Light Therapy for Anti-Ageing

Scientists, doctors and beauty experts have long been searching for a cure for ageing, particularly with regard to the skin. New topical treatments and technologies frequently erupt into the aesthetic and cosmetic commercial scene. In recent years, one potential anti-ageing treatment has garnered more attention than others, and that is light therapy. 

Discussion about light therapy for anti-ageing has centred around what beneficial effect, if any, it has on the skin, whether the ‘at-home’ devices being marketed live up to their hype, and what the potential side effects or long-term complications are.

Here we will discuss the latest evidence around light therapy for anti-ageing, what effect it has on your skin, the benefits you can expect to see and who shouldn’t use it.

The basics of skin and ageing

The skin is the largest multifunctional organ in the body. It is capable of synthesising vitamin D, carries out thermoregulation (keeping the body temperature optimal) and plays an important role in certain inflammatory and immunological responses. However, its primary function is to provide a protective barrier against chemical, physical and biological assaults.¹

Ageing is an unstoppable, degenerative process that occurs in all parts of the body over time. Skin ageing occurs via two processes, intrinsic ageing and extrinsic ageing.¹ 

Intrinsic ageing is a natural process that is programmed to happen over time, whereas extrinsic ageing is skin ageing that occurs at an increased rate due to modifiable risks. It is often termed ‘photo-ageing’ and the main culprit is exposure to harmful UV light from the sun or tanning beds, however smoking and malnutrition also play significant roles.¹

The skin is made up of three distinct layers, the outer layer is the epidermis and its main function is to provide a protective barrier.² The middle layer (called the dermis) is responsible for the elasticity and strength of the skin and is rich in collagen. The deepest layer is called the hypodermis.² The hypodermis connects the skin to your muscle and bone and contains fat cells which help to insulate your body as well as acting as a shock absorber, and together with sweat glands help regulate body temperature.²

Ageing of the skin results in deep wrinkles, dryness, reduced skin elasticity and pigment formation.³ The demand for ‘anti-ageing’ skin solutions has continued to grow rapidly over recent decades. The cosmetic, aesthetic and medical industries are continuously searching for new, clinically effective and safe methods to halt, or at least slow, the effects of ageing on the skin.

What is light therapy?

Light therapy, also referred to as ‘photobiomodulation’ or ‘low-level light therapy’ is a painless, non-invasive therapy where different types of light are shone onto the skin inducing several pathophysiological reactions within the different layers of the skin.⁴ Light therapy is pain-free and does not cause any damage or trauma to the skin that other anti-ageing treatments, such as laser resurfacing, can cause.⁴

The use of light therapy to treat dermatological conditions was explored in the 1990s by NASA. NASA used light therapy on astronauts as a means of promoting wound healing whilst in space by inducing cell and tissue growth. In recent years light therapy has been licensed to be used by dermatologists (doctors who specialise in the skin) to treat several skin conditions such as acne, hair loss, psoriasis, actinic keratosis and non-malignant skin cancers.⁵

Light therapy is still very much an emerging treatment and there is still a lot of ongoing debate around its effectiveness, uses, contraindications and risks.

Different types of light

A number of different colours and types of light exist. Light is classified according to its ‘wavelength’ and each wavelength of light has a unique impact on the body. 

The types of light that are used in light therapy include blue light, yellow light, red light and near-infrared light. These types of light have different wavelengths that correspond to different visible colours and can be used to treat a variety of diseases. Each wavelength of light has a different effect on the skin.

The types of light used in light therapy for anti-ageing are:

• Blue light (420-440nm) – this has the shortest wavelength and has impacts on the most superficial layer of the skin, the epidermis 
• Red light (630-680nm) – this travels into the deeper dermal layer of the skin 
• Near-infrared light (750-1200nm) – this wavelength of light penetrates the deepest within the dermal layer of the skin^7,8

The most commonly ‘heard of’ type of light is ultraviolet light (UV light). 

UV radiation is the light produced by the sun and can be categorised into UV-A, UV-B and UV-C. This UV radiation should not be confused with the type of light used in light therapy.

UV-C is the most harmful form of radiation however it is almost completely filtered out by the ozone layer in the earth's atmosphere. 

UV-A is the most harmful form of UV radiation, that is encountered by humans daily because it is responsible for 95% of UV radiation that reaches the surface of the earth. It can penetrate through glass, down to the middle layer of skin (the dermis) and is responsible for causing sunburn and cell damage. It is a main contributing factor for many skin disorders including malignant skin cancers as well as accelerated, or premature, skin ageing. 

UV-B rays penetrate into and affect the skin’s top layer (the epidermis), causing skin cancers and most sunburns.⁶

How does light therapy work?

The wavelength of each light affects how deeply it penetrates and thus where it works in the skin. In general, light therapy works by generating reactions within skin cells, modifying skin cell activity and stimulating several different chain reactions. This can lead to regeneration of tissue through enhanced production of collagen, a reduction in cellular inflammation and prevention of tissue damage.^7,12

Blue light

Blue light has the smallest wavelength, between 420 and 440nm. This means that it penetrates only the most superficial layer of the skin, the epidermis. Studies have shown that blue light can help to improve skin condition by killing the bacteria that live on the skin that are responsible for causing acne.⁷

Red light 

Red light has a wavelength of between 630-680nm and penetrates into the middle layer of the skin called the dermis. Scientists believe that the light creates a series of chemical reactions within the dermis of the skin that ultimately results in an increase in the production of collagen types I and III, an increase in the production of elastin, a reduction in cellular inflammation, and the production of fibroblasts which lead to improved skin healing.^4,7,8,9

Near-infrared light

Near-infrared works in a similar way to red light but penetrates deeper into the dermis, enabling it to reach more cells and have a much larger effect than red light.⁹

The anti-ageing effect of light therapy

Ageing of the skin is characterised by the development of fine lines and wrinkles, skin dryness, pigmentation and reduced elasticity.³ 

As described above, the wavelengths of light used in light therapy work on different layers of the skin and induce several reactions. The resulting increase in collagen and elastin are thought to be responsible for the reported improvement in fine lines and wrinkles that many studies have found, as well as an increase in elasticity of the facial skin.⁷ 

Light therapy also reportedly reduces inflammation within the dermal layer of the skin and kills acne-causing bacteria in the epidermis. Combined these positive effects reduce pigmentation and lesions on the skin and combat aging.⁷

Scientific evidence 

The interest in light therapy as a means of fighting the effects of ageing has rapidly grown in recent years, not just within the cosmetic industry but also among dermatologists. A number of light-emitting diode procedures and devices have been approved for use for a variety of skin disorders including for skin rejuvenation.⁷ 

Extensive studies have been performed using cellular, animal and human clinical trials to determine the effects of light therapy on the skin. These have found that different wavelengths of light induce various reactions within the skin resulting in an increase in collagen and elastin as well as other effects such as the destruction of acne-causing skin bacteria and a reduction in cellular inflammation. Whilst the mechanisms of action by which these effects occur are now well understood, the exact benefits that they result in are less clear. 

Some studies in humans have shown that using light therapy results in an improvement in the texture and colour of skin.^3,4 Other studies also found an objective improvement in fine lines and wrinkles due to an increase in collagen and elastin production.^3,4,7,8

However, some studies have found a limited anti-ageing effect comparable only to those who are using topical anti-ageing treatments. A significant limitation of the clinical trials that have been performed so far is that all of these studies involve only a small number of participants. Other limitations such as the absence of ‘blinding’ and ‘participant bias’ are also a concern. On the whole, the studies that have been released so far are a positive first step and generally show that the interest in light therapy on reducing skin ageing is warranted, however, they are by no means conclusive.

Most experts agree that large-scale randomised control studies are needed to give a definitive answer on the exact impact that light therapy has on anti-ageing.^13,14 Further studies are also required to guide the discovery of the best wavelengths to use and the optimal frequency and duration of treatment.

However, these initial studies have been useful in showing that there is a significant likelihood that light therapy can play a role in anti-ageing. Perhaps, more importantly, they have found that the risk of side effects of light therapy is very low and there is no evidence to suggest that there may be concerning long-term consequences.^4,10,11

Professional clinic setting versus ‘at-home’ devices 

The use of light therapy for anti-ageing skin treatment has previously been restricted to dermatological and aesthetic clinics. Devices found in professional settings tend to use stronger wavelengths of light than is possible to generate in an ‘at-home’ device. This likely leads to more noticeable and longer-lasting results. However, regular therapy for several weeks is required to see any positive changes and this can be difficult to facilitate when treatment is only available at a clinic. 

‘At-home’ light therapy devices are becoming more and more popular, with a number of different brands popping up over the last couple of years. As technologies improve it is becoming increasingly possible and affordable to create an at-home device that is of the same efficacy as those available in the professional setting. This means it may become quick, cheap and easy to regularly use a light therapy device and thus allow you to fight the effects of ageing on your skin.

How to use an at-home device

Every device is different so it is important that you read the manual which accompanies your device and follow the instructions carefully.

Each device will have a recommended frequency and duration. These will likely start at lower limits and gradually increase as your skin becomes used to the treatment. If you have any concerns before starting the regime then make sure you speak to your healthcare provider first. 

Combining light therapy with other skincare routines

Many light therapy treatments are combined with topical facial treatments to help boost the anti-ageing effect. For ‘at-home’ devices where the light is in contact with the skin an oil or ointment is often recommended to ensure even and smooth contact with the skin as the light-emitting diode is moved across it.

Potential risks, precautions and contraindications

Who shouldn’t use light therapy?

Whilst light therapy is safe for all skin types and colours and does not use harmful UV light, there are still some people who shouldn’t use it:

• Those taking certain medications that increase your sensitivity to sunlight e.g. isotretinoin 
• Anyone with a history of skin cancer
• Anyone with a history of photosensitivity reactions, also referred to as polymorphic light eruption or ‘sun allergy’, shouldn't use light therapy

If you have any questions or concerns about whether using light therapy is for you then it is best to first discuss these with a dermatologist.

Precautions 

Whilst light therapy doesn’t use the type of light that is harmful to your skin, it can be dangerous to the eyes. It is important to carefully follow the instructions of your particular device concerning eye care to minimise any risk of damage.

Potential side effects 

Whilst most studies have found that the risk of adverse reactions from light therapy is low there are still some signs you should watch out for:

• Skin rashes 
• Redness
• Pain 

If you’re experiencing any unexpected side effects, stop use immediately and contact your healthcare provider.

Common challenges and misconceptions

Many people get confused with the term ‘light therapy’ and believe this means that it uses harmful UV light same as that found in sun beds. This is not the case and the risk of harmful side effects from the use of light therapy is very low.

The current lack of definitive evidence has led people to use anecdotes as evidence that light therapy has a strong positive effect against skin ageing. However, while some people may subjectively report a strong improvement in wrinkles, fine lines, skin texture and moisture the fact of the matter is that there is no rigorous scientific evidence to back this up. Therefore, there is no guarantee that using light therapy will result in any measurable improvement in your skin.

Summary

Light therapy has been used by dermatologists as a method of treating a variety of skin disorders for many years. However, in recent years, interest in its ability to potentially delay or reverse the effects of ageing on the skin has rapidly increased. Studies have shown that using low-level light in the blue, red and, near-infrared spectrum on our skin induces cellular and biochemical changes to the epidermal and dermal layers resulting in an increase in the production of collagen, elastin and a reduction in inflammation.

However, the jury is still out on what exact observable changes in our skin this results in. Small-scale human trials have found that there is a significant likelihood that light therapy can help reduce wrinkles and fine lines as well as improve the texture and colour of the skin thus combating the most undesirable aspects of skin ageing. However, more rigorous scientific evidence and larger studies are required to support this.