Synthetic vitamin E may be culprit behind vaping lung injuries, says investigators
According to a paper, vitamin E acetate may have been used as a cutting agent in samples taken from 51 patients with electronic-cigarette, or vaping, product use–associated lung injury (EVALI).
The study coincides with the 2400 hospitalised patients reported in 25 US states to date, in which some had used THC-containing products that tested positive for vitamin E acetate, a chemical sometimes used as a thickening agent in illegal THC-containing products.
While the lung injuries seen in the US are unrelated to the nicotine replacement e-cigarette devices sold in UK high streets, the authors also point out that increased nicotine salt exposure may also be detrimental to health.
“These studies provide further evidence that the outbreak of serious lung disease among vapers in the USA this year was caused by vaping THC, and may particularly be due to vaping THC solutions containing vitamin E acetate,” says professor John Britton, director of the UK Centre for Tobacco & Alcohol Studies and consultant in respiratory medicine at the University of Nottingham.
“The conclusions provide strong reassurance that people vaping nicotine as an alternative to tobacco smoking are unlikely to be affected, and should continue to vape instead of smoke.”
Prior to the outbreak in the US, 12 cases linked to nicotine-containing e-cigarettes were flagged to the UK’s Medicines and Healthcare products Regulatory Agency (MHRA).
European authorities have not reported any serious medical problems related to vaping products except one in 2015 that was related to e-cigarettes documented in Spain.
As US authorities strongly suspect illicit THC-cartridges as well as the use of e-cigarette vape products as the most likely cause of EVALI, Europe points to THC’s illegal status in European countries as the prime reason behind a significantly lower EVALI rate in Europe despite increasing e-cigarette use.
Vitamin E acetate
Writing in the New England Journal of Medicine, the team from the National Center for Environmental Health describe the safety of inhaling vitamin E acetate as receiving ‘little attention’.
Vitamin E acetate is commonly used as a dietary supplement and in skin creams. It is found in multivitamins and is enzymatically cleaved to vitamin E during absorption.
Previously, the ingestion and dermal application of vitamin E acetate have not generally been associated with adverse health effects.
The team go in to highlight a number of trade websites that report its addition, along with medium-chain triglycerides to THC-containing products, as a way enhance their quality and appearance, provide desirable aroma or taste, and lower product cost.
“The new findings provide further robust confirmation that EVALI is caused by contaminants in illegal THC (cannabis) cartridges,” says professor Peter Hajek, director of the Tobacco Dependence Research Unit at the Queen Mary University of London. “Among a group of 51 confirmed and ‘probable’ cases, 94% vaped cannabis.”
“A particularly informative finding is that out of 11 patients who denied using cannabis, 9 had THC in their system and the remaining three were ‘probable’ EVALI cases that the authors suggest have been misdiagnosed. (One had drug overdose (and S. aureus), one was re-diagnosed with coccidioidomycosis and one had S. aureus pneumonia). The anti-vaping fear-mongering should now be put to rest.”
Similar viscosity
While pure THC oil has a viscosity like that of vitamin E acetate, cutting THC oil with vitamin E acetate is considered common in the illicit market.
In October last year, the Food and Drug Administration (FDA) reported that out of 494 samples containing THC, 50% of the THC products contained vitamin E acetate as a diluent.
In contrast, the paper also states the FDA detected no vitamin E acetate in 197 case-associated nicotine products analysed to date.
“The viscosity of vitamin E acetate makes it undesirable as an additive to nicotine solutions; the propylene glycol and vegetable glycerin in nicotine solutions create a fluid with a much lower viscosity than that of vitamin E acetate,” the paper notes.
“The key message is that the comparative risks of tobacco cigarettes (with over 7000 different chemicals in each cigarette) are still significantly higher than e-cigarettes,” says Jacob George, professor of cardiovascular medicine and therapeutics, University of Dundee
“Non-smokers should not try e-cigarettes but tobacco smokers could switch to e-cigarettes as a harm reduction measure.”
Source: New England Journal of Medicine
Published online: doi: 10.1056/NEJMoa1916433
“Vitamin E Acetate in Bronchoalveolar-Lavage Fluid Associated with EVALI.”
Authors: Blount BC et al.
