Light Therapy

Origins and historical development :

Generations of healers have been said to use the benefits of natural sunlight, most notably, 19th Century Naturopaths. Later, Doctors used incandescent electric light baths to treat a range of physical and mental illnesses for patients in sanatoriums; and also advised them to take regular exercise in bright sunlight. In 1903, The Nobel Prize for Medicine was awarded to a Danish doctor, Niels Finsen, for research into the ability of ultraviolet light to treat Tuberculosis. In the 1950’s, US Photo-Biologist Dr John Ott, discussed his research claiming that “full spectrum” light from the sun is needed by the body to absorb key nutrients. He went on to say that pollution, windows and wearing glasses may block components of the sun’s rays, vital for bodily functions. Further research into reduced daylight hours revealed a connection to severe depression. This in turn led to the recognition of Seasonal Affective Disorder (SAD), a type of depression that some people get in the winter and is thought to be caused by light deprivation.

More recently, scientists have realised the important role that light plays in regulating the body’s biorhythms. It is now known that the body has what is called ‘Circadian Rhythms’ that match the 24 hour solar day. For example, levels of Melatonin (a hormone that is involved in our sleeping patterns) and white blood cells are at their highest at night, while blood pressure and body temperature are at their highest during the day. Light stimulates nerve impulses to the brain when it enters the eyes. These nerve impulses travel to the Hypothalamus, the part of the brain responsible for temperature control, appetite, sleep, and sex drive; and the Pineal gland in the brain, which regulates hormones such as Serotonin, which is linked to mood.

In the early 1980’s, the US National Institute of Mental Health developed artificial bright light therapy for the use of treating people with SAD. Research supported exposure to the high intensity light for 2 to 6 hours daily to gain any benefit. Although there were dramatic improvements seen, it was not convenient for working people to spend so much of their time under a lamp. New lamps were developed that were more effective and needed only to be used for about 30 to 45 minutes per day. These were positioned about 30cm away from the eyes on a tilted stand, so that the light was directed downwards into the eyes, mimicking the angle that actual sunlight normally falls onto the body.

In conventional medicine, treatment using light is referred to as Phototherapy and is used to treat jaundice in newborns; as well as for the treatment of psoriasis. Phototherapy retains the UV wavelengths in the light therefore risks with Phototherapy include direct eye injury and photosensitivity. In the complementary use of Light Therapy, special lamps emit fluorescent full spectrum light that is the same as natural daylight but without the toxic UV wavelengths, as studies suggest that these are not needed for the antidepressant effect to work.

What to expect during a treatment :

Sessions will normally last for about an hour; and involve the client lying fully clothed on a couch, eyes open, under a lamp that runs the length of their body. These lamps emit bright white light of at least 2,500 lux (‘light units’) of illumination.

Treatment with Light Therapy can be carried out at home using a light box, although it is advisable at first to consult a therapist and do a treatment in their practice room. The amount of time needed to sit in front of the light and the time of day will depend upon the individual person. Usually, 30 minutes of exposure daily at around 7am with 10,000 lux illumination is a good starting point for those who are drowsy in the mornings, or for people suffering from SAD. However, some people have found that this amount can cause irritability and choose to shorten the sessions, do the treatment later in the day, or sit further from the light. .

Natural daylight also stimulates the body to produce Vitamin D, essential for the absorption of certain minerals, including calcium. The UV rays in daylight have an antiviral, antifungal and antibacterial effect, thought to help clear skin infections such as acne and psoriasis. However, over exposure to UV light must be weighed against the risk of skin cancer.

Several mild adverse effects have been reported with Light Therapy such as eye irritation and headaches, but these tend to go quickly or can be controlled by reducing the exposure to light. Because each person to be treated is different from the next, it can take a couple of sessions to determine how much exposure is suitable. People with progressive diseases of the retina and people who are taking medicines associated with photosensitivity, should avoid Light Therapy. A qualified medical practitioner should be consulted.

Conditions suitable for treatment :

There have been several studies to show that SAD exists and can be treated by Light Therapy, while there is also good evidence to support the use of Light Therapy for the treatment of psoriasis.

Other uses for Light Therapy are to treat skin conditions, depression, insomnia and disturbed sleep patterns, such as jet lag.