Lavender

The lavenders (Lavandula) are a genus of 39 species of flowering plants in the mint family, Lamiaceae. An Old World genus, distributed from Macaronesia (Cape Verde and Canary Islands and Madeira) across Africa, the Mediterranean, South-West Asia, Arabia, Western Iran and South-East India. It is thought the genus originated in Asia but is most diversified in its western distribution.

The genus includes annuals, herbaceous plants, subshrubs, and small shrubs. The native range extends across the Canary Islands, North and East Africa, Southern Europe and the Mediterranean, Arabia and India. Because the cultivated forms are planted in gardens worldwide, they are occasionally found growing wild as garden escapees, well beyond their natural range. However, since lavender cross-pollinates easily, there are countless variations within the species. The color of the flowers of some forms has come to be called lavender.

Uses

The most common "true" species in cultivation is the common lavender Lavandula angustifolia (formerly L. officinalis). A wide range of cultivars can be found. Other commonly grown ornamental species are L. stoechas, L. dentata, and L. multifida.

The lavandins Lavandula × intermedia are a class of hybrids of L. angustifolia and L. latifolia. The lavandins are widely cultivated for commercial use, since their flowers tend to be bigger than those of English lavender and the plants tend to be easier to harvest, but lavandin oil is regarded by some to be of a lower quality than that of English lavender, with a perfume less sweet.

Culinary use

Flowers also yield abundant nectar from which bees make a high-quality honey. Monofloral honey is produced primarily around the Mediterranean, and is marketed worldwide as a premium product. Flowers can be candied and are sometimes used as cake decorations. Lavender flavors baked goods and desserts (it pairs especially well with chocolate), and is also used to make "lavender sugar". Lavender flowers are occasionally blended with black, green, or herbal tea, adding a fresh, relaxing scent and flavour.

Though it has many other traditional uses in southern France, lavender is not used in traditional southern French cooking. In the 1970s, a herb blend called herbes de Provence usually including lavender was invented by spice wholesalers, and lavender has more recently become popular in cookery.

Lavender lends a floral and slightly sweet flavor to most dishes, and is sometimes paired with sheep's-milk and goat's-milk cheeses. For most cooking applications the dried buds (also referred to as flowers) are used, though some chefs experiment with the leaves as well. Only the buds contain the essential oil of lavender, from which the scent and flavour of lavender are best derived.

The French are also known for their lavender syrup, most commonly made from an extract of lavender. In the United States, both French lavender syrup and dried lavender buds are used to make lavender scones and marshmallows.

Medicinal use

Lavender is used extensively with herbs and aromatherapy.

English lavender (Lavandula angustifolia) yields an essential oil with sweet overtones, and can be used in balms, salves, perfumes, cosmetics, and topical applications. Lavandin, Lavandula × intermedia (also known as Dutch lavender), yields a similar essential oil, but with higher levels of terpenes including camphor, which add a sharper overtone to the fragrance. Mexican lavender, Lavandula stoechas is not used medicinally, but mainly for landscaping.

Essential oil of lavender has antiseptic and anti-inflammatory properties. It was used in hospitals during World War I to disinfect floors and walls. These extracts are also used as fragrances for bath products.

According to folk wisdom, lavender has many uses. Infusions of lavender soothe and heal insect bites and burns. Bunches of lavender repel insects. If applied to the temples, lavender oil soothes headaches. In pillows, lavender seeds and flowers aid sleep and relaxation. An infusion of three flowerheads added to a cup of boiling water soothes and relaxes at bedtime. Lavender oil (or extract of Lavender) heals acne when used diluted 1:10 with water, rosewater, or witch hazel; it also treats skin burns and inflammatory conditions.^{[citation needed]}

A recent clinical study investigated anxiolytic effects and influence on sleep quality. Lavender oil with a high percentage of linalool and linalyl acetate, in form of capsules, was generally well tolerated. It showed meaningful efficacy in alleviating anxiety and related sleep disturbances.

Health precautions

These remedies should be used with caution since lavender oil can also be a powerful allergen.

Avoid ingesting lavender during pregnancy and breastfeeding.

In vitro, lavender oil is cytotoxic. It increases photosensitivity as well. Lavender oil is cytotoxic to human skin cells in vitro (endothelial cells and fibroblasts) at a concentration of 0.25%. Linalool, a component of lavender oil, may be its active component. Aqueous extracts reduced mitotic index, but induced chromosomal aberrations and mitotic aberrations in comparison with control, significantly. Aqueous extracts induced breaks, stickiness, pole deviations and micronuclei. These effects were related to extract concentrations.

However, according to a 2005 study "although it was recently reported that lavender oil, and its major constituent linalyl acetate, are toxic to human skin cells in vitro, contact dermatitis to lavender oil appears to occur at only a very low frequency. The relevance of this in vitro toxicity to dermatological application of Lavandula oils remains unclear."

In terms of photoxicity, a 2007 investigative report from European researchers stated that, "Lavender oil and sandalwood oil did not induce photohaemolysis in our test system. However, a few reports on photosensitivity reactions due to these substances have been published, e.g. one patient with persistent light reaction and a positive photo-patch test to sandalwood oil."

Controversy over possible endocrine-disrupting activity

In 2007, a study was published in the New England Journal of Medicine which indicated that studies in human cell lines indicated that both lavender oil and tea tree oil had estrogenic and antiandrogenic activities. They concluded that repeated topical exposure to lavender and tea tree oils probably caused prepubertal gynaecomastia in some boys.The study has been criticised on many different levels by many authorities. The Aromatherapy Trade Council of the UK has issued a rebuttal.

The Australian Tea Tree Association, a group that promotes the interests of Australian tea tree oil producers, exporters and manufacturers issued a letter that questioned the study and called on the New England Journal of Medicine for a retraction (ATTIA).

The New England Journal of Medicine has so far not replied and has not retracted the study.

 Other uses

Flower spikes are used for dried flower arrangements. The fragrant, pale purple flowers and flower buds are used in potpourris. Lavender is also used extensively as herbal filler inside sachets used to freshen linens. Dried and sealed in pouches, lavender flowers are placed among stored items of clothing to give a fresh fragrance and to deter moths. Dried lavender flowers have become recently popular for wedding confetti. Lavender is also popular in scented waters and sachets.