Introduction

Have you heard of alternative medical treatments that use the power of light to treat various diseases? 

Light therapy involves using light at specific wavelengths to stimulate certain biochemical changes in our body. It works on the principle that light at different wavelengths has a unique impact on our cells and tissues. Light therapy has found its way into treating many conditions like Seasonal Affective Disorder (SAD), sleep disorders, neonatal jaundice and many skin conditions. 

In this article let us dive into the science behind this fascinating treatment and learn about its applications and benefits.

A little history behind light therapy

In 1903 Niels Ryberg was awarded the Nobel Prize for his incredible work in demonstrating how chemical rays from sunlight can kill bacteria. He also showed how these rays can stimulate the tissues and can be used to treat various diseases like lupus vulgaris.¹

Then in the 1960s with the invention of laser light, many scientists noticed how low doses of laser could be used to enhance hair growth and promote wound healing. This phenomenon was referred to as “Laser biostimulation”. 

Further, in 1991, a group of scientists (Whelan and his team) discovered how light-emitting diodes (LEDs) can be used in medicine. Their work laid the foundation for exploring the potential health benefits of LEDs. 

Since then the field of light therapy or laser therapy, also known as phototherapy, has gained widespread acceptance and has been used to treat many diseases.^1,2

Conditions treated with light therapy

Light therapy for musculoskeletal pain

Musculoskeletal pain affects many people. It reduces our productivity and is one of the common reasons for absence from work or school. 

Though conventional methods of treatment are helpful, they come with a lot of side effects and complications. Now with a better understanding of how light therapy works, light in the red to near-infrared range of the spectrum with wavelength between 660–905nm is commonly used to relieve musculoskeletal pain. 

Studies have shown that when this light is focused for up to a minute on the site of pain, a few times a week, it effectively reduces inflammation and relieves pain. Additionally, it promotes the healing of the tissue.

• Low-dose light therapy is now used to treat many orthopaedic conditions like sprains and strains, tendinitis, frozen shoulder, rheumatoid arthritis, osteoarthritis, and carpal tunnel syndrome.
• Painful dental conditions like hypersensitivity and third molar removal surgery can also be managed well with light therapy.
• Neural conditions like trigeminal neuralgia and diabetic neuropathy can also be treated with light therapy.³

Light therapy for skin conditions

Light therapy is now used to treat several skin conditions. Depending on the level of penetration different LED lights are used for different conditions. Two of the most popular types of light therapy used to treat skin conditions are:

Red light therapy: 

• Red light can penetrate deeper layers of skin and enhance the production of collagen. 
• This helps to heal the skin better. 
• It also reduces signs of inflammation. 
• Red light is often used to reduce or reverse the signs of photoaging.

Blue light therapy: 

• Blue Light affects the most superficial layer of the skin. 
• It can reduce the activity of sebaceous glands in the skin thereby preventing clogging of the pores and follicles.
• Blue light may also kill Cutibacterium acnes, the bacteria that are generally known to cause acne. 
• Sometimes red light is also used in combination to treat acne as it can reduce inflammation associated with acne.

A recent study has shown Intense Pulsed Light Therapy can be used in the treatment of acne-induced post-inflammatory erythema (PIE), a condition that is usually difficult to treat. In the same study, it was also observed that this form of light therapy reduced the oiliness of the skin, and improved the skin tone and texture.⁴

In skin conditions like vitiligo, Low-Level Laser Therapy (LLLT) can be used as it is seen to enhance pigmentation by increasing the growth of pigment-producing skin cells called melanocytes and decreasing the loss of skin colour by slowing down the immune response.⁵

Light therapy has also been useful in treating other skin conditions like psoriasis, stretch marks, rosacea, sun damage, wrinkles, and hair loss.³

Light therapy in the treatment of cancer

Light therapy with the use of a laser or an LED source is used in the treatment of some cancers. This modality of cancer management is called Photodynamic therapy. It involves first giving the patient a particular drug which gets activated when exposed to light at a specific wavelength. This activated drug then kills the cancer cells.^6,7

The advantage of light therapy in treating cancer is that it is less invasive. However, the downside is that it could damage the normal cells surrounding the cancer cells. It can also cause swelling, pain, and scarring.

Since the light cannot penetrate very deeply it is used to treat superficial tumours and may not be useful in the treatment of large tumours. 

A few cancers where phototherapy has been seen to be helpful are:

• Actinic keratosis
• Squamous cell carcinoma
• Basal cell carcinoma
• Cutaneous T-cell Lymphoma
• Esophageal cancer
• Small cell cancer of the lung^6,7

At-home devices like masks are also available now that you can use in the comfort of your home. All the safety instructions must be followed while using the device. It is best to consult a dermatologist to know if you can use at-home devices or require in-office treatment.³

Light therapy for Seasonal affective disorder (SAD)

Apart from beautiful, picturesque snowfall, winter also brings grey skies, less sunlight, and a low mood. Many people experience winter blues which is scientifically called Seasonal Affective Disorder (SAD).

This happens because less exposure to sunlight disrupts not just our biological clock (circadian rhythm) but also affects digestion, hormonal activity, and proper functioning of the brain. 

SAD is a mood disorder that has a seasonal pattern as it starts during autumn or winter and fades off during spring. Most people, along with depression, also experience a tendency to sleep more, increased appetite, weight gain, irritability and difficulty concentrating.⁸

One common approach to treat Seasonal Affective Disorder is light therapy. In light therapy for SAD, all you have to do is spend some time, typically 30 minutes to an hour every morning in front of a special lamp or light source known as a lightbox.

How does light therapy help to improve symptoms of SAD?

The light from the light box mimics sunlight.  This prompts the brain to reduce the production of sleep-inducing hormones i.e. melatonin and increase the production of serotonin, a hormone that regulates your mood.

Studies have shown that light therapy can also be used in the treatment of major depression and depression that occurs during or after pregnancy (perinatal depression).^9,10

While for many it is free of adverse effects some people may experience headaches, blurred vision, tiredness, and irritability. So it is advised to talk to your doctor before you start using a lightbox to avoid any unnecessary complications, especially if you have pre-existing medical conditions or are taking medications that may interact with light therapy.

Light therapy for insomnia

As light influences our sleep-wake cycle or our biological clock, many studies have found that light therapy may be a natural, simple, and low-cost approach to treating sleep disorders.

Although light therapy can have side effects like frequent headaches and eye strain, it is free of adverse effects and tolerance issues seen with the use of sleeping pills.¹¹

Light therapy for neonatal jaundice

Jaundice is a common medical condition in newborn infants. It occurs due to the increase in the level of a compound called bilirubin in the blood. Excess bilirubin can get deposited on fatty tissue turning the baby’s skin and the whites of the eyes yellow. While some babies with jaundice recover without any treatment, some may require light therapy popularly referred to as phototherapy.

Phototherapy involves using a special type of light to eliminate the excess levels of bilirubin from the blood.¹²

FAQs

What is light therapy?

Light therapy involves using specific wavelengths of light to bring about certain biochemical changes in the body, offering healing benefits.

How does light therapy work for skin conditions? 

Different LED lights, like red and blue, penetrate the skin at various levels, promoting collagen production, reducing inflammation, and addressing issues like acne and ageing.

Can light therapy treat cancer?

Yes, light therapy (photodynamic therapy) is used to treat certain cancers by activating drugs with specific wavelengths of light.

Is light therapy safe for insomnia? 

Light therapy is a natural and low-cost approach to treating insomnia, although it may cause side effects like headaches, irritation, and eye strain in some.

Summary

Light not only enables us to see objects and appreciate beautiful colours but it also has a great impact on our circadian rhythm, sleep-wake cycle, and our mood. This makes light therapy a wonderful cost-effective treatment option to fix sleep disorders and certain psychiatric conditions.

With the advancement of science and a better understanding of laser biostimulation, light therapy is now used to treat various skin conditions and some types of cancers.

One key takeaway here is that at-home devices for light therapy are generally considered safe and effective but consultation with healthcare professionals is crucial for safe and effective use. The ongoing research and advancements in this field promise an even brighter future for those seeking alternative and effective medical interventions.