Essential Oils and Plant Defenses
People use essential oils in aroma therapy, for relaxation, muscle soreness, and possibly other things.
‘Essence’ is the key word and it is not essential in the sense that it has value like found in some chemicals for body functions like iron, iodine, and potassium.
Website articles touch on essential oils as a pest repellent for things like mosquitos and do not discuss the nature niche role for protecting plants from pests that cause them harm. Evolution of essential oils has an ecological defense function that harms pestiferous organisms and helps prevent them from using the plant. In general they repel insects. Mammals are not as seriously impacted by harmful effects. Greater exception applies to cats.
Aromas from products should be used in well ventilated area but this lessons desired impact of filling the room with a chosen order such as Lavender.
Essential oils can have negative impacts for people of all ages but are especially harmful for infants and children under age ten because they have thin skin that absorbs chemicals rapidly and their livers are not fully developed to help filter chemicals.
People with respiratory issues are more highly vulnerable to harm from essential oils. Remember essential in these plants refers to “essence or smell.” Anyone that dealt with Covid-19 respiratory illness needs to be cautious of essential oils.
Some chemicals like citrus oils increase sensitivity to ultraviolet light and enhance danger to sunburn.
If used as an insect repellent, they evaporate readily requiring frequent application. It is recommended that topical use should not be used continuously but should be added at intervals of at least two hours. I expect aroma therapy applicators are at high risk for complications related to exposure. Anyone exposed for extended periods of time should consult a physician with experience or specific knowledge regarding essential oils.
Keep in mind that plants have primarily evolved essential oils as a response that protects them from certain insects. Mint, lavender, and orange oils are defensive chemicals.
When studying plant chemicals in entomology courses, the approach is greatly different than the information that appears in articles about aroma therapy.
Inhalation and application to skin can have harmful effect. Articles for medical use caution us by suggesting dilution and limited exposure. That particularly applies for children and people with compromised health issues and for people with respiratory impairment.
Essential oil can cause skin rashes. It might be good to pretend you are an insect and avoid essential oils but keep in mind they do appear not have as serious negative impacts for mammals.
Essential oils are not regulated the FDA and most testing is inconclusive regarding health benefits. Like happens with most things, people choose what they want to believe and dismiss science evidence in preference for what they desire or choose to believe.
Science is not about belief but what physical evidence supports. Controlled testing of essential oils is not well studied with controlled scientific methodology experiments.
Natural history questions or topic suggestions can be directed to Ranger Steve (Mueller) at [email protected] – Ody Brook Nature Sanctuary, 13010 Northland Dr. Cedar Springs, MI 49319 or call 616-696-1753.
Written for WORC, Feb 2021