Heliotherapy
How can heliotherapy nourish you?
Heliotherapy derives its name from ‘helios’, the Greek word for sun, and is defined as the therapeutic use of sunlight. The sun is critical to human survival, and mankind relies on it to provide warmth and nurture plants for nourishment. In addition to physical sustenance, sunlight is key in helping to regulate our internal sleep-wake cycle, known as our circadian rhythm, which is essential for optimal health[1].
Heliotherapy is the precursor of light therapy or phototherapy but is distinct from those modalities in its use of natural sunlight instead of man-made lamps. Heliotherapy’s effectiveness is a result of the sun’s ultraviolet (UV) rays, with the UVA and UVB rays being used as treatments for different conditions in various concentrations. UVB rays are also absorbed and converted by the body to Vitamin D, an essential ingredient for physical health and emotional well-being.
While sunlight as a therapeutic force was used by ancient civilizations[2], heliotherapy as a scientific modality was first discovered by Danish Nobel prize winner Niels Ryberg Finsen[3] in the 1890s. He observed the effects of sunlight on his health conditions, which led to conducting clinical trials for the use of sunlight in smallpox and tuberculosis. Its effectiveness and success led to Finsen being awarded the Nobel Prize for his innovative investigation of light therapy in 1903.
A tailored regime and controlled exposure to the sun is essential in heliotherapy, with over-exposure to ultraviolet rays being ill-advised. Even the location of the sun exposure could play a role – in the 20th century, the Dead Sea was a popular place for heliotherapy[4] due to its low sea level providing an extra layer of filtration from UV rays. With increasing evidence of the positive impact that sunlight can have on our health, some medical professionals are now advocating for a revised approach to sun exposure, and calling moderate exposure “necessary for public health[5]”.
Benefits of heliotherapy
A well-known effect of sunlight and one benefit of heliotherapy is that it can increase vitamin D levels[6], a vitamin essential for optimal bone health[7] and one being investigated for its potential to assist other health conditions.
In the early 20th century, heliotherapy was widely used as a treatment for tuberculosis[8] until antibiotic treatment was developed. These days, it is still used as a treatment for chronic skin conditions. It has been the most widely researched for its use in conditions such as psoriasis[9] and atopic dermatitis, with heliotherapy described as helping to significantly clear psoriasis symptoms in a majority of patients[10]. A study that prescribed heliotherapy alongside lifestyle advice found that a two-week course of treatment improved symptoms of psoriasis and atopic dermatitis, with improvements lasting up to three months later[11]. Those with atopic dermatitis also reported enhanced quality of life.
Exposure to sunlight is known to assist the optimal functioning of our circadian rhythm, which can help to stabilise one’s metabolism and weight. Sunlight also causes the production of melatonin, which in turn assists with inducing sleep[12]. Research reports that those exposed to sunlight or very bright light earlier in the morning commence melatonin production earlier, aiding sleep at night and assisting with insomnia as well as symptoms of premenstrual syndrome[13].
Sunlight can also help people to feel happier due to its impact on serotonin production[14] and therefore has been used to help those experiencing seasonal affective disorder[15]. With heliotherapy as the precursor to bright light therapy, the use of light to influence mood is now commonplace and often prescribed for mood disorders such as depression and bipolar disorder[16].
Heliotherapy may assist in relieving symptoms related to:
What to expect from a heliotherapy session?
Heliotherapy has the distinct advantage of being a very accessible therapy, given the naturally occurring availability of sunlight. It is also a simple therapy to engage in, involving simply the exposure of your skin to sunlight. Your practitioner should provide you with instructions as to how much of your skin you should expose to the sunlight, the time of the day you should do it, and for how long. It may not need to be done every single day and is generally recommended in the early morning or the evening and for short periods of time[17].
Depending on your situation, heliotherapy may also be prescribed alongside other therapies, medication, or vitamins. For instance, heliotherapy may be used as a treatment for mood[18] by your psychiatrist. Alternatively, it may be recommended by your dermatologist as a treatment for a skin condition[19]. The effects of heliotherapy are also unlikely to be immediate, given it works at a cellular level.
Given there are risks related to excessive exposure to sunlight[20], heliotherapy should always be performed according to your practitioner’s instructions. As with any exercise or wellness program, please consult your medical professional before commencing heliotherapy. If you have an injury or other health issue, or any concerns at all, also speak to your practitioner, who will be happy to address these and personalise the treatment regime to suit your requirements.
References
1. Bryan L, Bryan L. Circadian rhythm. Sleep Foundation; 2024.
2. Gupta, Nishant & Gusain, Poonam. Ancient Light Therapies: A Boon To Medical Science. Science and Culture; 2018.
3. Alpert JS. The Jeremiah Metzger Lecture: Jeremiah Metzger and the Era of Heliotherapy. Trans Am Clin Climatol Association; 2015.
4. Heliotherapy. DermNet®; [cited on 2024 Nov 27].
5. Baggerly CA, Cuomo RE, French CB, Garland CF, Gorham ED, Grant WB, et al. Sunlight and vitamin D: necessary for public health. Journal of the American College of Nutrition; 2015.
6. Vestita M, Filoni A, Congedo M, Foti C, Bonamonte D. Vitamin D and atopic dermatitis in childhood. Journal of Immunology Research; 2015.
7. Vitamin D and your health: Breaking old rules, raising new hopes. Harvard Health; 2021.
8. Sunshine: Clinical Friend or Foe? The American Journal of Medicine; 2010.
9. Roth E. Sun and Psoriasis: Benefits and Risks. Healthline; 2022.
10. Heliotherapy. ScienceDirect; [cited on 2024 Nov 27].
11. Karppinen T, Ylianttila L, Kautiainen H, Reunala T, Snellman E. Empowering heliotherapy improves clinical outcome and quality of life of psoriasis and atopic dermatitis patients. Acta Dermato Venereologica; 2014.
12. Sleep. The Royal Women’s Hospital; [cited on 2024 Nov 27].
13. Mead MN. Benefits of sunlight: A bright spot for human health. Environmental Health Perspectives; 2008.
14. What are the benefits of sunlight? Healthline; 2019.
15. Campbell PD, Miller AM, Woesner ME. Bright Light Therapy: Seasonal Affective Disorder and Beyond. Einstein J Biol Med; 2017.
16. Choukroun J, Geoffroy PA. Light Therapy in Mood Disorders: A Brief History with Physiological Insights. Chronobiology in Medicine; 2019.
17. Peters B MD. How getting sunlight in the morning can help you sleep better. Verywell Health; 2024.
18. Meldon M. Healing with heliotherapy. Crownview Medical Group; [cited on 2024 Nov 27].
19. Light therapy for psoriasis. NYU Langone Health; [cited on 2024 Nov 27].
20. Causes of skin cancer. Cancer Council; [cited on 2024 Nov 27].