Aromatherapy is a term first used by French chemist RM Gattefosse in 1937. It is the art and science of using aromas, especially essential oils, to treat the body, mind, and spirit. Aromatherapy is often used as a companion to herbal medicine.

Essential oils are extracted from herbs, flowers, resins, wood fibers, and plant roots. Various techniques are used in the process. In ancient Egypt, essential oils were extracted by steeping plant material in oil and then straining through linen. Today most essential oils are extracted by steam distillation.

Essential oils aren’t really oils. They are distilled condensations formed by passing steam through plant material. These "essential oils" rise with the steam and are collected. The resulting fluid is a volatile essence with molecules so small they can penetrate skin. Essential oils are massaged into the skin, inhaled, or placed in baths.

Carrier oils are used to dilute the essential oils which may otherwise cause irritation. Good carrier oils include olive oil, grape seed oil, avocado oil, almond oil, walnut oil, safflower oil, and coconut oil. The best carrier oils are cold pressed (cold pressed oils are extracted by running the vegetable material through a press). The resulting carrier oils are free of additives and chemicals.

Essential oils are a hundred times more concentrated than dried herbs. During the life of a plant, the essential oils deliver messages to regulate its functions, to protect from environmental stress, and to attract insects for pollination. These plant essences act much like hormones do in humans.

How can essential oils help heal the body? Consider the sense of smell. Smell is the most direct of all our senses. The olfactory cells in the nose are the only place in the human body where the brain is directly in contact with the external world. Smell doesn’t have to travel across millions of nerve cells to reach the brain. Scents go directly to the brain via the hypothalamus.

Scent affects our memories, emotions, moods, and hormones. Scent influences the endocrine system responsible for hormone levels, metabolism, insulin production, stress levels, sex drive, body temperature, and appetite. Scents and their effect on the human body are the main focus of aromatherapy and during the next few months this column will explore the properties of various essential oils.

* Never use essential oils on the skin without first diluting with carrier oil (there are exceptions such as lavender which may be applied neat to bug bites, scrapes, and other skin problems). Do not use in the early stages of pregnancy or on new born babies. Use only a few drops at a time. Blend only two or three different oils together at one time. Do not take essential oils internally (there are exceptions such as clove). Never use essential oils near the eyes. Do not use with candles - some essential oils may have flammable properties. Use in moderation and always monitor results. Before using essential oils, always consult with a healthcare professional especially if pregnant, nursing, or taking other medicines.