What is heliotherapy
Heliotherapy is a medical science that uses the beneficial effects on the body of exposure to sunlight. The influence of the sun on health is profound: sunlight records the various biological rhythms (sleep and wake, for example) and influences the optimal function of the metabolism, promotes the activation of vitamin D and stimulates the immune system, hormonal and many physiological and biochemical reactions of the organism.
Exposure modalities and times
The time of exposure to sunlight can vary from 15 minutes to an hour, depending on the subjective sensitivity of the skin to solar radiation (example: subjects with a light phototype, with dark complexion etc.) and the type of disorder for which resort to heliotherapy. Furthermore, the hours of maximum solar intensity are generally avoided.
Avoid overexposure!
It is essential to be able to correctly measure exposure to solar radiation so that it is not violent: the time intervals should be short and repeated, also depending on the disorder to be treated.
Precautions
Here are some practical tips for those who want to take advantage of this healthy source of energy and limit potential side effects:- Avoid sunbathing from 11 to 15
- Schedule outdoor activities early in the morning or late afternoon
- Wear sunglasses (protect from ultraviolet light) and adequate headgear.
- Pay attention to reflective surfaces: water, snow and sand on the beach reverberate radiation up to 80-90%.
- Apply a sunscreen with a sun protection factor (SPF) all over the skin at least 30 minutes before sunbathing.
Regardless of the sensitivity of your skin, avoid excessive sun exposure, especially if you are taking drugs or supplements containing photosensitising active ingredients (which, activated by the sun, can cause photosensitivity reactions, increasing the risk of sunburn). Some of these drugs they are: tetracyclines, sulfonamides, diuretics, corticosteroids, sedatives and some laxatives.
Avoid:
- taking photosensitizing drugs (antibiotics, oral contraceptives and medicines to control hypertension);
- the use of photosensitizing medicinal plants such as hypericum and imperatory;
- drugs used specifically for psoriasis that include products for topical use, calcipotriene (a derivative of vitamin D), and tazarotene (a derivative of vitamin A);
- perfumes (some ingredients can cause the formation of skin spots).
Warning!
As mentioned above, it is important to inform your doctor and / or dermatologist before starting heliotherapy, in order to identify any interactions and combinations of drugs and / or supplements that can expose you to burns or other negative reactions
Side effects
The sun can be useful for the treatment of many skin diseases, but it can also cause damage to the skin. UV-A and UV-B radiations cause tanning and sunburn: UV-B rays scald the skin faster, but penetrate less deeply than UV-A.
The damage of excessive exposure can also be serious:
- sun spots, rashes and burns;
- premature aging of the skin;
- heat stroke;
- eye disorders (example: long-term exposure to UV rays can cause eye damage such as cataract or conjunctivitis);
- induction of melanoma formation (skin cancer).
"Soltriol", the light hormone: vitamin D for short
Ultraviolet rays activate the production of vitamin D, a fundamental component for maintaining a healthy osteo-articular and immune system.
The sun reaches the skin, stimulating the reaction that causes the 7-dehydrocholesterol pro-hormone to become pre-vitamin D3, which is then metabolised to vitamin D3. This form is transported through the bloodstream, from the skin to the liver and then to the kidneys, where it becomes a biologically active hormone (1, 25-dihydroxyvitamin D3) which promotes calcium reabsorption in the kidney, calcium absorption and phosphorus, and the processes of mineralization of the bone matrix (curiosity: this substance in its active form is sometimes called "soltriol", light hormone).
Final considerations
Heliotherapy highlights the impact light has on health: if implemented wisely, this natural technique can be exploited to benefit both in the prevention and treatment of many pathological conditions.
