Blue Light Revisited


Blue light was the subject of a blog post here a few weeks ago. If you missed it you can access it here:

We are finding more and more information on blue light and it’s effects and I wanted to go over a few more studies looking at it.

First, a report discussing the effects of shorter wavelength (blue) light. In the first, blue was compared to green. Exposure to blue light induced a 2 fold greater circadian phase delay than green light. That means that both green light and blue light are resetting your circadian clock. The total amount of reset is dependant on intensity and duration. [1]

Another study found similar results, comparing blue, blue-green, green, red and amber with no light controls. Red and amber were found to not produce any significant difference over control. Blue and green again increased the onset of melatonin. [2]

Another study looked at subjects and their melatonin secretion, as well as perceived sleepiness. Subjects were given either blue, green, or no light after 1.5 hours of light, followed by 2 hours of dark. Light exposure then followed for two hours. 2 more hours of normal light exposure and then sleep. Here a jpeg to get all of that across.



Researchers found that melatonin was decreased in the blue and green groups, but to a lesser extent in the green group. Blue light also increased heart rate slightly but significantly, to the tune of 4 beats per minute. Core body temp also remained higher in the blue light group over the green and light groups. It appears that blue light increases sympathetic tone. That means that your fight or flight systems are a bit more active in the presence of blue light. [3]

Another study found that REM sleep was reduced by about 10 minutes per night when people were reading on E-readers than a regular book.[4] REM sleep seems to be linked with mood. [5]

Another study looking at 4th graders and 7th graders found that these students had less sleep when sleeping with electronic devices and/or TVs in their rooms than those who didn’t. [6] This of course makes sense. I’m more likely to stay up later and fight off sleep if I’m on the TV or reading than if I just go to bed. Maybe we as a society needs to be more wanting of sleep and not to be entertained.

Lack of sleep is bad for weight, depression, blood sugar, cardiovascular health and a whole host of other things.

Glasses made to filter out blue light seem to help, as noted in one study. [7] I made mention of these in the previous post.

In another study done with glasses to filter out blue light in adolescent males, researchers found that melatonin was increased if the blue filter lenses were used. [8] The authors in this study noted that no circadian rhythm was changed, but they hypothesized that one week, the length of the study, may not have been long enough.

These types of glasses may be useful, especially those that are working night or swing shifts. They can be purchased fairly inexpensively too. Plus you don’t typically have to lug them around everywhere. You can keep them at you desk or by your bed.

Naturally it’s better to just avoid computer and phone use before bed, but that can be very difficult, especially if the job demands it. Try some glasses out or other forms of entertainment at night, like sleep or reading a book.



1.Lockley, Steven W., George C. Brainard, and Charles A. Czeisler. “High sensitivity of the human circadian melatonin rhythm to resetting by short wavelength light.” J Clin Endocrinol Metab 88.9 (2003): 4502-4505.

2.Wright, Helen R., Leon C. Lack, and David J. Kennaway. “Differential effects of light wavelength in phase advancing the melatonin rhythm.” Journal of pineal research 36.2 (2004): 140-144.

3.Cajochen, Christian, et al. “High sensitivity of human melatonin, alertness, thermoregulation, and heart rate to short wavelength light.” The Journal of Clinical Endocrinology & Metabolism 90.3 (2005): 1311-1316.

4.Chang, Anne-Marie, et al. “Evening use of light-emitting eReaders negatively affects sleep, circadian timing, and next-morning alertness.” Proceedings of the National Academy of Sciences (2014): 201418490.

5.Cartwright, Rosalind, et al. “Role of REM sleep and dream affect in overnight mood regulation: a study of normal volunteers.” Psychiatry Research 81.1 (1998): 1-8.

6.Falbe, Jennifer, et al. “Sleep Duration, Restfulness, and Screens in the Sleep Environment.” Pediatrics (2015): peds-2014.

7.Wood, Brittany, et al. “Light level and duration of exposure determine the impact of self-luminous tablets on melatonin suppression.” Applied ergonomics 44.2 (2013): 237-240.

8.van der Lely, Stéphanie, et al. “Blue blocker glasses as a countermeasure for alerting effects of evening light-emitting diode screen exposure in male teenagers.” Journal of Adolescent Health 56.1 (2015): 113-119.


Does Magnesium Help Sleep?

In last week’s post we discussed some of the possible benefit of giving up electronic screens before bed to avoid blue light. Some people may even wear yellow/orange visors to filter out the blue light.

Today I want to talk about something I’ve mentioned before, and something that many people lack; magnesium.

Magnesium is a metal that is required in the body for over 300 different reactions. It is found in many different foods in various quantities and sold in you local drug stores, supermarkets and everywhere else. The substance has been used for numerous ailments, and rightly so, since it has a wide variety of uses in the body.

So does it help in sleep?

In your brain there is a neurotransmitter called GABA  which is responsible for some of the calming actions in the brain. If the brain had an “on” and “off” switch, GABA could be likened to the off. That is a very basic view of it and there is more involved to it, but for the purposes of this talk lets keep it simple. If you’re interested in some heavier reading, or if you want to read it to put you to sleep, you can go here:

In the evening, in the hypothalamus, GABA is used, as well as another transmitter called galanin, to calm the brain down. It does so by inhibiting the arousal areas of the brain. It’s kind of like when you had a friend spending the night at your house and you’d get a bit loud, then your dad came and banged on the door or wall telling you to pipe down. GABA kind of does the same thing.

Here’s the thing; GABA is potentiated by magnesium [1].

People who have chronically low levels of magnesium may have problems falling asleep and staying asleep. I can’t speak to the number of people who come into the pharmacy for things like zolpidem for sleep, but I’d love to see what their magnesium levels are and if something like a supplemental magnesium would help. I do know we over prescribe sleep agents.

From a personal note, I have had better sleep with magnesium and know people to whom I’ve recommended it get better sleep as well. I know this is anecdotal, but it is strong enough evidence for me to recommend it.

In a small trial in Italy, researchers looked at supplemental magnesium with zinc and melatonin in patients living in long-term care facilities. They found that this combo helped the patients get to sleep faster and it was more restful. [2] The downside is that in this study, because they used 3 supplements together, we can’t extrapolate the benefit just to the magnesium, especially as we know that melatonin can also help people with sleep.

Magnesium can also address issues of restless leg [3], muscle cramping and twitching, and cold hands.

As a side note, here’s a list of drugs that deplete magnesium in the body:

-Birth Control Pills

-sucralfate (Carafate)



-corticosteroids (ie prednisone, dexamethasone, fluticasone)

-divalproex (Depakote)

-phenytoin (Dilantin)

-triamterene/hydrochlorothiazide (Dyazide)


-hydrochlorothiazide (HCTZ)

-levetiracetam (Keppra)


-furosemide, torsemide, bumetanide

-gabapentin (Neurontin)



-senna (Ex-Lax)

I’ve said this before but it bears being repeated: Don’t take magnesium oxide! Magnesium oxide just doesn’t get absorbed well. If you want to use it to induce a visit to your nearest commode, then by all means, but if you’re actually looking to get magnesium into your blood there are better options.

There are lots of forms of magnesium. Be sure to get a good one.

There are lots of forms of magnesium. Be sure to get a good one.

Magnesium comes in various forms. Here are a few and some general uses:

1. Mag Oxide: As stated above this is good for getting a great laxative effect. This was the form used in the Italian study. It would have been interesting to see if another form had been used if it would have been even more effective.

2.Mag Glycinate: This one is well absorbed because of glycinate transporters in the gut. Both magnesium and glycinate have calming effects and may make this a good candidate for muscle hypertonicity and chronic pain. It has a small laxative effect compared to others.

3.Mag Malate: This one could be used for fibromyalgia as malate is a substrate for energy production. It is also well absorbed.

4. Mag Citrate: Well absorbed and a good all around option. Can still produce some loose stool though. This is the form I take.

5.Mag Orotate: This may be good for heart health as orotates get into the cell membranes easier and may benefit in cellular repair and energy production. [4,5] This may be good for people with cardiovascular disease

6. Mag Sulfate: This one is usually injected intravenously. It is also found in Epsom Salt baths.

These are just a few and there are more but if you stick to the above listed, minus the oxide, you’ll probably be just fine. 200-400 mg/day is likely what most people would need. You’ll have to titrate the dose depending on if you have really loose stool or not. Try some a couple of times a day without food.

If anybody has had any experience with magnesium and sleep please let me know about it. I’d love to hear what has worked for you.



1.  Uusi-Oukari M, Heikkila J, Lovinger DM, Luddens H, Korpi ER. Magnesium potentiation of the function of native and recombinant GABA(A) receptors. Moykkynen T, . Neuroreport. 2001 Jul 20;12(10):2175-9

2.Rondanelli, Mariangela, et al. “The Effect of Melatonin, Magnesium, and Zinc on Primary Insomnia in Long‐Term Care Facility Residents in Italy: A Double‐Blind, Placebo‐Controlled Clinical Trial.” Journal of the American Geriatrics Society 59.1 (2011): 82-90.

3.Hornyak, Magdolna, et al. “Magnesium therapy for periodic leg movements-related insomnia and restless legs syndrome: an open pilot study.” Sleep 21.5 (1998): 501-505.

4.Stepura OB, Tomaeva FE, Zvereva TV. Orotic acid as a metabolic agent. Vestn Ross Akad Med Nauk. 2002; (2): 39-41.

5.Geiss, K-R., et al. “Effects of magnesium orotate on exercise tolerance in patients with coronary heart disease.” Cardiovascular drugs and therapy 12.2 (1998): 153-156.


Anxiety and Sleep Medications

Anxiety and sleep medications can be dangerous, especially when used inappropriately. Zolpidem (Ambien) is a very common one that many people take to get to sleep at night. Alprazolam (Xanax) and clonazepam (Valium) are also fairly common drugs that are seen in the pharmacies and in the cupboards of many people. They are taken whenever a person feels anxious, which these days seems like all the time.

Zolpidem is classified as a sedative-hypnotic. It puts you to sleep and that is why so many people like it. Take one sometime before bed and it’s lights out for the next few hours. So what’s the problem?

Zolpidem affects a specific omega-subtype of the GABA receptor in the central nervous system. This subtype is what puts you to sleep but doesn’t seem to affect muscle tone and doesn’t show anxiolytic properties (anti-anxiety). This also may be why so many people have reported all kinds of crazy incidences of sleep walking or other activities without remembering a thing. You can read about some of those here:

As with many receptors it’s also likely that since they are being activated so often by meds like zolpidem they get down regulated with time and people don’t get the benefit of the drug. I’ve talked with several people in the pharmacy about this. They are so frustrated that they can’t get sleep. Some take double the dose that is normally prescribed and still only sleep a couple of hours.

This quite honestly scares me. I’m worried that some people are going to take it too far one day for that one night of sleep and then not wake up. We Americans especially forget that more isn’t better to a problem that actually requires less.

Another problems that scares me is the sharing of these types of meds between family and friends. This is especially true among teenagers. A recent article talks about this:

SAMSHA (Substance Abuse and Mental Health Administration) reported that “the estimated number of emergency department visits involving zolpidem overmedication (taking more than the prescribed amount) nearly doubled from 21,824 visits in 2005-2006 to 42,274 visits in 2009-2010” [1]. By comparison they report that in 2010 there were a total of 4,916,328 drug-related visits to emergency departments throughout the nation.

It’s not the most abused drug in the country but it is on the rise.

Drugs like clonazepam mentioned earlier aren’t so selective as zolpidem and can cause other problems. Originally they were developed for people with seizure disorders and they work well for that. People now take them primarily for finding relief from anxiety and stress.

Like zolpidem, people can become tolerant to them over time and require higher and higher doses to get the desired effect. It’s no different from a person on pain medications. These are more likely to cause a euphoric effect on a person than the zolpidem and many become psychologically dependant. It’s very important to note that people wishing to discontinue these after having been on them for some time must do so slowly. The withdrawal symptoms in people on high enough doses can actually land them in the hospital and cause death. While going cold turkey off narcotics isn’t recommended it typically doesn’t cause death like the benzodiazepines (clonazepam, alprazolam) can.

What can a person do to help with sleep?


Exercise seems to be beneficial to those who have insomnia. In a study with insomniacs, researchers looked at walking on the treadmill for 50 minutes at a time, 3 days a week for 6 months. What they found was that participants were able to fall asleep faster and had decreased amounts of wakefulness during the night. [2] The effect was seen in both the morning and evening groups.

Another study found similar results but the best were achieved in those performing moderate amounts of activity and not all out, balls to the wall type of stuff. It was also done on the treadmill for 50 minute intervals.[3]

In another analysis done in diabetics, the loss of belly fat with diet or exercise or a combination of both resulted in better sleep. [4]

There are other things that can help. Getting into a sleep schedule and actually going to sleep at the same time every day. I know that seems impossible or at best unlikely but it does help.

Managing a proper diet and exercise/activity level also decreases anxiety and symptoms of depression. I realize the catch-22 of people with depression. They don’t want to do anything, especially exercise. They don’t have the energy to do it and even if it makes sense logically that it will help, emotionally they are too drained to even think about it. If that’s you I encourage you to do whatever you can, even if it is walk to the mailbox. Any start is better than nothing.




2.Passos, Giselle Soares, et al. “Effects of moderate aerobic exercise training on chronic primary insomnia.” Sleep medicine 12.10 (2011): 1018-1027.

3.Passos, Giselle S., et al. “Effect of acute physical exercise on patients with chronic primary insomnia.” Journal of clinical sleep medicine: JCSM: official publication of the American Academy of Sleep Medicine 6.3 (2010): 270.