Just two minutes' exposure to blue light from lamps used for tooth whitening was enough to kill bacteria in saliva associated with bad breath, according to one study.
Just two minutes' exposure to blue light from lamps used for tooth whitening was enough to kill bacteria in saliva associated with bad breath, according to one study.

Turn on the light for better health

By ROGER DOBSON Time of article published Aug 3, 2012

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London - Scientists are harnessing the power of light to tackle dozens of diseases.

Although we all know how beneficial a blast of warm sunshine can be for the constitution, scientists are now using light to treat a host of conditions including stroke, bad breath, hay fever and even cancer.

Dermatologists were among the first specialists to use light therapy, also called phototherapy, to ease skin conditions, including psoriasis. Psychiatrists then discovered it could be used with some success to treat seasonal depression, a form of mental illness that strikes during the winter months.

Here, we reveal the conditions that could be helped with rays of light...


Blue light is now being used as a treatment for back pain.

Blue light is a component of so-called visible light, and is seen when light is split into its constituent colours - such as when you see a rainbow.

Although harmless to tissue, blue light is strong enough to trigger biological effects in the body, and it’s being used increasingly for a range of medical treatments.

Doctors at the University Hospital of Heidelberg have developed a patch that emits blue light to treat pain.

This is based on early studies that suggest the light stimulates the body’s production of nitric oxide. This relaxes muscle fibres (reducing painful muscle spasms) and widens blood vessels (increasing blood flow to the area, which can increase the supply of pain-relieving molecules).

In a new trial, the patch will be used five times over 14 days for 30 minutes each time. Meanwhile, a US study is looking at the use of light in treating the pain of knee osteoarthritis.

Commenting on light therapy, Jane Tadman, of charity Arthritis Research UK, says: “We know that light therapy increases nitric oxide, which has been shown to reduce both chronic and acute pain.

“A recent study showed this therapy was effective in reducing shoulder pain without any side-effects. We think light therapy may be another tool for people with arthritis to cope with the pain of the condition.”


Blue light may also help combat bad breath. Just two minutes’ exposure to blue light from lamps used for tooth whitening was enough to kill bacteria in saliva associated with bad breath, according to one study.

Researchers at the Hebrew University and Hadassah School of Dental Medicine in Jerusalem used the light on 50 samples of saliva, and results show blue light caused a significant drop in odour.

They found that the balance of bacteria in the samples was changed by the light, making the most smelly bacteria less dominant.

Scientists at Harvard University have found that blue light can also be used to combat bacteria associated with destructive gum disease.

The researchers say the light might be useful in preventing, controlling or treating periodontitis, an oral infection that can lead to loss of bone and teeth. Some of the bacteria were eradicated within seconds, said Dr Nikos Soukos, who led the research. It’s thought the light kills the bacteria by disrupting the protective coating around each bacterium.


Infra-red light - the type used in TV remote controls - has been shown to speed recovery after stroke.

This type of light passes easily through the scalp and skull, and researchers at Boston and Harvard universities say it may stimulate the growth of brain cells.

One study showed light therapy significantly improved outcome in stroke patients when used over the entire surface of the head around 18 hours post-stroke.

Another study found that 70 percent of patients who had light therapy, which is delivered via a type of hairnet, had a better outcome than those who did not.

Just how light works is not clear, but the researchers say it could prevent the death of further brain cells by triggering the release of protective antioxidants and key proteins.

Infra-red light therapy shone through the skull has potential in the treatment of a number of neurodegenerative diseases.

Animal and laboratory studies have shown significant benefits in Alzheimer’s disease, and three clinical trials are currently under way.


Ultraviolet light - the type of light that burns the skin and is also used in sunbeds - can help treat skin conditions. Although the rays cause damage in high doses, in small, moderated amounts the light is thought to reduce inflammation, helping dampen conditions such as eczema, acne, psoraisis and vitiligo (uneven pigment in the skin).

A small study at University Hospital Gasthuisberg, in Belgium, found that ultraviolet light exposure reduced skin itching by more than 60 percent.


Shining a special light into the nose can ease the symptoms of allergic rhinitis - inflammation of the inside of the nose caused by an allergen, such as pollen, dust or mould.

Scientists have developed a type of light that delivers a painless high-intensity beam of light up into the nose.

It is thought to reduce the body’s immune response to the allergen, in turn reducing inflammation.

A study that was published in the Journal Of Allergy And Clinical Immunology, and based on 49 allergy patients not responding to the usual medication, showed significant reduction in sneezing and nasal itching after treatment with the hand-held light device.


Chronic wounds, including diabetic foot ulcers and pressure ulcers, have been successfully treated with light therapy.

In one study at Huddinge University Hospital, Stockholm, a combination of red light and infra-red light increased the pressure ulcer healing rate by 54 percent, and 90 percent of the pressure ulcer area healed within five weeks. This contrasted with nine weeks in a comparison group.

It’s thought that light increases blood flow so that greater amounts of oxygen reach the wound area, resulting in faster healing.


Doctors are using light to combat the disease in a type of treatment called photo- dynamic therapy.

This is most commonly used to treat skin cancer, and uses a special drug which makes cancer cells sensitive to light.

The patient is given a drug that is absorbed by cancerous tissue only. Doctors then expose the patient to blue light. This triggers the drug to release a type of oxygen that kills cancer cells.

Doctors believe the light-triggered drug also acts in other ways to shrink or destroy tumours.

It may, for example, damage blood vessels in the tumour, and stop it getting the nutrients it needs.

Some believe it may also trigger the immune system to attack the cancer.

For the treatment of internal cancers, including bile duct and gall bladder, oesophagus, head and neck, and lung, light can be delivered though a fibre optic system.


Light could be a new, non-invasive treatment for epilepsy. It is being investigated as a therapy for people whose seizures are poorly controlled with anti-epileptic drugs.

In a trial at University College London, patients will be exposed to a light box - which emits bright white light - for 30 minutes a day for three months.

It is based on a previous study that suggested people suffer fewer seizures on bright, sunny days than on dull, overcast days. Some studies also suggest epilepsy is more prevalent in northern than southern Europe.

One theory is that light increases levels of vitamin D and melatonin levels, which affect the production of brain chemicals that dampen seizures.


A device that bathes the inside of the stomach in blue light could be a new treatment for ulcers. The light kills the bacteria responsible for ulcers and some type of gastric cancers.

Research shows that shining the light into the stomach for less than an hour is enough to kill the bacteria without damaging healthy tissue.

The new device, currently on trial, is designed to tackle Helicobacter pylori bacteria, which infect more than a quarter of people at some stage.

Research at Northwestern Hospital in the US and other centres showed a 91 percent reduction in the number of bacteria after treatment. - Daily Mail

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