I keep thinking of how EOs specifically could help us in this pandemic when the organism needs a strong immune system – let’s say phenol-rich oils? Or perhaps antioxidant EOs are not necessarily the best choice of EOs in regard to immunity? Do you have any comments on essential oils and immunity?
Thanks a lot!
Hi Nina. I’m going for a bit longer answer as this may be relevant for other students too.
There are several components to your question: immunostimulant, antioxidant, antiviral and anti-inflammatory activity. These are all different types of activity with different mechanisms. There has been a lot of speculation regarding immune stimulation with essential oils. To be honest, I haven’t seen convincing evidence yet. People often over-interpret in vitro studies or mix anti-inflammatory, antimicrobial and antioxidant activities with immune-boosting and a strong immune system, which causes confusion.
Several EOs are antiviral, but no such activity has been confirmed specifically for the SARS-CoV-2, except for some computational studies which are far from conclusive. In mice, 1,8-Cineole was able to reduce an influenza-induced inflammatory over-reaction (cytokine storm) which is partially shared with Covid-19 pathology. 1,8-Cineole reduced inflammatory mediators, including interferon-gamma, and new research suggests that interferons directly upregulate the ACE2 receptors used by the coronavirus to enter the cell. But it would be a long stretch to then assume that 1,8-cineole, or other anti-inflammatory agents (EO or non-EO), could play a clinically significant role in this regard. Usually things are more complex than they seem, and there are many approaches to tackle the coronavirus and/or the damage it causes. We just don’t know yet what really works.
Phenols are excellent antioxidants as well as great antibacterial agents, but their antiviral activity is not that well described. They may be too aggressive for the systemic treatment of severe acute inflammation, and not specific enough for prevention.
Specific immune system ‘boosting’ on the other hand is very rare in the plant kingdom, and this has evolutionary reasons as most plants are food for mammals, not something we’re fighting and sharpening our immune systems against. Even the well-known traditional immune stimulant herbs such as Echinacea (purple coneflower) had mixed results in systematic reviews of clinical trials. However, there is good evidence of immune stimulation for beta-glucans – polysaccharides from the cell walls of certain fungus species. Glucans structurally resemble components of pathogens, which is why they activate our immune cells (including those in the gut lymphatic system) without causing harm.
Apart from that, and more importantly, the best thing you can do for your immune system is to exercise regularly, eat healthy food (also make sure you have enough vitamin C and D3, and zinc), get good quality sleep, avoid stress and stay well hydrated. All of these are proven to help optimize the immune system.
Petra Ratajc is a biologist with a post-graduate education in medicinal and aromatic plants, secondary plant metabolites, pharmacology and pharmacognosy. She obtained her PhD from Biological and Biotechnical Sciences from the University of Ljubljana, researching the quality, safety and efficacy of local aromatic herbs and their essential oils. Her research experience extends from fieldwork to molecular research, and her main interests are the biology and pharmacology of plant volatile constituents. Petra runs an educational site The PhytoVolatilome. For the past few years, she has been engaged in the field of aromatic plants and extracts as a lecturer, as well as a seminar and workshop presenter.