Ear light therapy

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'''Ear light therapy''' is a [[Light woo|woo light therapy]] method, where earphone-shaped LED lights are inserted into the ear. Ear light therapy is promoted as a stimulating treatment for [[sleep]]-related conditions such as jet lag, tiredness in shiftworkers and seasonal affective disorder (SAD, a form of clinical depression caused by low levels of sunlight).<ref name="valkee">https://humancharger.com/</ref> The current [[scientific consensus]] is that it is ineffective.<ref name="evi">http://www.askforevidence.org/help/valkee-light-therapy-in-ear-device-lacking-in-evidence</ref><ref name="Bromundt2014">www.chronobiology.ch/wp-content/uploads/2013/11/bromundt_etal_2013.pdf</ref>

Despite lack of effectiveness, ear light devices are nevertheless still sold by Valkee Ltd. under than brand name HumanCharger.<ref name="valkee" /> The device was approved as a medical device in the EU; however, this simply certifies its safety, such as electrical and thermal safety, but not actual effectiveness.<ref name="ts2015">http://hyvinvointi.ts.fi/terveys-tiede/korvavalon-tehosta-ei-nayttoa/</ref>

The origin of the device is in brain research done at the University of Oulu in [[Finland]]. The retina of the [[eye]] is a type of nerve tissue, so its similarity to [[brain]] tissue is expected. In 2011, University of Oulu scientists published a finding that brain tissue contains a light-sensitive pigment called light-sensitive photoreceptor [[protein]] (Opsin-3 that is encoded by the {{wpl|OPN3}} [[gene]]).<ref name="pr">https://www.prnewswire.com/news-releases/the-human-brain-is-sensitive-to-light-breakthrough-findings-from-valkee-and-the-university-of-oulu-127506878.html</ref> This claim was based on studies of cadavers, and has not been published in a [[peer-reviewed]] journal.<ref name="evi" /> The [[hypothesis]] was that if brain tissue is photosensitive, then illuminating it could induce similar effects as illuminating the retina: relief of SAD, jetlag and tiredness. While brain tissue is difficult to access, the bone in the ear canal is thin enough that light can be directly shone through it using regular LEDs. This is a [[falsifiable]] prediction, so things didn't seem that bad as far as science goes. The company Valkee Ltd. was founded as a spin-off to manufacture the devices. Preliminary studies even tentatively indicated that in patients with SAD, there were antidepressant and anxiolytic effects. However, the studies lacked proper [[Experimental control|controls]] and there was no dose response.<ref name="Jurvelin2014">Jurvelin H, Takala T, Nissilä J, Timonen M, Rüger M, Jokelainen J, Räsänen P. Transcranial bright light treatment via the ear canals in seasonal affective disorder: a randomized, double-blind dose-response study. BMC Psychiatry. 2014 Oct 21;14:288. doi: 10.1186/s12888-014-0288-6. PubMed PMID: 25330838; PubMed Central PMCID: PMC4207317.</ref><ref name="Timonen2012">Timonen M, Nissilä J, Liettu A, Jokelainen J, Jurvelin H, Aunio A, Räsänen P, Takala T. Can transcranial brain-targeted bright light treatment via ear canals be effective in relieving symptoms in seasonal affective disorder? A pilot study. Med Hypotheses. 2012 Apr;78(4):511-5. doi: 10.1016/j.mehy.2012.01.019. Epub 2012 Jan 31. PubMed PMID: 22296809.</ref><ref name="evi" /> Other studies, however, showed that there were no actual physiological or [[psychological]] effects: [[melatonin]] levels were unchanged, subjective sleepiness was not reduced and performance was not improved.<ref name="Bromundt2014" /> Further studies by the original group showed no effect on melatonin or cortisol.<ref>Jurvelin H, Takala T, Heberg L, Nissilä J, Rüger M, Leppäluoto J, Saarela S, Vakkuri O. Transcranial bright light exposure via ear canals does not suppress nocturnal melatonin in healthy adults–a single-blind, sham-controlled, crossover trial. Chronobiol Int. 2014 Aug;31(7):855-60. doi: 10.3109/07420528.2014.916297. Epub 2014 May 14. PubMed PMID: 24828616.</ref> The proponents of the therapy tried to pooh-pooh this fact away by speculating that the effect could be mediated by the human flavoprotein CRY; there is no evidence whatsoever for this claim.<ref name="ts2015" />

Given their simple construction — a LED and a battery — the devices are rather expensive, costing 199 €. Continuing the sale of an ineffective medical device has been criticized as unethical,<ref name="ts2015" /> and has been called out as a [[scam]].<ref name="ELS">http://earlightswindle.com/gloom/2018/09/valkee-turnover-up-50-1-million-loss-as-usual/</ref>

Valkee Ltd. filed for bankruptcy in 2021. Embarrassingly, the largest creditor was the government agency Business Finland, which had granted 1.2 M€ worth of loans to Valkee for technology development and research.<ref>https://yle.fi/uutiset/3-12198716</ref>

==See also==
*[[Ear candling]] — a less bright idea

==References==
{{reflist|2|80%}}

[[Category:Sleep]]
[[Category:Woo]]

Categories: Sleep, Woo