Vaping, Part 3: Combined risks - oils and TRP channel activators.
The risks of vaping may be additive, inhaling oils may increase risk of exogenous lipoid pneumonia (ELP), and inhaling TRP channel activators may increase risk of oxidative stress of cells or mitochondria. See part 1 Vaping and TRP Channel Activators, and part 2 Vaping Risks: ELP pneumonia and Oils, for the first two parts of the series.
Inhaling something accidentally is called aspirating and may occur while trying to swallow saliva, food or beverages, or during vomiting, especially for someone with weak muscles as may occur during chronic illness or with aging. Inhaling vape mixtures is purposeful and the original goal was to reduce health risks known to be associated with toxins caused by burning tobacco or an herb. Tobacco also has known carcinogens which would be removed from a product made with only the nicotine such as nicotine gums, lozenges or a nicotine patch.
Nicotine and cannabinoids can have health benefits, while toxins found in smoke can increase oxidative stress and may cause symptoms such as digestive problems, eczema, in addition to respiratory problems such as a chronic cough or bronchitis. Finding a safer way to consume nicotine or cannabinoids would be desirable however vaping may not be the solution, or not yet.
Flavorings that add odor are unnecessary for a product that isn't inhaled through the nose, but an antioxidant preservative such as vitamin E and emulsifiers* such as glycerine are added to preserve and stabilize the mixture. Safer substitutes might not be available as other substances that preserve and emulsify might affect the lungs negatively also. Air is for inhaling, not emulsifiers. Vitamin E is oil based, antioxidants that are water based are available such as vitamin C, but then how would it stay mixed with an oil based cannabinoid or nicotine which dissolves better in oil or alcohol?
Nicotine can dissolve in water better than cannabinoids (2) and original vaping mixtures were made for nicotine rather than the cannabinoids THC or CBD. Vaping devices are available for powdered herb which heat the herb at a lower temperature than burning it, the problem with that method is that some of the beneficial cannabinoids in some strains of medicinal marijuana are only produced at higher temperatures so the vaped medicine may not provide the full symptom relief that smoking the strain would provide to a patient.
Trying to remove the glycerine from a nicotine vape mixture might not be fully protective against health risks either. The risk may involve a combination of the nicotine and the glycerine, as suggested in an murine based study of e-cigarette chemicals. Chronic exposure to a mixture containing nicotine and propylene glycol** (3 weeks for 20 minutes per day) was found to slow mucociliary clearing while exposure to the propylene glycol did not. Acute exposure (one week for 20 minutes per day) to either mixture did not cause slower mucociliary clearing. The size of particles effects clearance with larger particle size being more likely to remain in the lungs and smaller particles more likely to be exhaled. (4)
Nicotine also can act as a TRP channel activator (3) so the combination of some of the flavoring chemicals or the nicotine and cannabinoids may be opening the cell membrane's TRP channels and allowing the glycerin or glycol to enter and accumulate to a level that inhibits cell function, causing Exogenous Lipoid Pneumonia or other health problems.
Pregnant women are advised to avoid use of vaped products (and to avoid smoke from tobacco or marijuana). An animal based study did find negative effects on lung alveoli development in newborn animals exposed to e-cigarette vape mixtures for the first ten days of their lives. Reduced weight gain was also noted. The negative effects were seen in the group exposed to nicotine and propylene glycol mixtures rather than the group exposed only to propylene glycol. (6)
If there is a take home point it may be that "Smoking is bad, mmmkay,"*** consider trying the nicotine patch, gum or lozenges, -- but avoiding nicotine, smoking, or vaping during pregnancy is advised.
Cannabinoids are needed for fertility for females and males in a U shape curve - too little can cause infertility and too much can cause infertility. CBD is non-euphoria causing and is equivalent to the 2-AG form that is found in greater amounts during normal health than the THC equivalent called anandamide. Neither is recommended currently for use during pregnancy however genetic differences may cause a deficiency. Chocolate and some other legal food sources are available. Non-euphoria producing cannabinoids are the most abundant in plants and are also found in human breast milk and are important for stimulating the infant's appetite and growth rate. We need cannabinoids in every cell of the body for many functions.. See the post Clinical Endocannabinoid Deficiency, (CED), and Phospholipids, for more information about symptoms or conditions that may be associated with a lack of cannabinoids and a list of legal food sources.
Footnotes:
*Glycerine is a natural emulsifier, helping to keep a water and oil mixture mixed without needing to shake it - picture an oil and vinegar salad dressing that separates into two layers compared to mayonnaise which has egg yolk as the emulsifier to keep the oil and water mixed together. (1)
** Glycerine/glycerin is also known as glycerol and glycols are similar chemically to glycerol. Some forms are more toxic to humans or animals than other forms. They are sweet syrupy liquids and may be consumed by animals if spilled in the form of antifreeze which would be toxic. (5)
*** South Park, paraphrase of a quote by the school guidance counselor Mr. Mackey.
Series:
Vaping, Part 2: ELP, Pneumonia and Oils. (This post)
Vaping, Part 3: Combined risks – oils and TRP channel activators.
Disclaimer: This information is provided for educational purposes within the guidelines of Fair Use. It is not intended to provide individual guidance. Please seek a health care provider for individualized health care guidance.
Reference List
Pat Thomas, Read the Label: Emulsifiers, TheEcologist.org, Dec 14, 2008, https://theecologist.org/2008/dec/14/read-label-emulsifiers
Nicotine, Chemistry Encyclopedia, http://www.chemistryexplained.com/Ne-Nu/Nicotine.html
Feng Z, Li W, Ward A, et al. A C. elegans model of nicotine-dependent behavior: regulation by TRP-family channels. Cell. 2006;127(3):621–633. doi:10.1016/j.cell.2006.09.035 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2859215/
Laube BL, Afshar-Mohajer N, Koehler K, et al. Acute and chronic in vivo effects of exposure to nicotine and propylene glycol from an E-cigarette on mucociliary clearance in a murine model. Inhal Toxicol. 2017;29(5):197–205. doi:10.1080/08958378.2017.1336585 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5553614/
14.6: Glycols and Glycerol, The Basics of General, Organic, and Biological Chemistry, (Ball DW, et al.) Chemistry LibreTexts, Last Updated, Aug 12, 2019 https://chem.libretexts.org/Bookshelves/Introductory_Chemistry/Book%3A_The_Basics_of_GOB_Chemistry_(Ball_et_al.)/14%3A_Organic_Compounds_of_Oxygen/14.06_Glycols_and_Glycerol
McGrath-Morrow SA, Hayashi M, Aherrera A, et al. The effects of electronic cigarette emissions on systemic cotinine levels, weight and postnatal lung growth in neonatal mice. PLoS One. 2015;10:e0118344. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4338219/