Jul
30
2016

LED Streetlights Can Be Harmful

The American Medical Association (AMA) has just released a new policy recommendation and statement that LED streetlights can be harmful. After meticulous reviews of the research on the effect of white LED streetlights and their effect on health the AMA decided that it needed to publish its recommendations so that city fathers have some guidelines for illuminating their cities.

Cost and energy savings from white streetlights

Many cities in the US have already switched from the yellowish traditional streetlights to the high-intensity LED lighting. The cities did this unilaterally without consulting health professionals or the public. The cities wanted to save money by using white LED lights. But as we will discover below there are serious health consequences to this.

Historic lighting solutions

We did not always have streetlights. Physicists use Kelvin units (K) to measure the intensity of light. The term“color temperature” (CT) is in us to describe color composition. Before Benjamin Franklin and Thomas Edison invented electricity we burnt candles and wood at night. This produced a light of 1800 K, which was yellow and red with hardly any blue. Next came incandescent light bulbs. They have a color temperature of 2400 K, which contains less blue and more yellow and red. The new light source is the LED light, which contains a lot more blue color and appears to us as white light. The color temperature is around 4000 K to 5000 K.

LED streetlights can be harmful to your health

Who would have thought that switching streetlights could have anything to do with your health? The newest LED street lights are emitting large amounts of blue light. Our eyes perceive this as white light, but it also creates nighttime glare, much more so than conventional lighting. Eye discomfort from blue-rich LED lighting can interfere with visual acuity and cause road hazards. The blue-rich LED streetlights happen to operate at the wavelength that suppresses melatonin during the night. Researchers believe that the white LED lamps cause interference with the important circadian sleep rhythm. This effect is much stronger with the white LED lights in comparison to the conventional streetlights. The interference with the sleep rhythm means that there is less sleep time. The sleep subjects reported that their sleep quality was unsatisfactory. There is daytime sleepiness and impaired daytime functioning. White light LED lights can even cause obesity.

Effect of white LED light on animals

Animals can also react to white LED light. The bright outdoor LED lights disturb many species that need a dark environment. Poorly designed LED lighting disorients some birds. Researchers detected that insects, turtles and certain fish species also experience disturbance in their habitat by white LED lights. US national parks have adopted lighting designs that reduce the effects of light pollution on wildlife. So far nobody has shown any concern, what light pollution does to humans!

AMA guidelines to reduce impact of white LED lights

The AMA has come out with new guidelines to help reduce the impact of white LED light. Instead of high-intensity white streetlights the AMA recommends to communities to use the lowest emission of blue light possible to reduce glare. The AMA has recommended a color temperature of no more than 3000 K. This type of light has more of a mix of blue, green, yellow and red in it and very little white. In contrast the CT of bright LED streetlights have 4000 K to 5000 K. This contains a lot of blue light, which appears as white to the eye. Seattle and New York belong to the cities that recently had their streetlights retrofitted to the white LED streetlights.

American Medical Association (AMA) recommendation

According to the AMA guidelines these lights should now be refitted again. The AMA also recommends that the lights should be shielded to minimize glare and the detrimental effect on humans and the environment. There should also be a possibility of dimming the lights in off-peak periods.

Evidence from medical literature that LED streetlights can be harmful

Here I am reviewing what has been found in the medical literature about white LED lighting that is now preferably used in street lighting.

Cataracts caused by high color temperature

A Chinese lab tested epithelial cell lines derived from human lenses under a variety of light sources. The lab had previously established that oxidative stress on epithelial cells from human lenses was the most important factor for developing cataracts in humans. Human epithelial cells were cultured in the presence of different LED light frequencies. A high color temperature of 7378 K caused damage to the epithelium while controls of lower color temperatures of 2954 K and 5624 K LED lights did not. The authors concluded that white LED light with a high color temperature could cause significant photobiological damage to human lens epithelial cells. This in turn can cause cataracts and legal blindness.

Human retinal cell cultures damaged by white LED light

Another research group studied human epithelial pigment retinal cells in tissue culture. They exposed the tissue cultures to various light frequencies, namely white, blue, green or red LED light. Reactive oxygen and DNA damage were assessed. The white light showed the highest amount of damage to the human retinal cell in culture.

Intermittent exposure to white LED light in long-term care residents

In a trial on senior long-term care home residents researchers found that intermittent exposure to bright light (versus red light) showed positive cognitive effects on the seniors. It is not clear why with respect to cognitive function there is a positive finding using white LED lights, while the other tests mentioned above showed negative effects on the lens and the retina of the eyes.

Blue light filters for night shift workers

In another investigation blue light filters were employed in night shift workers and the investigators detected beneficial health effects. In animal experiments the same results were found.

Normally in shift workers cancer, heart disease, metabolic disturbances, depression, anxiety disorders and reproductive problems are found.

 

LED Streetlights Can Be Harmful

LED Streetlights Can Be Harmful

Conclusion

Despite the evidence in the medical literature showing that yellow lights are better than the newer white LED lights, cities have been converting the yellow streetlights to white LED streetlights. It makes economic sense, but harms people. The American Medical Association is attempting to convince authorities to use common sense. The AMA wrote guidelines and hopes that city fathers will reconsider their decisions. If you are concerned, voice your opinion by talking to your political representative.

Oct
26
2013

Being SAD in Fall (Seasonal Affective Disorders)

Any general practitioner knows that fall and winter are the time when patients come in with a variety of complaints like a lack of energy, problems sleeping, inability to cope with stress, but often there may be non-specific pains like muscle spasm in the back, the shoulders, or indigestion. These symptoms can all be part of seasonal affective disorders (SAD) like depression, the winter blues, often coupled with anxiety.

Emotional health does not fit easily into our health care model. The receptionist will warn the doctor that this is going to be a “difficult” patient. If the doctor has only time for a 5 or 10-minute visit, where only one or two problems can be dealt with, then this does not fit when a patient with SAD has a problem concentrating, falling asleep, and presents with a long list of other complaints. Even 20 minutes or 30 minutes may not be enough to deal with this patient adequately. It is easier to send the patient for tests and to prescribe an antidepressant and a sleeping pill and reschedule for a follow-up appointment. But this likely will result in normal blood tests and investigations, added health care costs, but no solution to the patient’s problem when he  or she simply states “doctor, I feel so sick”.

I thought it would be interesting to review how our emotions can get out of balance and review an integrative approach to SAD.

Definition of SAD

Seasonal depression (also called seasonal affective disorder) occurs during fall (autumn) and winter, but this alternates with no depressive episodes during spring and summer. A person defined to suffer from SAD would have suffered from two major depressive episodes during the past 2 years with no depressive episodes in the intervening seasons of spring and summer (Ref.1). Alternative names for SAD are winter depression and wintertime blues. Typically SAD lasts about 5 months.

Brain hormone disbalance

Around 2002 it was detected that in mice there was a second light sensitive pathway from ganglion cells in the retina that were responsible for circadian hormone rhythms. This was later confirmed to be true also in humans, where photosensitive retinal ganglion cells buried deep in the retina and containing the pigment melanopsin absorb blue light in the visible light spectrum. The electrical signals are sent along the retinohypothalamic tract, so that light from the retina regulates the hormone circadian rhythm (daily hormone fluctuations including the sleep/wake cycle) in the hypothalamus. The hypothalamus is one of the major hormone centers in the center of the brain. As this publication shows there are minor genetic sequence changes for the retinal photopigment, melanopsin in patients with SAD. This affects about 1 to 2% of the American population. Many more have probably partial defects in the function of this pigment.

Being SAD in Fall (Seasonal Affective Disorders)

Being SAD in Fall (Seasonal Affective Disorders)

Many hormones in our brain experience a circadian rhythm.

When the sun goes down, melatonin is produced making us sleepy. In the morning serotonin production goes up and stays up all day, which normally prevents depression. There are other hormones that cycle during the course of the day. Cortisol is highest in the morning and low in the evening and at night. Growth hormone and prolactin are highest during sleep.

There is a lack of serotonin in the brains of patients with SAD and depression.

Symptoms of SAD

A person affected by SAD or any other patient with ordinary depression will present with symptoms of lack of energy, with tearfulness, negative thought patterns, sleep disturbances, lack of appetite and weight loss and possible suicidal thoughts. On the other hand symptoms may be more atypical presenting with irritability and overindulging in food with weight gain. Some patients somaticize as already mentioned in the beginning of this review experiencing a multitude of functional symptoms without any demonstrable underlying disease. It is estimated that up to 30 to 40% of patients attending a general practitioner’s office have some form of depression and in the fall and winter season a large percentage of them are due to SAD.

Treatment approaches to SAD

There are several natural approaches to SAD. However, before deciding to go this route, a psychiatrist should assess the patient to determine the risk for suicide. When a patient is not suicidal, light therapy can be utilized.

1. Light therapy: According to Ref. 2 a light box from Sun Box or Northern Light Technologies should be used for 30 minutes every morning during the fall and winter months. The box should emit at least 10,000 lux. Improvement can occur within 2 to 4 days of starting light therapy, but often takes up to 4 weeks to reach its full benefit (Ref.2).

2. Exercise reduces the amount of depression. The more exercise is done the less depression remains. A regular gym workout, dancing, walking, aerobics and involvement in sports are all useful.

3. Folate and vitamin B12: Up to 1/3 of depressed people have folate deficiency. Supplementation with 400 mcg to 1 mg of folic acid is recommended. Vitamin B12 should also be taken to not mask a B12 deficiency (Ref.3). Folate and vitamin B12 are methyl donors for several brain neuropeptides.

4. Vitamin D3 supplementation: A large Dutch study showed that a high percentage of depressed patients above the age of 65 were deficient for vitamin D3. Supplementation with vitamin D3 is recommended. (Ref.3). Take 3000 to 4000 IU per day, particularly during the winter time.

5. St. John’s Wort (Hypericum perforatum) has been found useful for minor to moderate depression. It is superior in terms of having fewer side effects than standard antidepressant therapy (Ref.3).

6. Standard antidepressants (bupropion, fluoxetine, sertraline and paroxetine) are the treatment of choice by psychiatrists and treating physicians when a faster onset of the antidepressant effect is needed (Ref.3).

7. Electro acupuncture has been shown in many studies to be effective in ameliorating the symptoms of depression and seems to work through the release of neurotransmitters in the brain (Ref.4).

8. A balanced nutrition (Mediterranean type diet) including multiple vitamins and supplements (particularly the vitamin B group and omega-3 fatty acids) also stabilize a person’s mood (Ref.3). Pay particular attention to hidden sugar intake, as sugar consumption is responsible for a lot of depression found in the general population.

9. Restore sleep deprivation by adding melatonin 3 to 6 mg at bedtime. This helps also to restore the circadian hormone rhythm.

Conclusion

Seasonal affective disorder is triggered by a lack of light exposure in a sensitive subpopulation. An integrative approach as described can reduce the amount of antidepressants that would have been used in the past in treating this condition. This will reduce the amount of side effects. The use of a light box can reduce the symptoms of this type of depression within a few days. But the addition of electro acupuncture and St. John’s Wort may be all that is required for treatment of many SAD cases. Regular exercise and a balanced nutrition (with no sugar) and including vitamin supplements complete this treatment. If the depression gets worse, seek the advice of a psychiatrist and make sure your doctor has ordered thyroid tests and hormone tests to rule out other causes where depression is merely a secondary symptom.

More information on depression: http://nethealthbook.com/mental-illness-mental-disorders/mood-disorders/depression/

References

  1. Ferri: Ferri’s Clinical Advisor 2014, 1st ed. © 2013 Mosby.
  2. Cleveland Clinic: Current Clinical Medicine, 2nd ed. © 2010 Saunders.
  3. Rakel: Integrative Medicine, 3rd ed. © 2012 Saunders.
  4. George A. Ulett, M.D., Ph.D. and SongPing Han, B.M., Ph.D.: “The Biology of Acupuncture”, copyright 2002, Warren H. Green Inc., Saint Louis, Missouri, 63132 USA

Last edited Nov. 7, 2014