Doctors have learned to use light to treat dementia

In authoritative medical publications, two curious scientific studies appeared at once, devoted to one of the most important social and medical problems of our time – dementia. In the first work, scientists practically proved the connection between exposure to polluted air and the development of dementia. It is sad. But the second work is encouraging: scientists have substantiated the high efficiency and safety of the treatment of dementia … with light.

Over 57 million people worldwide are living with dementia. Its cases are projected to increase to 153 million in 2050. Scientists all over the planet are looking for ways to treat this insidious disease, and at the same time the possibilities of its prevention, delay or prevention. A study published in the BMJ journal is devoted to potential prevention, the authors of which tried to assess the risks of exposure to air pollution on cognitive abilities.

Of course, the main risks of increasing the coverage of the world’s population with dementia are associated with aging. Yet up to 40% of the prevalence of dementia is estimated to be preventable by addressing modifiable risk factors. Air pollution is just one of them.

That long-term outdoor air pollution can lead to an increase in dementia has already been argued based on evidence supporting an association between air pollution exposure and cardiovascular disease, stroke and cognitive impairment. Exposure to particulate matter in ambient air has been found to lead to systemic inflammation, damage to the blood-brain barrier, and increased neuroinflammation that can lead to neuronal death. Other studies have shown that reduced air pollution concentrations are associated with reduced mortality. The number of studies evaluating the link between outdoor air pollution and dementia has increased over the past decade, but their validity is questionable. The authors of a new systematic review attempted to close this annoying gap by using the latest tools for accurate assessment.

They analyzed the scientific literature with studies on this topic and eventually included 51 studies in the meta-analysis. As a result, they were able to establish a significant relationship between the effect of fine particles on the risks of clinical dementia. The authors concluded that the excess concentration of fine particles in the atmospheric air may be a risk factor for dementia, as well as nitrogen dioxide and nitric oxide. However, studies are needed to evaluate critical periods of exposure, as well as the contribution of other pollutants.

…Another scientific work, published in the journal Brain and Behavior, talks about a method of therapy that has long been used in medicine, but, as it turned out, is also promising in relation to dementia. Dementia is known to be characterized by progressive and severe cognitive impairment, motor deficits, and behavioral problems. It not only affects the quality of life of individuals, but also imposes a huge social and economic burden on families, health systems and society. With population aging around the world, dementia has become an important public health problem and there is a desperate need for effective and affordable treatment. At the same time, drug treatment of dementia is not yet highly effective, often has medical contraindications and side effects. The eyes of scientists are increasingly directed towards non-pharmacological therapy: today it is considered as the most important part of the complex treatment of dementia. Scientists call phototherapy a promising method, the advantages of which are non-invasiveness, low cost and high safety.

The authors of a new meta-analysis evaluated 12 studies examining the effect of phototherapy interventions on cognitive function in older patients with dementia, as well as behavioral and psychological symptoms of dementia and sleep. And they came to encouraging conclusions: this is not a panacea, but the method works!

“Throw away the pills, turn on the light,” comments a well-known therapist, military doctor Alexei Vodovozov. – The authors of the work showed that phototherapy is a safe, effective and inexpensive method of treatment. Phototherapy, which uses bright full-spectrum light (usually over 600 lux) or light at specific wavelengths (such as blue-green), was much better for cognition, they found, although it did not affect sleep or depression. At the same time, light can compensate for the decrease in visual sensory information in patients with dementia and stimulate certain neurons in the suprachiasmatic nucleus of the hypothalamus to regulate the circadian rhythm – this is how the authors explained their finding.

The duration of phototherapy usually ranged from 6 to 120 minutes. Half of the studies (6 out of 12) received phototherapy at specific times of the day: three in the morning, one in the afternoon, one at dawn and dusk, and one in the morning and afternoon. Frequency ranged from twice a day to five times a week, with most studies (9 of 12) using phototherapy once a day. Adverse events in all studies were extremely rare: 4 of 426 patients had mild problems: two developed symptoms of mild eye irritation; one had a slight redness on the forehead, which disappeared after about half an hour. And one patient refused treatment after 3 days of intervention because the treatment reminded her of torture during World War II.

“The study suggests that phototherapy may be one of the most promising non-pharmacological interventions to improve the underlying symptoms of dementia,” the researchers conclude.

According to them, the ideal regimen is exposure to bright full-spectrum light, typically over 2500 lux, for at least 30 minutes during the daytime, lasting 4-8 weeks. As an option: installing a luminaire mounted in the ceiling to provide design lighting throughout the day. In recent years, helmets and goggles have also been used as phototherapy devices, which typically use a specific wavelength of light for about 15 minutes, portable devices that allow better control of light intensity and are ergonomic without interfering with patients’ normal activities.

It is possible that neurological centers will be interested in this study and adopt a cheap and effective method.