Essential oils
Essential oils (also called aromatherapy oils due to their distinctive strong scents) are highly concentrated plant extracts made by heating the plants and collecting the steam that is produced (distillation). These liquids are used widely in the cosmetic, fragrance, and food industries and also may have medical and neuroactive properties. In fact, essential oils have been used therapeutically around the world for centuries. For medical treatments, these oils are usually inhaled or are diluted significantly in water or carrier oil and rubbed on the skin.

Until recently, there was little published research examining the effectiveness of these oils. However, this is changing rapidly—many clinical studies are underway in Europe, Australia, Asia, and North America. Published research now describes positive effects for a variety of health concerns including pain, anxiety, depression, menstrual cramps, and more. For example, peppermint has been used to relieve nausea. Orange and lavender have been used to reduce anxiety and boost people’s moods.

One intriguing study examined the effects of hand massage with essential oils on pain, anxiety, and depression on patients with late-stage cancer. All patients received a five-minute hand massage each day for seven days. Half of these patients received the massage with a blend of bergamot (an Italian citrus), lavender, and frankincense essential oils, while the other half received the massage with no aromatherapy oils. The group who received the hand massage with essential oils reported significantly less pain and depression than the control group (Chang et al 2008). A similar study examined the effects of massage with essential oils on college students with severe menstrual cramps (Han et al 2006). In this study, women were randomly placed into one of three treatments: relaxation, abdominal massage with almond oil, or abdominal massage with almond oil and lavender, clary sage, and rose essential oils. The women in the aromatherapy group reported significantly less menstrual cramp pain than women in other groups. Because these studies both used a control group (massage with no aromatherapy oil), they clearly demonstrate that the reductions in pain, depression, and menstrual cramps are from the aromatherapy oils rather than from the massage itself.

Aromatherapy oils have also been used as stimulants and depressants. Recent research (Haze et al 2002) examined the effects of essential oils on the sympathetic nervous system in normal adults by looking at fluctuations in blood pressure, heart rate, and plasma levels of adrenaline and noradrenaline, two hormones released as part of the fight or flight response. Six different essential oils were examined: pepper, grapefruit, estragon (from the tarragon plant), fennel, patchouli (a member of the mint family), and rose. People in the study inhaled either the essential oil dissolved in an odorless solvent, or the odorless solvent alone for three minutes. Results suggest that inhaling pepper, estragon, fennel, or grapefruit oil increased the activity of the sympathetic nervous system significantly (blood pressure and heart rate increased, with adrenaline concentrations increasing significantly in the pepper oil group). In contrast, inhaling rose or patchouli oil resulted in approximately a 40% decrease in sympathetic activity and a 30% decrease in adrenaline concentrations.