Dr. Chris Masterjohn talks about How to Know if Your Genetics Contribute to Your Sensitivity to Blue Light and Poor Sleep, and What to Do About it

Mastering Nutrition Episode 10: How to Know if Your Genetics Contribute to Your Sensitivity to Blue Light and Poor Sleep, and What to Do About it

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In this episode, I show you how you can determine whether your genetics are contributing to your sensitivity to blue light, poor sleep, and poor daytime alertness, and what you can do about it. Specifically, I look at the research showing that variations in the gene for the vitamin A-dependent protein melanopsin underlie sensitivity to blue light and I teach you how to figure out your own genetics for this protein using a 23andMe account (they don't have a health report for it, but the hack around that is easy).

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Check out the show notes below for references and handy instructions on how to put this material to practical use.

Show Notes for Episode 10

This podcast is also available as a corresponding blog post. Read that post if you prefer to read the material rather than listen, or if you want to follow up the references.

Also check out my original post on melanopsin from a few months ago.

For my own sleep-optimization routine, check out Episode 5.

Since this episode is over an hour long, here is a guide to navigate through it more effectively:

0:00:30 cliff notes for people who want the take-home points in a few mintues
0:04:54 updates on meditation and chicken stock
0:11:20 how to navigate through this podcast and the two related blog posts
0:13:00 background on melanopsin and the other vitamin A-dependent opsins, and their roles in vision, pupillary constriction, and circadian rhythm
0:25:20 entrainment of the circadian rhythm vs. the acute response to light and darkness
0:29:45 the i394T polymorphism in the melanopsin gene
0:33:35 role of the C allele in greater light sensitivity: research methods
0:39:25 role of the C allele in greater light sensitivity: results
0:41:33 practical implications of having the C allele
0:48:50 how to figure out if you have the C allele
0:51:30 how to properly construct a light exposure routine
1:02:20 the importance of temperature and psychological wind-down routines
1:03:45 nutritional factors: A, B6, B12, folate, choline, betaine, protein, carbohydrate, timing

At 31:25, I apologize for the loud sirens. These were crazy loud when I was recording but I don't hear them when listening to my podcast. Do you? If not, that says something good about my recording equipment.

To find your own melanopsin genetics, follow these instructions or use the video below:

  • In the upper right corner of the home screen, click on the drop-down arrow by your name, and select “browse raw data.”
  • Midway down the new page, you will see two text boxes, “Jump to a
    gene” and “Jump to an SNP.” Copy and paste “rs1079610” (without the
    quotes) into the text box to the right of “Jump to an SNP.”
  • Press “Go.”
  • You should see a new page that says “OPN4” on the left and says your
    name and genotype on the right. Under your name, see whether it says
    TT, CT, or CC.
  • If you have one or more C alleles, this indicates increased
    sensitivity to disruptions of the natural light cycle caused by the use
    of artificial lighting.

If you want extra help doing this, use this video, and skip to the 4 minute 15 second mark:


If you want to prioritize your light exposure to hack your sleep, here are links to the products I've found most useful and use myself:

If you learn your melanopsin genetics and have a story to share about whether optimizing your light exposure has or hasn't helped your sleep and alertness, please share your story below! It would be great to use the comments as an easy way to initially crowdsource an inquiry into how strongly the genetics and the anecdotes correlate.

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  1. Dr. Masterjohn,

    I finally ordered just a basic ancestral 23andMe analysis. I have obtained a raw data zip file.

    To make sense of all the raw data, what are the web sites do you recommend to get a further understanding ?

    Thank you very much!

    1. Ann, I recommend 23andMe’s own health reports. The only third party reporting I use right now is StrateGene but I haven’t evaluated all of the ones available yet.

  2. This is the first post on sleep jacks that have me feeling confident I’m gonna make some headway.

    I stopped a Keto diet last year after horrible insomnia and then impact on my thyroid–hashimotos–where my tsh was super low to then high. Oddly, my glucose is great but my insulin was flagged as being low–does this mean not enough carbs??

    My sleep has never returned. No more dabbling for me. I pledge to eat liver 1x a week, add more butter and tallow (can’t tolerate eggs with autoimmune disease). I will up my natto to weekly (was casually eating only before) as well as up my carbs. I have already added vitamin k but it’s not clear how much to use with the liquid form–bottle says 15 drops–is that a typical dose?

    I have very light blue eyes and for the past month have wore blu blockers with any screen time with no impact on my sleep so I feel confident that the nutritional info here is the missing link for me!

    If I’m new to the 23 and me testing as I’ve never done it is it worthwhile in getting helpful info since the FDA’s changes? So many comments here that they weren’t genotyped just wondering.

    So grateful to have found you, Chris!!!!

  3. I’m unfortunately in the group where it says that this SNP is “not genotyped.” Which I find puzzling since I got my data analyzed before the FDA crack-down. Very disappointing! I do seem to have sensitivity to blue light at night. If I don’t wear my blue-blocking glasses, I have a very hard time winding down at night. I was wondering if it’s just because I have become used to the habit after doing it for almost 3 years, but now I’m guessing that I may be at least CT.

  4. Hi Chris,
    forgot to ask how wearing prescription glasses or prescription sunglasses will affect morning exposure to blue light? I am nearly blind without prescription sunglasses. Should I try to walk without glasses anyway?
    Also, I am planning to schedule a consultation with you as soon as I get my lab results back as I have many health issues I should not have, and noone in my family has (they don’t live in the USA). I have lab history since 2008, but want the latest tests. They (health issues) are neurological and I can’t figure it out, but suspect my diet might play a role. I am one of those small boned and always thin women, though curvy, and always looked 10-15 years younger my age. So I age slow, yet ill. A puzzle I try to figure out. My only guess is elevated bilirubin, which is a strong anti-oxidant, may be it slows my aging.

  5. Great podcast Chris,thank you!
    Just like you I have CT, fast coffee metabolizer and tend to accumulate iron. Blue /greu eyes as well. May be we are genetically related after all :).
    Will start the routine soon and will report later.
    My sleep problems have started in the last five years.

  6. Chris – I’m CT. But didn’t need 23andme to tell me about the light sensitivity though it will qualify to my friends (who are clearly TT) that I’m not some crazy person for sleeping in a black room.

    Had had blacked out windows for 10+ years. And blue blocking glasses for 4 years. Growing up our windows were fairly dark.

    I travel a lot (up to 6 months of the year) so have tried every form of eye mask and keep gaffa/duct tape on hand to cover all of the little lights in hotels & other peoples homes.

  7. My 23andMe raw data for rs1079610 says “not genotyped.” 🙁 I would guess I’m a CT or CC…do you know why this wouldn’t be in my raw data? I had my sample analyzed after the analysis was nixed by the FDA and before they were allowed to provide analysis again…do some snp’s just not show up sometimes? I’m disappointed!

  8. Hi Bill,

    The first strategy I would try would be doubling the carb intake.

    However, that is no guarantee of longer sleep. You just told me you wake up feeling rested. Your body will not sleep longer than it feels the need to, so more carbohydrate would only help you sleep longer if you actually need that sleep.

    It is possible you could benefit from more calories. Your bodyfat is low. However, it is not apparent that you have any health problems from what you have written.


  9. Awesome podcast. I am falling a sleep around 9:45 pm and waking up at 5:00 am rested. I would love to sleep an extra hour until 6:00 am but having trouble achieving this goal. I eat a lower carb (50 to 80 grams/day), moderate protein (110 grams/day)and higher fat diet. My caloric intake ranges from 1900 to 2200 per day. I have implemented the light strategies as well as the increasing Vit A via animal sources. I am a 55 year old male weighing 158 lbs at 5" 11" about 10% body fat and work out three times a week. To achieve my goal of sleeping longer do I need to up my carb intake/timing and increase my caloric intake and if so any suggestions?

  10. Thank you for a great podcast. I am quite diligent about walking every morning outside and wearing blue light blocking glasses in the evening. I tried to be in bed by 9:30 to be asleep by 10pm. Unfortunately I still suffer from insomnia. I also have a gene AANAT which I'm not sure you are familiar with but would love your insight. I have both the double C allele for the sensitivity to light that you mentioned in your podcast but also a double mutation for the AANAT which regulates your circadian rhythm. One thing that has helped me is your suggestion to have at least 90g of carbs. I had been waking consistently between 4 and 4:45am. If I wake then, I am better able to fall back asleep now but sleep is still a problem as I don't ever wake up feeling rested. My acupuncturist also noticed my tongue being on the blue side – lack of Oxygen, she says. I don't think I snore or have sleep apnea as I'm 108 pounds, 5'2" female, but I am going to go for a sleep study soon. I've been dealing with insomnia for several years and would really love to learn what I need to do to get better. Can you discuss your views on chronic infections such as mycoplasma pneumonia and Epstein Barr as it relates to sleep?
    Thank you! I am so happy to have found your podcast from Ben Greenfield's podcast. I needed more technical info as I'm getting my masters in clinical nutrition.

    1. Hi FUEL4U,

      AANAT is involved in melatonin synthesis. Could you please provide the specific rs number of the mutation you have, and what alleles you have (by alleles, I mean the letters, like A, T, G, or C)?

      I'm glad the carbs are helping. I might be able to address the infections but that would be a ways out.


    2. RS74466028 CC
      RS74463109 TT
      RS74456758 CC
      RS74454668 TT

      What is your recommendation for helping get rid of the anxiety related to falling asleep. Often I'm tired all day but then if I don't fall asleep in a 15-30 minutes, I get a 2nd wind and then it's hours before I can wind down again.

    3. Hi Fuel4U,

      SNPedia doesn't have anything listed for those, so it would seem there is no research related to them. It is not clear whether these have any meaning.

      I don't think I can offer you detailed recommendations in this context. Anxiety could be caused by too many factors. I have described the importance of light, temperature, and psychologically winding down and given examples of what I do. If you do not have a psychologically winding down routine, you need to make one. If you do, then I suspect you have physiological issues that could have genetic, nutritional, or other roots but they are too diverse to sort out in blog comments.


  11. Christopher, Anonymous, and Brad, yes that is a pity. They say it is because they periodically update the chip they use to optimize better what they give reports on, sometimes at the sacrifice of SNPs they don't report on. I wish there were a way for accounts made in the last few years to get it, but there apparently isn't.


  12. A pity; no results found for this snip in my results. Would have loved to know my genotype.

  13. Hi Chris,

    You should check out the rs5751876 snp as it could also explain your preference towards coffee. CC genotype associated with caffeine sensitivity and sleep impairment from caffeine–people with this genotype also had a higher "caffeine effect score" i.e. the difference between caffeine and placebo on psychomotor vigilance tasks after sleep loss.

  14. uuuuggggh mine says it was not genotyped 🙁

    Not genotyped: 23andMe periodically updates its DNA analysis platform to take advantage of improvements in technology. Customers tested on different versions of the platform will not have been genotyped for variants that are not included on that specific platform. For these customers, results for these variants appear in Browse Raw Data and other features as "Not Genotyped".

    1. **Update**
      I emailed 23andme about not having this in my report. Looks like you won't get this information on their current version. This was the response:

      Thank you for contacting the 23andMe Team. rs1079610 is not included on our current genotyping chip.
      Our records indicate that you are on the most current version of our platform, v4. If a friend were to purchase a kit or if you were to be tested again, you would not see a genotype call at this SNP. We apologize for the inconvenience.

      It is important to understand that the 23andMe Browse Raw Data feature is suitable only for research, educational, and informational use and not for medical or other use. While 23andMe raw data has undergone a general quality review, only a subset of markers have been individually validated for accuracy.

    2. Thanks Lora!

      I think I might get a second 23andMe swab so I can compare what people who got it recently will get with what people who got it when I originally did will get when I make future videos.


    3. Just tried to get my genotype as well and mine also was not shown due to the same response listed above for Lora. My test came back 4 weeks ago so this is recent.

    4. I also have the new on, but if you type in OPN4 into the search Gen box, it shows the OPN4 either with A or G – does this say anything?
      thanks Chris

    5. Hi Sanjula,

      Hmm, I'm not sure what that means. However, it may mean nothing at all. Just because something is polymorphic and they determined your allele doesn't mean it has any functional significance. This does not appear to be one of the SNPs identified in the literature as important.


  15. CT, brown eyed, originally from Northern Finland but with mixed ancestry (Germany, Russia) according to family history, ancestry data and HLA genes.
    I cannot sleep well without black out curtains but they do not salvage if stress management (meditation) and diet(enough carbs/calories according to activity/exercise levels) are not in place. Flux, dim lights, and sauna/hot shower before sleep.
    Freelancing ables to go outside walking morning/noon.

  16. Hi Chris! Thanks for another super informative podcast! I've been using most of the strategies you discussed for a couple of years now in an effort to shift from a "night owl" to a "early bird." I've made progress, but am still working on it. I had never heard of the genetic connection. I actually just received my 23andme results back last week and was excited to check out this possible connection. Unfortunately, with all the changes they've made, it looks like they no longer offer info on the rs1079610 SNP. It says "not genotyped" when I searched for it. Bummer. (Also, note that the interface is different when I log into 23andme. I noticed in your video 23andme says "we will soon transition your account to the new 23andme experience" so it looks like you made this video before some changes were made???) I did run my raw data through the tool on FoundMyFitness.com and apparently have issues with the BCMO1 gene, which seems to affect Vitamin A. These are the SNPs it listed: rs12934922(A;T) rs7501331(T;T). I'm wondering if these are related? This genetics stuff is all new to me, but I'm fascinated by it.
    Not to hijack the comments, but I have another genetics related question. Do you know which SNP(s) I should look at to see if I have familial hypercholesterolemia. I emailed you about it earlier, but now that I have my 23andme data, I thought I might be able to get more info before I meet with my new doctor.
    Thanks again for all you do!!!

    1. Hi Melissa,

      SNP in the BCMO1 probably means you are less efficient at deriving vitamin A from plant products and more dependent on getting vitamin A from animal products. Best way to do that is work liver into your diet.

      23andMe has a report on cholesterol, so I would start there. However, I'm not sure if it's available in the post-FDA 23andMe.

      You can run your raw data through prometheus to get cholesterol-related results. That would probably be easiest.

      In the future I'll try to collect the relevant SNPs and give my input for managing them.


  17. Hi Chris,

    Great podcast! I checked my 23andMe data and found I am heterozygous (CT) for this SNP. I have been using f.lux on my laptop, blue blocking glasses at night, and replaced many of my bulbs to those from lowbluelights.com for a few years now. I certainly have noticed a difference, both in how quickly I fall asleep and in quality of sleep at night. It's not always great, such as when I've had more alcohol than I'm used to, but it has been a great life-hack.

    Hey, as I was listening to your discussion of the role of Vitamin A in transducing light into neural energy through the opsin proteins, it occurred to me to that Vitamin A might play a similar role in olfaction. The olfactory system uses a receptor that is structurally very similar to opsin. Just thinking out loud.

    Keep up the great podcast and I'll see you in August at AHS16.

  18. My husband and I are both CC!! I thought we would be TT! Very strange. I have had red lights installed in alternate light sources all over the house for a couple of years. At first I was switching to them a couple of hours before bedtime, but I was ready to fall asleep too early, so I backed it up. My husband sleeps well most of the time no matter what.

    I almost always fall asleep easily and quickly and sleep solidly for 3 to 4 hours and then sometimes get another couple hours of pretty good sleep and other times, toss and turn.

    I have been experimenting with supplements listed in the post below. By the way, he is just researching for his own sake and sharing with the rest of us. If you buy the supplements through his links, he gets NO compensation; they are not affiliate links.


    I also take magnesium to bowel tolerance and Carlson's Vitamin A from 25,000 to 100,000 iu depending on my allergies. I've been on 100,000 for several months now. I can't eat liver because it gives me a headache. I think it is the choline, because choline supplements also give me a headache.

    The main causes of my early awakenings are food intolerances which either wake me up with a headache or slight gut dysbiosis or pain from my shoulders or hip, which I am working on also. Melatonin gives me a headache, even 1 mg TR. I'm going to try cutting it in quarters to see if that helps. I DOES help me stay asleep (only TR), but I don't like the mild headache.

    Chris, thank you so much for mentioning that it's okay to use non-blue screens in the evening!!! My best routine is to watch a show or two on a tv with a red film over it or the DriftTV attached and then play Words with Friends for a few minutes. The phone sometimes literally falls on my face from me falling asleep. I need the brain distraction of TV then games.

    I LOVE your podcast! Keep it up and THANKS!! I put a thread in the FB Perfect Health Diet Group if you want to check it out.

    1. Hi ReneeAnn,

      Thanks for the great feedback!

      I'm sure those supplements are useful, but they strike me as bandaid solutions. I used to use chronic time-release melatonin and since I've fixed my vitamin A nutrition and instituted a better light-based routine I haven't taken melatonin in almost a year.

      Food intolerances are certainly worth addressing. I am inclined to think waking up early largely comes down to not eating enough calories and/or carbohydrate.


    2. I wonder if a lot of people who didn't live a healthy lifestyle earlier in life need the bandaid supplements as we age? I should say, I'm 55, so aging is a factor. And, chronic pain is hard to overcome, too, making it difficult to sleep after a while.

      I stack my carbs for the second half of the day to help sleep. I think I eat enough calories, but I don't track calories. I do make sure that I eat at least 2 4oz servings of meat per day and 9 servings of fruit and/or vegetables. In addition, I usually have about 6 ounces of sweet potato starch noodles and some gluten free pancakes for evening dessert. Oh, and a square of chocolate for breakfast.

      Being post-menopausal, I believe I would gain weight if I added more food. I'm the upper end of normal weight and don't want to cross over that. 😉

      Thanks for your comments.

  19. hi does it change if you live in uk as I dont get result on the snp you list when i search under OPN4 it shows me as gg
    why is this different and what does GG show please.
    thanks marcus

  20. Maybe vitamin D and magnesium play a role in all of this. I develop light sensitivity, anxiety, sleeping problems and headaches from too much calcium, vitamin D or sunshine, but magnesium relieves all of this. Wouldn´t high intakes of vitamin A antagonize vitamin D?


    1. Vitamin D does play a role in sleep and Mg plays a role in everything. Sounds to me like you have a chronic Mg deficiency. A and K may help if it is related to soft tissue calcification, but if it is related to poor control over the subcellular localization of calcium, it is mainly Mg that will help.


  21. "CC" genotype. I am very sensitive to the light affecting my sleep. I have black out curtains. I put on the amber safety glasses about an hour before sleep and turn down the lights. I tried to avoid using the computer before sleep. I learned from not doing these things that they affect my sleep.

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