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The American Heritage Dictionary defines '''essential oil''' as:
{{TOC|right}}
<blockquote>
<p style="margin-left: 2.0%; margin-right: 6%; font-size: 1.0em; font-family: Gill Sans MT, Trebuchet MS;"> A volatile oil, usually having the characteristic odor or flavor of the plant from which it is obtained, used to make perfumes and flavorings.<ref>The American Heritage® Dictionary of the English Language, Fourth Edition. Copyright© 2006, 2000 by Houghton Mifflin Company. Published by Houghton Mifflin Company.</ref></p>
</blockquote>


Familiar examples of essential oils include those extracted from species of citrus, lavender, seeds of celery and pumpkin, eucalyptus, and rosewood.
'''Essential oils''' are [[hydrophobic]], concentrated oils derived from the leaves, seeds, barks, roots or rinds of various plants, and containing volatile chemicals with strong smells.  Familiar examples of essential oils include those extracted from citrus, lavender, seeds of celery and pumpkin, eucalyptus, and rosewood. Known essential oils number in the hundreds.  Some are valued for [[Aromatherapy|aromatherapy]], some (but not all) are appropriate for topical use, that is, direct skin application, and some are used in perfumes and flavorings.   Some have antimicrobial properties. Per McGill university, the 'essential' in their name refers to the fact that the oils contains the ''essence'' of a plant, its fragrance.<ref>[https://www.mcgill.ca/oss/article/health-you-asked/are-all-oils-essential-are-essential-oils-even-oils Are All Oils Essential? Are Essential Oils Even Oils?] from McGill University's Office for Science and Society </ref>
 
In addition to their use in perfumes and flavorings, essential oils have been used in complementary and alternative medicine as antimicrobials.  Microbiologists Hammer and colleagues studied the ''in vitro'' antimicrobial activity of 52 essential oils, reporting as follows:
 
<blockquote>
<p style="margin-left: 2.0%; margin-right: 6%; font-size: 1.0em; font-family: Gill Sans MT, Trebuchet MS;"> In summary, this study confirms that many essential oils and plant extracts possess ''in vitro'' antibacterial and antifungal activity. However, if plant oils and extracts are to be used for food preservation or medicinal purposes, issues of safety and toxicity will need to be addressed.<ref name=hammer1999> Hammer KA, Carson CF, Riley TV. (1999) [http://dx.doi.org/10.1046/j.1365-2672.1999.00780.x Antimicrobial activity of essential oils and other plant extracts]. ''J Appl Microbiol'' 86:985-90. PMID 10438227</ref></p>
</blockquote>
 
==Aromatherapy==
The odoriferous quality of essential oils lends itself to the practice called [[aromatherapy]], wherein the inhalation of the odors of an oil may yield positive health effects of various types. The National Cancer Institute (NCI), linked through the National Center for Complementary and Alternative Medicine (NCCAAM), provides the following overview of aromatherapy for health professional:
 
*Aromatherapy is the therapeutic use of essential oils (also    known as volatile oils) from plants (flowers, herbs, or trees) for the    improvement of physical, emotional, and spiritual well-being.
*Aromatherapy is used by patients with cancer primarily    as supportive care for general well-being.
*Aromatherapy is used with other complementary treatments (e.g., massage and acupuncture) as well as standard treatment.
*Essential oils are volatile liquid substances extracted from aromatic plant material by steam    distillation or mechanical expression; oils produced with the aid of    chemical solvents are not considered true essential     oils.
*Essential oils are available in the United States for inhalation and topical treatment. Topical treatments are    generally used in diluted forms.
*Aromatherapy is not widely administered via ingestion.
*The effects of aromatherapy are theorized to result    from the effect of odorant molecules from essential oils on the brain’s    emotional center, the limbic system. Topical application of    aromatic oils may exert antibacterial, anti-inflammatory, and analgesic effects.
*Studies in animals show sedative and stimulant effects of specific essential oils    as well as positive effects on behavior and the immune system. Functional imaging studies in humans support    the influence of odors on the limbic system and its emotional pathways.
*Human clinical trials have investigated aromatherapy    primarily in the treatment of stress and anxiety in patients with critical    illnesses or in other hospitalized patients. Several clinical trials    involving patients with cancer have been published.
*Aromatherapy has a relatively low toxicity profile when administered by    inhalation or diluted topical application.
*Aromatherapy products do not need approval by the U.S. Food and Drug Administration because    there is no claim for treatment of specific diseases.
*Repeated exposure to lavender and tea tree oils by    topical administration has been associated with reversible prepubertal    gynecomastia.
 
 
 
<!-- An '''essential oil''' - [[liquid]] [[extraction|extracts]] from [[plant]]s, which are called aromatic herbs or aromatic [[plant]]s and from some other materials (as lichens, honey etc.). This pressed, [[Distillation|distilled]] or extracted substances containing [[Volatile (chemistry)|volatile]] [[aroma compound]]s, mainly [[hydrophobic]] ([[terpene]]s, [[terpeniod]]s, [[benzene]] derivates (aromatic compounds), [[aldehyde]]s, [[organic acids]] etc.).
*Essential oils also known as '''volatile''' or '''ethereal''' oils, or simply as the "oil of" the plant material from which they were extracted,  such as ''oil of clove''. The traditional name '''essential oil''' indicates that the oil carries distinctive [[scent]] (essence) of the [[plant]], not that it is an especially important or fundamental substance. -->
 
<!--Essential oils do not as a group need to have any specific chemical properties in common, beyond conveying characteristic fragrances. They are not to be confused with [[essential fatty acid]]s.
 
Essential oils are generally extracted by [[distill]]ation. Other processes include expression, or [[solvent extraction]].  They are used in [[perfumes]] and [[cosmetics]], for [[flavoring]] food and drink, and for scenting [[incense]] and household [[:Category:Cleaning products|cleaning products]].
 
Various essential oils have been used medicinally at different periods in history. [[Medicinal properties|Medical applications]] proposed by those who sell medicinal oils vary from skin treatments to remedies for cancer, and are often based on historical use of these oils for these purposes. Such claims are now subject to regulation in most countries, and have grown correspondingly more vague, to stay within these regulations.
 
Interest in essential oils has revived in recent decades, with the popularity of [[aromatherapy]], a branch of [[alternative medicine]] which claims that the specific aromas carried by essential oils have curative effects. Oils are volatilized or diluted in a carrier oil and used in massage, or burned as incense, for example.-->


== Production ==
== Production ==
{{main|Extraction (fragrance)}}
      
      
===Distillation===
===Distillation===
{{see also|Distillation}}
Some common essential oils, such as [[lavender]], [[peppermint]], [[tea-tree]] and [[eucalyptus]], are [[Continuous_distillation|distilled]].  Raw plant material, consisting of the [[flower]]s, [[leaf|leaves]], [[wood]], [[bark]], [[root]]s, [[seed]]s, or [[peel (fruit)|peel]], is put into an [[alembic]] (distillation apparatus) over [[water]]. As the water is heated the steam passes through the plant material, vaporizing the volatile compounds. The vapors flow through a coil where they condense back to liquid, which is then collected in the receiving vessel.
Some common essential oils, such as [[lavender]], [[peppermint]], [[tea-tree]] and [[eucalyptus]], are distilled.  Raw plant material, consisting of the [[flower]]s, [[leaf|leaves]], [[wood]], [[bark]], [[root]]s, [[seed]]s, or [[peel (fruit)|peel]], is put into an [[alembic]] (distillation apparatus) over [[water]]. As the water is heated the steam passes through the plant material, vaporizing the volatile compounds. The vapors flow through a coil where they condense back to liquid, which is then collected in the receiving vessel.
 
<!--
Most oils are distilled in a single process. One exception is [[Ylang-ylang]] ([[Cananga odorata]]), which takes 22 hours to complete through a [[Fractional distillation | fractional distillation]].
 
The water recondensed from the distillation process is referred to as a [[hydrosol]], hydrolat, [[herbal distillate]] or plant water essence, which may be sold as another fragrant product. Popular hydrosols are [[rose water]], [[lavender water]], [[lemon balm]], [[clary sage]] and [[orange blossom water]]. The use of herbal distillates in [[cosmetics]] is increasing. Some plant hydrosols have unpleasant [[smell]]s and are therefore not sold.
 
===Expression===
Most citrus peel oils are usually expressed mechanically, or ''[[cold-pressed]]''. Due to the large quantities of oil in citrus peel and the relatively low cost to grow and harvest the raw materials, citrus-fruit oils are cheaper than most other essential oils. Lemon or sweet orange oils that are obtained as [[by-product]]s of the commercial citrus industry are even cheaper.
 
Prior to the discovery of [[distillation]], some essential oils (EO) were extracted by pressing.
 
===Solvent extraction===
Most flowers contain very little volatile oil to undergo expression and their chemical components are too delicate and easily denatured by the high heat used in steam distillation.  Instead, a [[solvent]] such as [[hexane]] or [[supercritical carbon dioxide]] is used to extract the oils.  Extracts from hexane and other hydrophobic solvent are called ''[[Concrete (perfumery)|concrete]]s'', which is mixture of essential oil, waxes, resins, and other [[lipophilic]] (oil soluble) plant material.
 
Although highly fragrant, concretes contain large quantities of non-fragrant waxes and resins. As such another solvent, often [[ethanol|ethyl alcohol]], which only dissolves the fragrant low-molecular weight compounds, is used to extract the fragrant oil from the concrete. The alcohol is removed by a second distillation, leaving behind the ''[[Absolute (substance)|absolute]]''.
 
[[Supercritical carbon dioxide]] is used as a solvent in supercritical fluid extraction. This method has many benefits, including avoiding [[petrochemical]] residues in the product. It does not yield an absolute directly. The supercritical carbon dioxide will extract both the waxes and the essential oils that make up the concrete.  Subsequent processing with liquid carbon dioxide, achieved in the same extractor by merely lowering the extraction temperature, will separate the waxes from the essential oils.  This lower temperature process prevents the decomposition and denaturing of compounds and provides for a superior product. When the extraction is complete, the pressure is reduced to ambient and the carbon dioxide reverts back to a gas, leaving no residue. Although supercritical carbon dioxide is also used for making [[decaffeinated]] [[coffee]], the actual process is different.
 
===Production quantities===


Estimates of total production of essential oils are difficult to obtain. One estimate, compiled from data in 1989, 1990 and 1994 from various sources gives the following total production, in tonnes, of essential oils for which more than 1,000 tonnes were produced.<ref>{{cite web
| url=http://isotc.iso.org/livelink/livelink/971087/ISO_TC_054__Essential_oils_.pdf
| title=ISO TC 54 Business Plan &mdash; Essential oils
| accessdate=2006-09-14
}} It is unclear from the source what period of time the quoted figures include.</ref>
:{| class="wikitable"
! Oil !! Tonnes
|-
| [[Sweet orange]] || align="right" | 12,000
|-
| ''[[Mentha arvensis]]'' || align="right" | 4,800
|-
| [[Peppermint]] || align="right" | 3,200
|-
| [[Cedar|Cedarwood]] || align="right" | 2,600
|-
| [[Lemon]] || align="right" | 2,300
|-
| ''[[Eucalyptus globulus]]'' || align="right" | 2,070
|-
| ''[[Litsea cubeba]]'' || align="right" | 2,000
|-
| [[Clove]] (leaf) || align="right" | 2,000
|-
| [[Spearmint]] || align="right" | 1,300
|}
-->
==Aromatherapy==
==Aromatherapy==
{{main|Aromatherapy}}
{{main|Aromatherapy}}  
<!--
Aromatherapy is a form of [[complementary and alternative medicine]], in which healing effects are ascribed to the aromatic compounds in essential oils and other plant extracts.  Many common essential oils have medicinal properties that have been applied in [[folk medicine]] since ancient times and are still widely used today.  For example, many essential oils have [[antiseptic]] properties, though some are stronger than others.<ref>{{cite journal
Aromatherapy is a form of [[alternative medicine]], in which healing effects are ascribed to the aromatic compounds in essential oils and other plant extracts.  Many common essential oils have medicinal properties that have been applied in [[folk medicine]] since ancient times and are still widely used today.  For example, many essential oils have [[antiseptic]] properties, though some are stronger than others.<ref>{{cite journal
  | url=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&rendertype=abstract&artid=1693916
  | url=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&rendertype=abstract&artid=1693916
  | title=In vitro antibacterial activity of some plant essential oils
  | title=In vitro antibacterial activity of some plant essential oils
Line 131: Line 43:
  | accessdate-2006-12-24
  | accessdate-2006-12-24
  | id=PMID 16095639
  | id=PMID 16095639
}}</ref> and unconfirmed in others.<ref>{{cite journal
}}</ref> and unconfirmed in others.
 
The odoriferous quality of essential oils lends itself to the practice called [[aromatherapy]], wherein the inhalation of the odors of an oil may yield positive health effects of various types.  In some respects, assessing its benefits are more difficult than with other forms of complementary medicine: whether or not the essential oils actually give benefit, they smell much better than the average hospital.
 
===Uses===
Some of the clinical trials that are more suggestive of benefits have two characteristics:
*Aromatherapy is complementary to medical therapy<ref>{{citation
| journal = Breast Cancer Res. | year = 2007 | volume = 9(Suppl 2) | page= S9.
| date = 20 December 2007 | doi =  10.1186/bcr1807.
| title = Benefits of complementary therapies
| author = Caroline Hoffman
| url = http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2230517/
}}</ref>
*Aromatherapy is complementary to other complementary therapies: it may, for example, be effective in combination with massage but not on its own.<ref>{{citation
  | journal = Journal of Clinical Oncology | volume = 25 | issue =  5 | date = 10 February 2007 | pages = 532-539
| doi = 10.1200/JCO.2006.08.9987
| title = Effectiveness of Aromatherapy Massage in the Management of Anxiety and Depression in Patients With Cancer: A Multicenter Randomized Controlled Trial
| author = Susie M. Wilkinson, Sharon B. Love, Alex M. Westcombe, Maureen A. Gambles, Caroline C. Burgess, Anna Cargill, Teresa Young, E. Jane Maher, Amanda J. Ramirez
| url = http://jco.ascopubs.org/content/25/5/532.long
}}</ref>
 
Skin application, not necessarily massage, have been tested as more effective than inhalation alone. Another study suggested that applying the oils to the skin may be more effective than inhalation. <ref name=>{{citation
|  journal = Altern Complement Med
| date = 2004 Jun
| volume = 10(3)
| pages  =431-7.
| title= A controlled trial of aromatherapy for agitation in nursing home patients with dementia.
  | author = Snow LA, Hovanec L, Brandt J. | url = http://www.ncbi.nlm.nih.gov/pubmed/15253846}}</ref> Massage may be of greater benefit than either inhalation or simple application. <ref>{{cite journal
  | url=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&rendertype=abstract&artid=1142199
  | url=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&rendertype=abstract&artid=1142199
  | title=Immunological and Psychological Benefits of Aromatherapy Massage
  | title=Immunological and Psychological Benefits of Aromatherapy Massage
Line 143: Line 82:
}}</ref>
}}</ref>


== Dilution ==
Training in aromatherapy does not convey additional diagnostic skill.  <ref name=UKselect-Ch2>{{citation
| url = http://www.parliament.the-stationery-office.co.uk/pa/ld199900/ldselect/ldsctech/123/12302.htm
| author = Select Committee appointed to consider Science and Technology, U.K. Parliament
| contribution = Chapter 2: Disciplines examined, Definitions of the Various CAM Therapies
| title = Complementary and Alternative Medicine
| date = 21 November 2000
}}</ref>


Essential oils are usually [[lipophilic]] (literally: ''"oil-loving"'') compounds that usually are not [[miscible]] with water. Instead, they can be diluted in [[solvent]]s like pure 100% [[ethanol]] (''alcohol''), [[polyethylene glycol]], or [[oil]]s.
The National Cancer Institute (NCI), linked through the National Center for Complementary and Alternative Medicine (NCCAAM), provides the following overview of aromatherapy for health professional:
-->
== Raw materials ==
{{main|List of essential oils}}
<!--
Essential oils are derived from various sections of plants. Some, like [[Orange (fruit)|orange]] oil, are derived from any of several sections of the plant.


:{| class="wikitable" |
*Aromatherapy is the therapeutic use of essential oils (also    known as volatile oils) from plants (flowers, herbs, or trees) for the    improvement of physical, emotional, and spiritual well-being.
| valign="top" |
*Aromatherapy is used by patients with cancer primarily    as supportive care for general well-being.
'''<big>[[Berry|Berries]]</big>'''
*Aromatherapy is used with other complementary treatments (e.g., massage and acupuncture) as well as standard treatment.
 
*Essential oils are volatile liquid substances extracted from aromatic plant material by steam    distillation or mechanical expression; oils produced with the aid of    chemical solvents are not considered true essential    oils.
* [[Allspice]]
*Essential oils are available in the United States for inhalation and topical treatment. Topical treatments are    generally used in diluted forms.
* [[Juniper]]
*Aromatherapy is not widely administered via ingestion.
 
*The effects of aromatherapy are theorized to result    from the effect of odorant molecules from essential oils on the brain’s    emotional center, the limbic system. Topical application of    aromatic oils may exert antibacterial, anti-inflammatory, and analgesic effects.
'''<big>[[Seed]]s</big>'''
*Studies in animals show sedative and stimulant effects of specific essential oils    as well as positive effects on behavior and the immune system. Functional imaging studies in humans support    the influence of odors on the limbic system and its emotional pathways.
 
*Human clinical trials have investigated aromatherapy    primarily in the treatment of stress and anxiety in patients with critical    illnesses or in other hospitalized patients. Several clinical trials    involving patients with cancer have been published.
* [[Almond]]
*Aromatherapy has a relatively low toxicity profile when administered by    inhalation or diluted topical application.
* [[Anise]]
*Aromatherapy products do not need approval by the U.S. Food and Drug Administration because    there is no claim for treatment of specific diseases.
* [[Celery]]
*Repeated exposure to lavender and tea tree oils by    topical administration has been associated with reversible prepubertal    gynecomastia.
* [[Cumin]]
===Toxicity===
* [[Nutmeg oil]]
Several common essential oils, such as cinnamon and clove, can cause skin burns if applied in undiluted form. <ref>{{citation
 
| author = Ernst, E.
'''<big>[[Bark]]</big>'''
  | title = Adverse effects of herbal drugs in dermatology
 
  | journal = British Journal of Dermatology
* [[Cassia]]
  | volume = 143
* [[Cinnamon]]
  | issue = 5
* [[Sassafras]]
  | url = http://dx.doi.org/10.1046/j.1365-2133.2000.03822.x
 
  | doi = 10.1046/j.1365-2133.2000.03822.x
'''<big>[[Wood]]</big>'''
 
* [[Camphor]]
* [[Cedar]]
* [[Rosewood]]
* [[Sandalwood]]
 
'''<big>[[Rhizome]]</big>'''
 
* [[Ginger]]
 
| valign="top" |
'''<big>[[Leaf|Leaves]]</big>'''
 
* [[Basil]]
* [[Bay leaf]]
* [[Cinnamon]]
* [[Common sage]]
* [[Eucalyptus]]
* [[Lemon grass]]
* [[Melaleuca]]
* [[Oregano]]
* [[Patchouli]]
* [[Peppermint]]
* [[Pine]]
* [[Rosemary]]
* [[Spearmint]]
* [[Tea tree]]
* [[Thyme]]
* [[Wintergreen]]
 
'''<big>[[Resin]]</big>'''
 
* [[Frankincense]]
* [[Myrrh]]
 
| valign="top" |
'''<big>[[Flower]]s</big>'''
 
* [[Chamomile]]
* [[Clary sage]]
* [[Clove]]
* [[Geranium]]
* [[Hyssop]]
* [[Jasmine]]
* [[Lavender]]
* [[Manuka]]
* [[Marjoram]]
* [[Orange (fruit)|Orange]]
* [[Rose]]
* [[Ylang-ylang]]
 
'''<big>[[Peel (fruit)|Peel]]</big>'''
 
* [[Bergamot orange|Bergamot]]
* [[Grapefruit]]
* [[Lemon]]
* [[Lime (fruit)|Lime]]
* [[Orange (fruit)|Orange]]
* [[Tangerine]]
 
'''<big>[[Root]]</big>'''
 
* [[Valerian (herb)|Valerian]]
|}
 
=== Rose oil ===
{{main|Rose oil}}
The most well-known essential oil is probably [[rose oil]], produced from the petals of  ''[[Rosa damascena]]'' and ''[[Rosa centifolia]]''. Steam-distilled rose oil is known as "rose otto" while the solvent extracted product is known as "rose absolute".
 
== Dangers ==
Because of their concentrated nature, EOs generally should not be applied directly to the skin in their undiluted or "neat" form. Some can cause severe irritation or provoke an allergic reaction.  Instead, essential oils should be blended with a vegetable carrier oil (also referred to as a base or "fixed" oil) before being applied. Common carrier oils include olive, almond, hazelnut and grapeseed. Common ratio of essential oil disbursed in a carrier oil is 0.5&ndash;3% (most less than 10%) and depends on its purpose. Some EO's including many of the [[citrus]] peel oils, are photosensitizers, increasing the skin's reaction to sunlight and making it more likely to burn.
 
Industrial users of essential oils should consult the [[material safety data sheet]]s (MSDS) to determine the hazards and handling requirements of particular oils.
 
A Database of over 400 Essential Oil material safety data sheets can be accessed through the Liberty Natural Products Website: [http://libertynatural.com/msd/Msdlist.htm Liberty Natural Products MSDS Database]
 
=== Gynaecomastia ===
Some essential oils, particularly [[lavender]] and [[tea tree oil]], have been implicated in causing [[gynaecomastia]], an abnormal breast tissue growth, in prepubescent boys.
<ref>{{cite journal
|title=Prepubertal gynecomastia linked to lavender and tea tree oils
  |url=http://content.nejm.org/cgi/content/abstract/356/5/479
  |journal=New England Journal of Medicine
  |volume=356
  |issue=5
|pages=479-85
|year=2007
|pmid=17267908}}</ref>
A child hormone specialist at the [[University of Cambridge]] claimed "... these oils can mimic [[oestrogen]]s" and "people should be a little bit careful about using these products". <ref>{{cite news
  | url=http://news.bbc.co.uk/2/hi/health/6318043.stm
| publisher=BBC News
| date=February 1, 2007
| accessdate=2007-09-09
| title=Oils make male breasts develop}}</ref>
 
=== Pesticide residues ===
There is some concern about [[pesticide]] residues in EOs, particularly those used therapeutically.  For this reason, many practitioners of aromatherapy choose to buy [[Organic farming|organically]] produced oils.
 
;Ingestion
While some advocate the ingestion of essential oils for therapeutic purposes, this should never be done except under the supervision of a professional who is licensed to prescribe such treatment.  Some very common EOs such as Eucalyptus are extremely toxic internally. [[Pharmacopoeia]] standards for medicinal oils should be heeded. EOs should always be kept out of the reach of children. Some oils can be toxic to some domestic animals, [[cat]]s in particular. Owners must ensure that their pets do not come into contact with potentially harmful essential oils.<ref>{{cite journal
  | url=http://www.vet-task-force.com/Abstract-tea-tree-oil.htm
| title=Australian tea tree (Melaleuca alternifolia) Oil Poisoning in three purebred cats
| journal=Journal of Veterinary Diagnostic Investigation
| author=K. Bischoff, F. Guale
| volume=10
| issue=108
| date=1998
| accessdate=2006-10-17
}}</ref>
}}</ref>
 
==Other treatments==
Clove oil is commonly used in dentistry, to reduce tooth and gum pain.


=== Smoke ===
==Attribution==
The smoke from burning essential oils may contain potential [[carcinogen]]s, such as [[polycyclic aromatic hydrocarbons]] (PAHs). Essential oils are naturally high in [[volatile organic compound]]s (VOCs). The internal use of essential oils should be fully avoided during pregnancy without consulting with a licensed professional, as some can be [[abortifacient]]s in dose 0.5&ndash;10 ml.
{{WPAttribution}}
 
=== Toxicology ===
[[LD50|LD<sub>50</sub>]] of most EO's or their main components are 0.5-10 g/kg (orally or skin test).{{Fact|date=February 2007}}
 
== Media ==
In 2006, the German movie ''[[Perfume: The Story of a Murderer]]'' was made on the subject of essential oils.  The story takes place in France in the 1700's.
-->
 
== Notes and references ==
<references/>
<!--
=== Additional references ===


* {{cite book
==References==
| author=Kurt Schnaubelt
{{Reflist|2}}[[Category:Suggestion Bot Tag]]
| title=Advanced Aromatherapy: The Science of Essential Oil Therapy
| publisher=Healing Arts Press
| year=1999
| isbn= 0-89281-743-7
}}
* {{cite book
| author=Wanda Sellar
| title=The Directory of Essential Oils
| location=Essex
| publisher=The C.W. Daniel Company, Ltd
| edition=Reprint
| year=2001
| isbn= 0-85207-346-1
}}
* {{cite book
| author=Robert Tisserand
| title=Essential Oil Safety: A Guide for Health Care Professionals
| publisher=Churchill Livingstone
| year=1995
| isbn= 0-443-05260-3
}}
-->

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Essential oils are hydrophobic, concentrated oils derived from the leaves, seeds, barks, roots or rinds of various plants, and containing volatile chemicals with strong smells. Familiar examples of essential oils include those extracted from citrus, lavender, seeds of celery and pumpkin, eucalyptus, and rosewood. Known essential oils number in the hundreds. Some are valued for aromatherapy, some (but not all) are appropriate for topical use, that is, direct skin application, and some are used in perfumes and flavorings. Some have antimicrobial properties. Per McGill university, the 'essential' in their name refers to the fact that the oils contains the essence of a plant, its fragrance.[1]

Production

Distillation

Some common essential oils, such as lavender, peppermint, tea-tree and eucalyptus, are distilled. Raw plant material, consisting of the flowers, leaves, wood, bark, roots, seeds, or peel, is put into an alembic (distillation apparatus) over water. As the water is heated the steam passes through the plant material, vaporizing the volatile compounds. The vapors flow through a coil where they condense back to liquid, which is then collected in the receiving vessel.

Aromatherapy

For more information, see: Aromatherapy.

Aromatherapy is a form of complementary and alternative medicine, in which healing effects are ascribed to the aromatic compounds in essential oils and other plant extracts. Many common essential oils have medicinal properties that have been applied in folk medicine since ancient times and are still widely used today. For example, many essential oils have antiseptic properties, though some are stronger than others.[2]. In addition, many are claimed to have an uplifting effect on the mind, though different essential oils have different properties. The claims are supported in some studies[3][4] and unconfirmed in others.

The odoriferous quality of essential oils lends itself to the practice called aromatherapy, wherein the inhalation of the odors of an oil may yield positive health effects of various types. In some respects, assessing its benefits are more difficult than with other forms of complementary medicine: whether or not the essential oils actually give benefit, they smell much better than the average hospital.

Uses

Some of the clinical trials that are more suggestive of benefits have two characteristics:

  • Aromatherapy is complementary to medical therapy[5]
  • Aromatherapy is complementary to other complementary therapies: it may, for example, be effective in combination with massage but not on its own.[6]

Skin application, not necessarily massage, have been tested as more effective than inhalation alone. Another study suggested that applying the oils to the skin may be more effective than inhalation. [7] Massage may be of greater benefit than either inhalation or simple application. [8]

Training in aromatherapy does not convey additional diagnostic skill. [9]

The National Cancer Institute (NCI), linked through the National Center for Complementary and Alternative Medicine (NCCAAM), provides the following overview of aromatherapy for health professional:

  • Aromatherapy is the therapeutic use of essential oils (also known as volatile oils) from plants (flowers, herbs, or trees) for the improvement of physical, emotional, and spiritual well-being.
  • Aromatherapy is used by patients with cancer primarily as supportive care for general well-being.
  • Aromatherapy is used with other complementary treatments (e.g., massage and acupuncture) as well as standard treatment.
  • Essential oils are volatile liquid substances extracted from aromatic plant material by steam distillation or mechanical expression; oils produced with the aid of chemical solvents are not considered true essential oils.
  • Essential oils are available in the United States for inhalation and topical treatment. Topical treatments are generally used in diluted forms.
  • Aromatherapy is not widely administered via ingestion.
  • The effects of aromatherapy are theorized to result from the effect of odorant molecules from essential oils on the brain’s emotional center, the limbic system. Topical application of aromatic oils may exert antibacterial, anti-inflammatory, and analgesic effects.
  • Studies in animals show sedative and stimulant effects of specific essential oils as well as positive effects on behavior and the immune system. Functional imaging studies in humans support the influence of odors on the limbic system and its emotional pathways.
  • Human clinical trials have investigated aromatherapy primarily in the treatment of stress and anxiety in patients with critical illnesses or in other hospitalized patients. Several clinical trials involving patients with cancer have been published.
  • Aromatherapy has a relatively low toxicity profile when administered by inhalation or diluted topical application.
  • Aromatherapy products do not need approval by the U.S. Food and Drug Administration because there is no claim for treatment of specific diseases.
  • Repeated exposure to lavender and tea tree oils by topical administration has been associated with reversible prepubertal gynecomastia.

Toxicity

Several common essential oils, such as cinnamon and clove, can cause skin burns if applied in undiluted form. [10]

Other treatments

Clove oil is commonly used in dentistry, to reduce tooth and gum pain.

Attribution

Some content on this page may previously have appeared on Wikipedia.

References

  1. ↑ Are All Oils Essential? Are Essential Oils Even Oils? from McGill University's Office for Science and Society
  2. ↑ Seenivasan Prabuseenivasan, Manickkam Jayakumar, and Savarimuthu Ignacimuthu (November 30, 2006). "In vitro antibacterial activity of some plant essential oils". BMC Complement Altern Med. 6 (39). DOI 10.1186/1472-6882-6-39. Retrieved on 2006-12-22.
  3. ↑ Komiya M, Takeuchi T, Harada E (September 25, 2006). "Lemon oil vapor causes an anti-stress effect via modulating the 5-HT and DA activities in mice". Behav Brain Res 172 (2): 240-9. PMID 16780969. Retrieved on 2006-12-24.
  4. ↑ Hiroko Kuriyama, Satoko Watanabe, Takaaki Nakaya, Ichiro Shigemori, Masakazu Kita, Noriko Yoshida, Daiki Masaki, Toshiaki Tadai, Kotaro Ozasa, Kenji Fukui, and Jiro Imanishi (September 15, 2005). "Ambient odors of orange and lavender reduce anxiety and improve mood in a dental office". Physiol Behav 86 (1-2): 92-5. PMID 16095639.
  5. ↑ Caroline Hoffman (20 December 2007), "Benefits of complementary therapies", Breast Cancer Res. 9(Suppl 2): S9., DOI:10.1186/bcr1807.
  6. ↑ Susie M. Wilkinson, Sharon B. Love, Alex M. Westcombe, Maureen A. Gambles, Caroline C. Burgess, Anna Cargill, Teresa Young, E. Jane Maher, Amanda J. Ramirez (10 February 2007), "Effectiveness of Aromatherapy Massage in the Management of Anxiety and Depression in Patients With Cancer: A Multicenter Randomized Controlled Trial", Journal of Clinical Oncology 25 (5): 532-539, DOI:10.1200/JCO.2006.08.9987
  7. ↑ Snow LA, Hovanec L, Brandt J. (2004 Jun), "A controlled trial of aromatherapy for agitation in nursing home patients with dementia.", Altern Complement Med 10(3): 431-7.
  8. ↑ Lehrner J, Marwinski G, Lehr S, Johren P, Deecke L (June 2005). "Immunological and Psychological Benefits of Aromatherapy Massage". Evid Based Complement Alternat Med 2 (2). DOI:10.1093/ecam/neh087. Retrieved on 2006-12-24. Research Blogging.
  9. ↑ Select Committee appointed to consider Science and Technology, U.K. Parliament (21 November 2000), Chapter 2: Disciplines examined, Definitions of the Various CAM Therapies, Complementary and Alternative Medicine
  10. ↑ Ernst, E., "Adverse effects of herbal drugs in dermatology", British Journal of Dermatology 143 (5), DOI:10.1046/j.1365-2133.2000.03822.x
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