme offers various digestive benefits, including:
- Alleviation of Bloating and Gas
- Improvement of Gut Motility
- Reduction of Irritable Bowel Syndrome (IBS) Symptoms
- Protection Against Gastric Ulcers
Thyme and its constituents demonstrate activity in the intestinal and stomach environments, as evidenced by numerous studies. Thyme extract administration may alleviate dyspepsia, while specific components enhance digestive and pancreatic enzyme activity, stimulate appetite, and improve liver function. Thymol and carvacrol exhibit spasmolytic effects and may relax smooth muscles, potentially through calcium channel antagonism or histamine and acetylcholine receptor inhibition.
In experimental animal models, carvacrol administration prevents gastric epithelial damage and reduces chemically induced gastrointestinal injuries. Moreover, alpha-terpineol demonstrates gastroprotective effects against ulcer-inducing drugs. Mechanistically, these effects may involve modulation of prostaglandin synthesis and suppression of stomach acid secretion.
Studies suggest that carvacrol's gastroprotective effects against acetic acid-induced gastric ulcers may involve inhibition of the inflammatory response. Furthermore, carvacrol enhances endogenous prostaglandin production, increases mucus production, suppresses pro-inflammatory cytokine TNF-α, and modulates antioxidant activity.
Thyme oil exhibits therapeutic potential in conditions such as ulcerative colitis and Crohn's disease, as observed in experimental studies. Administration of thymol activates genes associated with mitosis, cell division regulation, and stomach digestion, highlighting its role in gastrointestinal health.5
Dosage and administration
Recommended dosage forms (tea, tincture, capsules)
Determining the appropriate dosage of thyme necessitates consideration of various factors including age, health status, and individual conditions. At present, there exists insufficient scientific data to establish a definitive safe dosage range for thyme. It is imperative to acknowledge the significance of dosage and the potential risks associated with natural products. Hence, it is prudent to meticulously scrutinise product labels and seek guidance from healthcare professionals, such as physicians, pharmacists, or other qualified practitioners, before utilising thyme products.
Considerations for specific populations (pregnant women, children)
Children: Children can likely safely consume thyme in typical dietary amounts. However, caution is warranted when employing thyme medicinally, particularly in elevated doses. The safety profile of thyme oil for children, whether administered topically or orally, remains inadequately established.
Breastfeeding and Pregnancy: Consumption of thyme in regular dietary quantities appears safe for pregnant and breastfeeding women. Nonetheless, the safety of larger medicinal doses of thyme remains uncertain. Pregnant and breastfeeding individuals are advised to adhere to recommended serving sizes.
Blood Clotting Disorders: Thyme possesses the potential to influence blood clotting. Excessive consumption of thyme may elevate the risk of bleeding, particularly among individuals with blood clotting disorders.
Potential side effects and contraindications
Allergic reactions
Although the prevalence of these side effects is not well-delineated, thyme oil medications have been associated with allergic reactions and skin irritation. Individuals allergic to thyme oil are cautioned against the use of thyme oil-based medications. Furthermore, the application of thyme oil medications for full-body hot baths is discouraged in cases of open wounds, severe skin injuries or disorders, high fever, serious infections or circulatory issues, high blood pressure, or heart failure. Application of thyme oil medications on the face is also not recommended.
Interactions with medications
In a study, varied concentrations of thyme exhibited a dose-dependent inhibitory effect against CYP3A4, an enzyme accountable for the metabolism and inactivation of orally administered drugs. Notably, CYP3A4 is implicated in several clinically significant drug-drug interactions, emphasising the necessity of considering potential interactions with medications metabolised by this enzyme.
Summary
In summary, Thymus vulgaris emerges as a notable aromatic and medicinal plant, historically harnessed in culinary, preservative, and phytopharmaceutical realms. Bioactive monoterpenes, including thymol, carvacrol, and linalool, featured in its essential oil, showcase diverse properties encompassing antifungal, antibacterial, antioxidative, and anti-inflammatory attributes. Thyme essential oil demonstrates efficacy against fungal and bacterial pathogens.
Studies delineate the mechanism underlying carvacrol's gastroprotective effects, entailing augmented endogenous prostaglandin production and heightened mucus secretion. Additionally, carvacrol exerts anti-inflammatory effects by mitigating TNF-α production and modulating COX-2 antioxidant activity.
Notably, thyme oil emerges as a subject of investigation for its therapeutic potential in conditions such as Crohn's disease and ulcerative colitis. Experimental studies featuring thymol administration in young pigs unveil alterations in gene expression pertinent to cell division regulation and stomach digestion, thus underscoring its prospective therapeutic relevance.7
FAQs
How should thyme supplements be taken?
Thyme supplements are available in various forms, including capsules, teas, and tinctures. The recommended dosage and administration instructions may vary depending on the specific product and intended use.
Are there any potential side effects or interactions with thyme?
While thyme is generally considered safe for most individuals when consumed in culinary amounts, excessive intake or use of thyme supplements may lead to potential side effects such as allergic reactions, digestive upset, or interactions with certain medications.
Is thyme safe for pregnant or breastfeeding women?
Pregnant or breastfeeding women should exercise caution when using thyme supplements or essential oils, as safety data regarding their use during pregnancy and lactation is limited. It's advisable to consult with a healthcare provider before incorporating thyme into the diet or using it medicinally during pregnancy or while breastfeeding.
References
- Thyme | cooking, medicinal, aromatic | britannica [Internet]. [cited 2024 Feb 13]. Available from: https://www.britannica.com/plant/thyme
- Nieto G. A review on applications and uses of thymus in the food industry. Plants (Basel) [Internet]. 2020 Jul 30 [cited 2024 Feb 13];9(8):961. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7464319/
- National Institute of Diabetes and Digestive and Kidney Diseases [Internet]. [cited 2024 Feb 13]. Your digestive system & how it works - niddk. Available from: https://www.niddk.nih.gov/health-information/digestive-diseases/digestive-system-how-it-works
- Hammoudi Halat D, Krayem M, Khaled S, Younes S. A focused insight into thyme: biological, chemical, and therapeutic properties of an indigenous mediterranean herb. Nutrients [Internet]. 2022 May 18 [cited 2024 Feb 13];14(10):2104. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9147557/
- Almanea A, El-Aziz GSA, Ahmed MMM. The potential gastrointestinal health benefits of thymus vulgaris essential oil: a review. Biomed Pharmacol J [Internet]. 2019 Dec 31 [cited 2024 Feb 15];12(04):1793–9. Available from: http://biomedpharmajournal.org/vol12no4/the-potential-gastrointestinal-health-benefits-of-thymus-vulgaris-essential-oil-a-review/
- [cited 2024 Feb 15]. Available from: https://www.google.com.pk/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&ved=2ahUKEwj9vtfM7K2EAxU6hP0HHSVLAlIQFnoECCQQAQ&url=https%3A%2F%2Fwww.ema.europa.eu%2Fen%2Fdocuments%2Fherbal-summary%2Fthyme-oil-summary-public_en.pdf&usg=AOvVaw11S4-CDfOwR8pGu6iLaMYd&opi=89978449
- [cited 2024 Feb 15]. Available from: https://www.google.com.pk/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&ved=2ahUKEwiq773O7a2EAxVf_7sIHT3CBIUQFnoECBUQAQ&url=https%3A%2F%2Fjournals.innovareacademics.in%2Findex.php%2Fajpcr%2Farticle%2Fdownload%2F26759%2F15634&usg=AOvVaw1TQS-kx4ZmgC5x2ATKTLkT&opi=89978449
