So-called wellness vapes are growing in popularity. Unlike regular vapes (e-cigarettes) that contain nicotine, these products contain vitamins, hormones or essential oils. But they have caught the attention of the US Food and Drug Administration (FDA) because of the unproven health claims made by many of the companies that sell them.

Wellness vapes – also known as “nutritional supplement diffusers” – cover a range of products that find a common origin in e-cigarettes. E-cigarettes deliver nicotine to the lungs without the need for combustion or tobacco. This removes some harmful components, such as tobacco tar. Instead of combustion, e-cigarettes use energy from a battery to heat e-liquid, which forms a vapour that can be inhaled.

A new wave of products aims to use this same inhaled delivery system for a wide range of non-nicotine products, including vitamins (B12 and C are particularly popular), milk thistle, melatonin (a hormone), green tea and a variety of essential oils. Wellness vape companies make claims that different combinations of these additives can help you focus better, promote sleep and even help you lose weight.

Inhaling rather than swallowing these compounds results in faster absorption into the bloodstream, so, theoretically, the vitamins and supplements could act faster when inhaled.

Many of these additives will be individually familiar as supplements that are rated as safe for ingestion. But the vast majority lack inhalation safety testing, particularly of potential long-term harms. Because wellness vapes don’t contain nicotine, they evade the regulators.

The incidence of e-cigarette-related acute lung injury (Evali) in the US in 2019 highlights the importance of testing the route of intake. In the 60 deaths from Evali initially reported, vitamin E acetate was identified as a key agent that caused lung damage in these people. Vitamin E is a common food additive, so this clearly highlights how even well-known substances can have very serious health consequences when inhaled.

These devices are quite new to the market, so there is little research on their safety. However, we can consider the specific components to look for potential effects, whether beneficial or harmful.

E-liquid components

Many benign or beneficial compounds can become harmful if given in an untested way or given to the wrong patient group. For example, the benefits of vitamin C are universally known, yet the use of high-dose vitamin C has been shown to increase the risk of death in people with sepsis.

Vitamin B12 is also a popular additive for these devices. In people who are deficient in the vitamin, a B12 injection is very effective in restoring levels. Yet there is a distinct lack of supporting evidence for any benefits to people with normal B12 levels. Also, we lack evidence on the safety or effectiveness of inhaled B12.

One study carried out in 1967 showed no benefit to inhaling vitamin B12 over supplementation by injection. But even in 1967, the researchers were careful to point out the potential for lung damage.

We can also look at information from shared components with e-cigarettes to look for potential effects. Some products deliver vitamin B12 dissolved in a common e-liquid component, vegetable glycerine. Other products use propylene glycol or a mixture of both liquids. When heated, these components break down into harmful chemicals, termed reactive carbonyl species, such as formaldehyde.

These chemicals have been shown to harm alveolar macrophages, important immune cells in the lung, in a way not dependent on the presence of nicotine. Similar findings have also been shown in other important airway and immune cells.

Wellness vapes delivering essential oils may also suffer from the same concerns. They contain compounds called terpenes and a mixture of other chemicals similar to e-liquids.

Terpenes have been reported to have a range of benefits including anticancer, antiallergy and antimicrobial properties, suggesting the potential benefits of taking these essential oils. However, terpenes are degraded by heat so may be broken down by vaping into harmful compounds that can irritate the airways and may be toxic to cells at higher doses and longer exposure.

Increased scrutiny

Given the similarities between e-cigarettes and wellness vapes, these companies are now facing increased scrutiny from public health bodies. The FDA has warned that wellness vapes are “unsafe”, “ineffective” and “unproven”.

We must carefully weigh the benefits and risks of use. Many of the supplements in these devices may help improve our lifestyles, but there is no evidence to support the benefits of inhalation over traditional methods of delivery.

While wellness vapes have not been around long enough for researchers to know for certain the long-term consequences of their use. We know that short-term exposure to their components can harm the lungs, so prolonged use may pose a very serious risk – one that tips the scales of evidence firmly against the use of “wellness vapes”. DM/ML

This story was first published in The Conversation.

Aaron Scott is an Asscoiate Professor in Respiratory Science at the University of Birmingham. Alice Jasper is a Postdoctoral Research Fellow in Inflammation and Ageing at the University of Birmingham. 

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