Aromatherapy is a complementary therapy that uses plant extract essential oils that are either inhaled, used as a massage oil, or occasionally ingested. It can be used to alleviate specific symptoms or as a relaxant.¹ It is based on the healing properties of the essential oils.²

The concentrated oils are aromatic and volatile. They are extracted, usually by steam distillation, from flowers, leaves, roots, grasses, peel, resin or bark. There are over 400 essential oils extracted from plants all over the world. Popular oils used include chamomile, lavender, rosemary and tea tree.³ Aromatherapy carrier oils are used for mixing blends of essential oils in order to make bath oils or massage oils. They are mainly extracted from nuts and seeds. Examples are sweet almond oil, evening primrose oil and black seed oil.

Plant oil application through massage is the most common way that aromatherapy is delivered. Aromatherapy massage uses techniques to relieve tension within the body and improve circulation. The belief is that molecules can pass through the skin and be absorbed into the bloodstream, so exerting nervous system effects.²

Inhaling the aroma of the oils is also thought to enhance wellbeing.² A few drops of oil can be added to a bath of warm water. Inhaling the oils is not recommended for asthmatics.

History

Aromatherapy has been used in various forms for thousands of years and references to such treatment may be found in texts of ancient Egypt, India and China. A French chemist called René-Maurice Gattefossé coined the term aromatherapy in the early 20th century to describe the process of using plant oils therapeutically. There is a story that while he was working in a perfume factory, he burnt his hand and swiftly put some lavender oil on the burn. He was so impressed by how quickly and cleanly the burn healed, he began to study the healing powers of plant oils.

Mechanism of action

It is thought that inhaled or dermally applied essential oils may enter the bloodstream and exert psychological effects.⁴

A study looked at psychological, autonomic, endocrine, and immune consequences of one purported relaxant odour (lavender), one stimulant odour (lemon), and a no-odour control (water), before and after a stressor (cold pressor).⁵ It found that lemon oil enhances positive mood compared with water and lavender. It also found that noradrenaline (norepinephrine) levels following the cold pressor remained elevated when subjects smelled lemon, compared with water or lavender. In the study, odours did not reliably alter interleukin-6 (IL-6) and IL-10 production, salivary cortisol, heart rate or blood pressure, skin barrier repair following tape stripping, or pain ratings following the cold pressor.

There is anecdotal evidence that lavender oil assists relaxation. Another recent study showed that expectancies, not aroma, explain the impact of lavender aromatherapy on psychophysiological indices of relaxation in young healthy women.⁶ It concluded that the previous associations of lavender aroma with assisted relaxation may have been influenced by expectancy biases, and that the relevant expectancies are easily manipulable.

Suitable conditions

Aromatherapy can help to promote relaxation.² It is currently widely used in the management of:⁴

• Chronic pain
• Depression
• Anxiety
• Some cognitive disorders
• Insomnia
• Stress-related disorders

It has also been used in the treatment of:

• Headaches
• Asthma
• Eczema
• Digestive problems
• Menstrual or menopausal problems
• Pain relief during labour

People may be treated by an aromatherapist, or they can buy certain aromatherapy oils over the counter at pharmacies, health shops and other outlets and treat themselves. An aromatherapist will probably massage oils into the skin. For self-treatment they may be added to a bath or inhaled using steaming water, a diffuser or an incense burner. There is also a wide range of toiletries containing essential oils.

Essential oils are volatile and flammable. They should never be used near an open flame. The essential oils sold in shops are often mislabelled and dosage may be unreliable.

Use of complementary and alternative medicines

There has been considerable interest in complementary and alternative medicine (CAM) with a House of Lords Select Committee Report in November 2000.¹

In the UK, 47% of people have used CAM at some time in their lives and 10% use some form of CAM each year.⁷ Users tend to be older and female, and over 90% is purchased outside of the NHS. At least 10% of hospital physicians also use CAM as part of their clinical practice.⁸ A survey conducted in 2001 estimated that one in two practices in England now offer their patients some access to CAM.⁹

Aromatherapy is increasing in popularity but some of this is not so much for the management of specific complaints as people buying something with a pleasant aroma to enhance the pleasure of a relaxing bath.

The consultation³

The aromatherapist will usually discuss a person's medical history, general health and lifestyle. This will help him or her to decide which essential oils are most appropriate to use. After selecting and blending appropriate essential oils, the aromatherapist will usually use massage to apply the oils.

A session normally lasts for 60 to 90 minutes.

Cautions and contra-indications¹⁰

• Diabetics should avoid angelica.
• Epileptics should avoid fennel, rosemary and sage (because of the risk of over-stimulating the nervous system).
• Hypertensives should avoid hyssop, rosemary, sage and thyme.
• Pregnant ladies should avoid basil, laurel, angelica, thyme, cumin, aniseed, citronella and juniper. An aromatherapist should always be alerted if the patient is pregnant because of potential teratogenic and uterine effects of the oils.
• Sensitive skins should avoid basil, laurel, coriander, tea tree, neroli, geranium, mint, yarrow, Roman and German chamomile, lemon balm, citronella, ginger, hops, jasmine, lemon, lemon grass (unless greatly diluted with a carrier oil), turmeric and valerian. Skin patch testing can be carried out beforehand if there are concerns. Care should be taken in those with a history of allergy or atopic conditions such as asthma, eczema or hayfever.
• Oestrogen-dependent tumours such as breast cancer or ovarian cancer, are a contra-indication to the use of oils with oestrogen-like compounds such as fennel, aniseed, sage, and clary-sage.
• There may be possible interactions of essential oils, with antibiotics, antihistamines and sedatives.
• Cinnamon, turmeric, valerian, laurel, juniper, aniseed, coriander and eucalyptus should not be used for longer than two weeks at a time because of concerns about toxicity.
• Bitter almond, red thyme, common sage, rue, wormwood, tansy, savory, wintergreen and sassafras oils should be avoided at all times by everyone as they can be poisonous.

Adverse effects

• Side-effects can include allergic reactions (including rash), headache and nausea.
• A report in the New England Journal of Medicine concluded that prepubertal gynaecomastia in three boys was linked to exposure to lavender and tea tree oils.¹¹ However, this was strongly criticised and there were calls for the article to be retracted.¹²
• There may also be a problem of sensitisation to the essential oils for the aromatherapists themselves which can result in occupational contact dermatitis.¹³

Evidence

It can be very difficult to extract the differences that may be due to the pleasant aromas, relaxation and physical touch of aromatherapy from any other health benefit.
One UK study looking at the impact of CAM on health outcomes called for those evaluating impact to use standardised tools to improve the overall quality of the studies.¹⁴

Pain management in labour

• A Cochrane review looked at complementary and alternative therapies (including aromatherapy) for pain management in labour.¹⁵ The outcome measures were maternal satisfaction, use of pharmacological pain relief and maternal and neonatal adverse outcomes. There was only one trial involving aromatherapy in the review with few participants. It showed no difference in outcome in the aromatherapy group. The conclusion was that more research is needed.
• A pilot randomised controlled trial (RCT) looked at the use of aromatherapy during childbirth.¹⁶ It found that pain perception was reduced in the aromatherapy group for nulliparae. However, the trial was underpowered.

Psychiatric disorders

• A review concluded that aromatherapy may provide a potentially effective treatment for a range of psychiatric disorders. It also noted the safety of aromatherapy when compared with conventional psychotropic drugs. It called for more research into this area.⁴
• Another recent paper highlighted that there have been some promising results which suggest that further research is warranted to investigate the potential of essential oils in treating anxiety, depression and symptoms of stress.¹⁷
• A further review highlighted that there is currently minimal empirical evidence for the use of aromatherapy in the treatment of anxiety and depression.¹⁸ However, the review concluded that this lack of evidence does not reduce the popularity of CAM within the general western population.

Dementia

• Another Cochrane review looked at the use of aromatherapy in people with dementia. It found that there may be a possible effect on agitation and neuropsychiatric symptoms.¹⁹ However, it stated that more well-designed RCTs were needed before any firm conclusions could be drawn.
• A more recent review of the evidence also looked at the use of aromatherapy to treat behavioural and psychological problems in dementia.²⁰ Eleven studies (most with small numbers of participants) were included. The review reported that data supporting the efficacy of aromatherapy are scarce; available studies reported positive and negative consequences, both for people with dementia and their carers. It also stated that the side-effect profile of commonly used oils is virtually unexplored. The conclusion was that "although a potentially useful treatment for behavioural and psychological problems, the expectations of clinicians and patients with respect to the efficacy and tolerability of conventional medicines should equally apply to aromatherapy".

General reviews

• A review in the British Journal of General Practice in 2000 found 12 trials of aromatherapy.²¹ It concluded that:
  • The studies suggested that aromatherapy massage has a mild, transient anxiolytic effect.
  • The effects of aromatherapy are probably not strong enough for it to be considered for the treatment of anxiety.
  • The hypothesis that it is effective for any other indication is not supported by the findings of rigorous clinical trials.
• Focus group interviews in one study looked at how aromatherapists feel about changing their practice through undertaking an RCT. It concluded that participating in an RCT does impact on aromatherapists' holistic practice but equally important is their commitment to undertake the research.²²

Alopecia

• Some studies have shown potential benefit of aromatherapy in alopecia.²³
• However, this is disputed in robust meta-analysis.^24,25

Multiple sclerosis

• Another study showed promise in the use of complementary therapy (including aromatherapy) by persons with multiple sclerosis. Again, more research was called for.²⁶

Regulation of aromatherapists

• The House of Lords Select Committee was keen on the regulation of all forms of CAM.¹
• The Aromatherapy Council is the lead or governing body for the UK aromatherapy profession. Currently, regulation and registration of complementary therapists in the UK is voluntary self-regulation.
• Two regulatory bodies have been established. The first is the General Regulatory Council for Complementary Therapists (GRCCT). The second is the Complementary and Natural Healthcare Council (CNHC). The links to their websites can be found below.
• To ensure that aromatherapists not registered with one of these bodies are not disadvantaged in any way, the Aromatherapy Council has set up a way of checking qualifications of aromatherapists, on their education and training page (please refer to website link below). An aromatherapist who holds a recognised qualification and is a full member of one of the associations within the Aromatherapy Council is permitted to state that they are AC Recognised.

Document references

1. Sixth Report. Complementary and Alternative Medicine, House of Lords Select Committee on Science and Technology, November 2000
2. Complementary medicine: information pack for primary care groups, Dept of Health, June 2000
3. Aromatherapy Council
4. Perry N, Perry E; Aromatherapy in the management of psychiatric disorders: clinical and neuropharmacological perspectives. CNS Drugs. 2006;20(4):257-80. [abstract]
5. Kiecolt-Glaser JK, Graham JE, Malarkey WB, et al; Olfactory influences on mood and autonomic, endocrine, and immune function. Psychoneuroendocrinology. 2008 Apr;33(3):328-39. [abstract]
6. Howard S, Hughes BM; Expectancies, not aroma, explain impact of lavender aromatherapy on psychophysiological indices of relaxation in young healthy women. Br J Health Psychol. 2008 Nov;13(Pt 4):603-17. Epub 2007 Sep 7. [abstract]
7. Thomas KJ, Nicholl JP, Coleman P; Use and expenditure on complementary medicine in England: a population based survey. Complement Ther Med. 2001 Mar;9(1):2-11. [abstract]
8. Lewith GT, Hyland M, Gray SF; Attitudes to and use of complementary medicine among physicians in the United Kingdom. Complement Ther Med. 2001 Sep;9(3):167-72. [abstract]
9. Thomas KJ, Coleman P, Nicholl JP; Trends in access to complementary or alternative medicines via primary care in England: 1995-2001 results from a follow-up national survey. Fam Pract. 2003 Oct;20(5):575-7. [abstract]
10. Safe Alternative Medicine. Expert advice on alternative medicine. Accessed February 2009
11. Henley DV, Lipson N, Korach KS, et al; Prepubertal gynecomastia linked to lavender and tea tree oils. N Engl J Med. 2007 Feb 1;356(5):479-85. [abstract]
12. Attia Ltd; response to gynecomastia allegations: Prepubertal gynaecomastia linked to Lavender and Tea Tree Oil (2007); Call for the Journal of New England Medicine to publish a retraction
13. Trattner A, David M, Lazarov A; Occupational contact dermatitis due to essential oils. Contact Dermatitis. 2008 May;58(5):282-4. [abstract]
14. Wye L, Sharp D, Shaw A; The impact of NHS based primary care complementary therapy services on health BMC Complement Altern Med. 2009 Mar 6;9:5. [abstract]
15. Smith CA, Collins CT, Cyna AM, et al; Complementary and alternative therapies for pain management in labour. Cochrane Database Syst Rev. 2003;(2):CD003521. [abstract]
16. Burns E, Zobbi V, Panzeri D, et al; Aromatherapy in childbirth: a pilot randomised controlled trial. BJOG. 2007 Jul;114(7):838-44. Epub 2007 May 16. [abstract]
17. van der Watt G, Janca A; Aromatherapy in nursing and mental health care. Contemp Nurse. 2008 Aug;30(1):69-75. [abstract]
18. van der Watt G, Laugharne J, Janca A; Complementary and alternative medicine in the treatment of anxiety and depression. Curr Opin Psychiatry. 2008 Jan;21(1):37-42. [abstract]
19. Thorgrimsen L, Spector A, Wiles A, et al; Aroma therapy for dementia. Cochrane Database Syst Rev. 2003;(3):CD003150. [abstract]
20. Nguyen QA, Paton C; The use of aromatherapy to treat behavioural problems in dementia. Int J Geriatr Psychiatry. 2008 Apr;23(4):337-46. [abstract]
21. Cooke B, Ernst E; Aromatherapy: a systematic review. Br J Gen Pract. 2000 Jun;50(455):493-6. [abstract]
22. Kyle G, Marks-Maran D; Focus group interviews: how aromatherapists feel about changing their practice through undertaking a randomised controlled trial? Complement Ther Clin Pract. 2008 Aug;14(3):204-11. Epub 2008 Mar 6. [abstract]
23. Hay IC, Jamieson M, Ormerod AD; Randomized trial of aromatherapy. Successful treatment for alopecia areata. Arch Dermatol. 1998 Nov;134(11):1349-52. [abstract]
24. Delamere FM, Sladden MM, Dobbins HM, et al; Interventions for alopecia areata. Cochrane Database Syst Rev. 2008 Apr 16;(2):CD004413. [abstract]
25. van den Biggelaar FJ, Smolders J, Jansen JF; Complementary and alternative medicine in alopecia areata. Am J Clin Dermatol. 2010;11(1):11-20. doi: 10.2165/11530040-000000000-00000. [abstract]
26. Esmonde L, Long AF; Complementary therapy use by persons with multiple sclerosis: benefits and research priorities. Complement Ther Clin Pract. 2008 Aug;14(3):176-84. Epub 2008 May 7. [abstract]

Internet and further reading

• The General Regulatory Council for Complementary Therapies (GRCCT)
• Complementary and Natural Healthcare Council (CNHC)