Sage

Known as the ‘salvation plant’, sage is the largest member of the Lamiaceae (mint) family. Native to the Mediterranean region, common sage (Salvia officinalis) is one of over 900 species worldwide. Used as a fragrant spice in food and commercially in soaps and cosmetics, sage has a long history of use as a herbal medicine. Promoted as a digestive and nervous system tonic, and believed to enhance fertility, mental acumen, and immortality, sage has been used medicinally in numerous diseases. Alleged to stimulate menstruation, treat menorrhagia, hyperlactation, and hot flashes during menopause, sage has also been applied topically on cold sores, insect bites and stings, gargled for inflammation of the mouth, tongue and throat, and inhaled for the treatment of asthma. More recently, sage has been investigated for its potential to treat cancer, hyperlipidaemia, diabetes, cognitive impairment and Alzheimer disease.

Common sage, culinary sage, broadleaf sage, Dalmatian sage, garden sage, golden sage, kitchen sage, true sage, and others.

S. officinalis is available as a fresh or dried herb, leaf tea, extract, essential oil, liquid, powder, tincture, spray, disposable oral swab, mouth rinse, capsules, tablets and smudge sticks. Commercially sage is also found in herbal soaps, toothpaste, deodorant and a range of cosmetic products.

S. officinalis is claimed to moderate excessive sweating and hot flashes during menopause; support the airways, immunity, liver, digestive and circulatory health; facilitate wound repair; treat infected bites, stings and cuts; keep joints flexible; exert a purifying action in the mouth and throat; improve cognitive ability, thought clarity, memory, and problem solving. Smudge sticks are believed to cleanse people, objects or spaces.

The biological properties of sage are reportedly due to several compounds, including but not limited to 1,8-cineole, borneol, camphor, α-/β-thujone, rosmarinic acid, ursolic acid, α-humulene, trans-caryophyllene, carnosic acid and carsonol. Thujone and camphor are recognised as neurotoxic compounds. Sage essential oil contains higher levels of thujone than other preparations; some products are marketed as thujone free.

A wide range of studies attest to the medicinal benefits of sage. Efficacy is attributed to a range of active compounds showing antimicrobial, anti-inflammatory, antitumour, antioxidant, antinociceptive, antiangiogenic activities, and mnemonic activity.

In Alzheimer’s disease, S. officinalis extracts have been shown in vitro and in mice models to reduce acetylcholine esterase activity. Rosmarinic acid is reported to be one of several compounds that exhibits neuroprotective, antioxidant and anti-apoptotic effects, reducing oxidative stress and delaying formation and aggregation of amyloid beta fibrils. In a 4-month randomised, double-blind, placebo-controlled trial, adults taking S. officinalis showed significantly greater improvement in cognitive function measured by Alzheimer’s Disease Assessment Scale and Clinical Dementia Rating Scale. Positive cognitive and mood-enhancing effects, as well as enhancement to memory and attention, have been seen with S. officinalis; however to demonstrate benefit, larger and longer-term trials are needed.

For menopausal symptoms, a double-blind, randomised and placebo-controlled clinical trial, with 80 menopausal women experiencing ≥5 (or intense) hot flushes daily, demonstrated a significant reduction in the Menopausal Rating Scale and 55% decrease in Hot Flush Severity Score (P = 0.002 and P = 0.028 respectively) with 3400 mg S. officinalis daily by week 3. This is supported by a previous study, showing a further reduction in hot flush intensity with a longer treatment duration. In this study, the mean number of severe flushes decreased by 79% and very severe flushes decreased by 100% by week 8. Sage was also shown to significantly improve sleep quality and reduce discontent and fatigue. Hot flushes were also significantly reduced in prostate cancer patients receiving androgen deprivation therapy.

Sage has also shown some positive anti-inflammatory, antinociceptive effects, anxiolytic and bronchodilator effects, with reduction in postprandial glucose levels, total cholesterol and LDL, and improvement in HDL levels. However, human clinical data are lacking and exhibit important study limitations.

Sage is safe when consumed in quantities typically found in food; however, larger doses used in studies have been safe for up to 4 months. There have been some reports of contact dermatitis and local irritation with topical preparations, and cheilitis, stomatitis, and dry mouth following ingestion. Two cases of generalised tonic-clonic seizures were reported in a newborn and toddler following exposure to sage essential oil.

No documented interactions have been reported. Moderate caution is advised with medicines used in the treatment of Alzheimer’s such as cholinergic drugs. Due to the possible blood pressure and glucose-lowering effects, use with antihypertensive and hypoglycaemic agents should be monitored. Sage may augment the effects of benzodiazepines and central nervous system depressants and decrease the effectiveness of anticonvulsants.