ask scienceline | health
Is it true that warm milk can make me sleepy?
–asks M.L. Ribindrandy from Seneca, NY.
It’s not utterly out of the question. Like most old wives’ tales, there’s some scientific support for warm milk’s slumber-inducing capacity.
First, let’s tackle the most likely suspect: warmth. Warmth lulls most mammals off to dreamland, but not from within the body. Many behaviorists have noted that mammals nod off when warm, especially after a satisfying meal and a snuggle. So, is drinking in the warmth of delicious dairy enough to have any effect on us?
Maybe, but it would work even better if you bathed in it. According to Progress in Brain Research, a sleep textbook published by the Netherlands Institute for Neuroscience in 2006, sleep is induced more rapidly when skin temperature rises. (On a tangential note, if you do decide to bathe in milk, the lactic acid in the beverage is said to soften and exfoliate skin. But don’t expect to swim in the moo juice on the cheap. A milk bath in the swank spas of New York City can run you $600.) Having a glass of warm milk in your gut is unlikely to raise skin temperature enough to have any effect. So, cross “warmth” of the list. But what about milk’s nutritional properties?
Most people have heard of tryptophan in relation to Thanksgiving—this essential amino acid (a building block of proteins) is responsible for that inevitable nap after a big turkey dinner. Consuming foods that contain tryptophan has long been linked to sleepiness, and it turns out there are traces of the chemical in milk as well as turkey. In the body, tryptophan is converted to the sleep-inducing hormones serotonin and melatonin. But the amount of tryptophan in any food—including both milk and turkey—is not large enough to boost hormone levels so high that they would induce sleep.
Don’t fret, though—if you have been relying on a luscious lactose nightcap for a good snooze, you don’t have to downgrade from gallons to quarts so fast. There might not be a strong biochemical link between warm milk and sleep, but there may be a psychological one.
Infants often go right to sleep after breastfeeding. When an adult enjoys a warm glass of milk they may just be taking an unconscious, nostalgic trip back to this “happy place.” Who doesn’t enjoy a good suckle?
A study published in a recent issue of Neuroendocrinology Letters found that infants go to sleep faster after feedings. While no research has yet examined this phenomenon in adults, it’s not unreasonable to suggest that milk-guzzling grown-ups are unconsciously reminded of an infantile state which causes them to drift off.
So, if you enjoy drinking a little of the white stuff to make you pass out, go right ahead. It may be possible that you have conditioned yourself to the behavior, and drinking it really does help you sleep. There’s probably not much going on chemically—it’s more like a placebo effect. But remember, the only way for a placebo effect to work is if you keep on believing.
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October 12th, 2006 at 12:18 pm
“While no research has yet examined this phenomenon in adults . . . .”
Um, what might that study look like?
October 12th, 2006 at 12:26 pm
Also, aside from your anglophillic preoccupation with cow and people milk, airag, also known as koumiss, is a milky beverage that is almost certain to make you sleepy, no matter what time of day you do the imbibing.
October 12th, 2006 at 10:00 pm
Beach - I’m not sure what you are asking in your first post. As I said, there is no study that has examined the psychological link between drinking milk before bed-time and breast feeding as an infant. Please clarify.
As far as your second post: ok.
Um, thanks for your input.
November 24th, 2006 at 10:46 pm
I think beach is really funny.
December 11th, 2006 at 2:05 am
Yeah, I thought the same thing when I read beach’s first comment, then I realized it was a…joke. The second comment…if koumiss happens to contain the 1-2% alcohol it’s supposed to, will sedate you at first, sure, but alcohol later acts as a stimulant and wakes you up. So…not the best advice there.
Thanks for the info, as I look at my “can’t say it does or doesn’t work” warm glass of moo juice…I’m thinking a warm bath would also be nice.
December 29th, 2006 at 3:15 am
Milk is soothing.. i cook it on a hot pan..i wouldnt say it makes u sleepy but the effect it has is this. first off all of the stuff said by scientist or whatnot is true. but from a phycologist stand point. i would have to say its a comfort zone, if ur having trouble sleep ext. u make the milk warm u sit and drink and in the process ur forgetting the thing bothering you, and u may find stress to be releaved by just doing this simple task. boiling milk, pouring it, drinking it. same for tea..but at 2 AM and ur having a rough one try anything and stay happy
PHILBERT
September 3rd, 2007 at 9:06 pm
i drink a glass every night i think it works like sleeping pills
i wake up in the morning not 2 tierd and ready for school
June 3rd, 2008 at 5:34 pm
Milk spoils. If I can’t sleep i’ll just reach for the Jameson on my nightstand and start goin to town. If that doesn’t work i’ll crunch down a couple of xanax. Guaranteed TKO.
July 28th, 2008 at 2:45 am
you smell
August 14th, 2008 at 12:07 am
I drink hot cocoa to get me to sleep. When I drink it, a calm feeling helps me. The Caffeine doesn’t bother me. It’s warm and it works for me. When I try to go to bed early, I cannot. I’ve got into this habit of staying up real late and exhausted when I wake up in the morning even when I’m at work. I use Valerian every once in a while, but I don’t want to be too dependent on it. I have a condition in which stress is my enemy and if it comes, I’m scratching the back of my neck. I know what this is and how to treat it. It’s Psoriasis. Terrible when it’s into its mild stage.
August 22nd, 2008 at 11:31 pm
i am only 10 and i cant sleep at night! theres no stress on me and it is like i am not even tired
September 10th, 2008 at 7:07 am
The warm milk made me sleepy for like 5 minutes but I couldn’t go to sleep. I think I have insomnia.
October 15th, 2008 at 9:59 pm
a glass of warm milk, mix with cream and a little hunny…puts me right to sleep
December 6th, 2008 at 8:45 am
There is another reason why milk makes some people tired. 75 % of the worlds population is lactose intolerant- least in N. Europe and more as you move away from there. Nearly 1/3 of people with lactose intolerance have noticeable tiredness when they consume dairy. This is because excess lactose in the body causes tiredness (physiological). Milk has more lactose per serving than other dairy (much more). Often about half the people who test poor on diagnostic test for lactose digestion are unaware that their body is not digesting the lactose properly (this is consistent in many Epidemiological studies- so this can happen even if you don’t know your lactose intolerant. I became very symptomatic for lactose intolerance in my thirties and milk always makes me tired now- warm or cold.