Chill out with melatonin-laced brownies?

By Karyn O'Keeffe 18/05/2011 4


To the casual observer, it may appear that some months ago I started to blog on sleep, wrote a few posts… and then simply disappeared from the blogosphere.  Unfortunately, April was a month of over-commitment on my part (I’m really good at that).  But, I’m back…

During the last few days, my Google reader has been filled with reports of a controversial new brownie (‘Lazy Cakes’) available for sale in the United States.  This latest edition adds to a range of baked goods and/or dietary supplements aimed to promote relaxation and therefore supposedly, sleep.

Sold at supermarkets, and department and convenience stores, Lazy Cakes contain ingredients the manufacturers believe promote relaxation, such as valerian root, rose hips and melatonin.  Although not explicitly cited on the Lazy Cakes website, web commentary has suggested that these products may be used to promote sleep.  Certainly, a New York Times article cites individuals with insomnia who have tried Lazy Cakes.  Much of the web discussion at present has centred on the use of melatonin in these brownies and in particularly, the reasonably high dose of 8mg melatonin per brownie.

There is considerable concern about taking melatonin as a dietary supplement.  Melatonin is a neurohormone that interacts with a number of systems in the body, of which only one is the circadian (body clock) system.  It also has a significant role in the control of our reproductive function, thermoregulation, thyroid function, carbohydrate and lipid metabolism, urine output, immune function… the list goes on.

Many people associate melatonin with a sleep-promoting hormone because it is secreted at night (coincidentally when humans sleep) and suppressed by light during the day.  In fact, melatonin is secreted at night regardless of whether we are diurnal (active during the day) or nocturnal (active at night).  When it comes to sleep/wake information, melatonin’s main role is to tell us what time of day it is.  Melatonin also changes seasonally in all mammals (including humans) so it can also tell mammals what time of year it is, which is important for reproduction and hibernation.

Many studies have considered the influence of melatonin on our sleep timing and quality.  In humans;

  • Melatonin’s main action is in its ability to shift the timing of our sleep by changing the timing of our body clock.  This means that taken at the wrong time of the day, melatonin may shift the timing of your sleep to an undesirable time.  Timing instructions do not come on the packets/bottles of melatonin-containing products.  Would you know exactly when you should be administering melatonin to optimise your sleep timing?
  • Melatonin has no effect on sleep quantity or quality when used as a sleep aid.
  • Timed appropriately, melatonin can shorten the time it takes you to fall asleep but in healthy adults, this effect is usually incredibly small (something like 4 minutes on average; statistically significant but not clinically significant).  It does seem to be more effective at reducing the time it takes to fall asleep in those with insomnia, but it still does not change sleep quantity or quality in this group.
  • Acute side effects include, commonly, headache and taken during the active day, sleepiness and fatigue.
  • We do not know the long-term risks associated with frequent administration or inappropriate timing of melatonin.  At present, the greatest concern lies with its effect on our reproductive function, including reproductive cancers.

To the general public, melatonin is usually promoted as a product for those who are having trouble sleeping, including those with insomnia.  As someone who is not an advocate for pharmacologic treatment for chronic insomnia, if it were me, would I regularly take dietary supplements containing melatonin to improve my sleep?  Not on your life.


4 Responses to “Chill out with melatonin-laced brownies?”

  • Would be interested in you opinion on the use of it for travel to the other side of the world to offset jetlag. The last few times I did this (sport you see) I have swilled a tablet at local (over there) evening time to try and fool my clock into sleep mode. I did it for the first two nights. Of course, I took the added precaution of ensuring I did not take naps during the day and got up early to let the sun hit my tender skin. So I am sure that doing both has not helped in the decision of which worked best!!…….or not at all…..

    • OK, theory first and then practicalities…

      In theory, melatonin can be used to treat jet lag and is most effective when making the best use of exposure to bright light (sunlight) and social cues in the new time zone. The timing of administration needs to be individually tailored taking into account a number of different factors: the current timing of your circadian rhythms, the length of your flight, the number of time zones crossed and the current time in the new location. This means that for optimal shifting of your circadian rhythms, you would not universally take melatonin in the evening. Instead, you would theoretically calculate when you need to take it based on the factors above. The time that you would take melatonin and the time you would expose yourself to light would change every time you travel. Accidentally taking melatonin or exposing yourself to light at the wrong time can, in fact, send your circadian rhythms in the wrong direction so you have to shift everything the long way round.

      That said, there is evidence that repeatedly taking melatonin close to bedtime in the new time zone is effective at decreasing jet lag symptoms. It’s a fairly crude way of doing things and wouldn’t optimise the shifting of circadian rhythms but given enough days in the new time zone, it would certainly work. And in most cases it’s the only option you have.

      The problem with melatonin administration is that it causes sleepiness so regardless of optimal timing with circadian rhythms, it is not sensible to take it during the day in your new time zone. The key really is exposure to sunlight. Sunlight is the strongest input into our body clock controller and has the greatest effect on shifting its timing. So… repeatedly taking melatonin at night, over enough nights, with (most importantly) individually tailored exposure to light (this could be morning/noon/night and you would need to calculate this each time) and careful control of your sleep/wake schedule, would alleviate jet lag symptoms.

      Sorry, that’s a lengthy answer… hope it helps.

  • Thanks Karyn for the reply. I am thinking of trips within 24 -36 hours to the Europe. A regular occurance for scientists travelling to conferences etc, so the travelling bit is practically continuous. I think what you are saying is that depending on where you are in that travel, you take it “just before bedtime” at the final destination. And stay out of the sun! Given my reading of ganglion eye cells that connect to the circadian rythms and their blue sensitivity, would yellow sunglasses be enough to suggest to these cells that it is not daylight?

    My expereince of aircraft is that they LOVE to pull the blinds closed so lots of trips are done “in the dark” anyway.

    The other titbit I heard a few years ago was that sunlight at 5 am has the biggest effect on clock turning?????

    • Hi Ross. Not quite. You definitely want to expose yourself to light! In fact, timed light exposure would much more effective at shifting your circadian rhythms than any crude overexposure to melatonin at bedtime.

      The evidence suggests that exposure to melatonin alleviates jet lag symptoms compared to none (it does not suggest melatonin is better than timed light exposure); melatonin tricks your body into thinking its night. But… that doesn’t mean that your subsequent sleep is good quality or that your circadian rhythms are shifting optimally. It just means it’s easier to get to sleep right then. You could have awful sleep. It certainly doesn’t guarantee optimal functioning as required for conference presentations and sport performance. Additionally, it works most effectively when you want to make your circadian rhythms occur earlier. If you need to delay your rhythms, melatonin alone is not very good at helping with jet lag at all.

      I don’t use melatonin when I travel to conferences, I use light.

      I agree that the whole picture is quite complex though. Your jet lag symptoms will depend on your light exposure in the new time zone primarily, your sleep/wake schedule both before you left and in the new time zone, your willingness to adapt to local time cues, the amount of sleep you got on the plane, the time your flight left, the length of your flight, the time your flight arrived and the direction you flew in (east/west). That’s a lot of factors to consider… It’s also important to bear in mind that jet lag symptoms are not only related to circadian rhythms (although that’s the primary mechanism) but also influenced by our overall sleep drive (another sleep control system altogether).

      On arriving in your new time zone, you would work out when you need to expose yourself to light to shift your circadian rhythms forward or back, in addition to exposing yourself to the usual day/night light of the new time zone. Essentially you give yourself usual day/night light exposure but you make sure you definitely get exposure to light at particular times of the day so that you can also shift your rhythms. I would love to give you an example, but it depends on all those factors above. You work out your light exposure for each individual trip. Sometimes you’d need to be up earlier than usual, sometimes you’d need light during the usual business day, sometimes you’d need extra walks in the evening.

      Sunglasses are usually effective enough at limiting exposure to unwanted light. Indoor light does not produce as strong a shift in circadian rhythms. The answer to the 5am question is complex – and it seems I’ve already written enough 🙂 Very short answer and not particularly informative answer… not really.