Is cold milk good before bed?

Milk has long been associated with better sleep, with the old adage of drinking a warm glass before bed persisting for generations. But does the temperature of the milk really matter when it comes to improving sleep? Let’s take a closer look at whether cold milk could also be an effective bedtime drink.

The science behind milk and sleep

First, we need to understand why milk is believed to help sleep in the first place. Milk contains several compounds and nutrients that have been linked to better sleep quality:

  • Tryptophan – An amino acid that is used by the body to produce serotonin and melatonin, hormones that regulate sleep.
  • Calcium – Mineral needed for nerve and muscle function, including contraction and relaxation of muscles.
  • Magnesium – Mineral that acts as a muscle relaxant.
  • Potassium – Mineral that helps regulate fluid balance, which may promote relaxation.

The tryptophan, calcium, magnesium, and potassium in milk help initiate sleepiness and reduce muscle tension, setting the stage for deeper, more restorative sleep. The warmth of milk may help by promoting relaxation as well.

Does milk temperature matter?

Now this begs the question – does the milk need to be warm to obtain those benefits? Or can cold milk be just as effective?

There hasn’t been extensive research comparing the effects of cold versus warm milk before bed. But looking at the components of milk, there are reasons to believe lower temperatures could also be beneficial:

  • Cold temperature may not reduce tryptophan levels – The tryptophan in milk is the main driver of increased serotonin. Cold temperatures don’t degrade tryptophan like they can other proteins, so tryptophan levels should remain steady in cold milk.
  • Cold milk may be more palatable – Some people dislike warm or hot drinks before bed. The cold temperature may make drinking a glass of milk more enjoyable and easier to finish.
  • Cold may promote deeper body temperature drop – Body temperature naturally declines at the onset of sleep. Cold milk could accentuate this drop in core body temperature.

Theoretically, cold milk contains the same sleep-promoting compounds and could offer additional mechanisms like easier ingestion and body cooling. But more studies are still needed comparing the effects directly.

Other possible benefits of cold milk

Drinking cold milk could have other advantages as well:

  • More hydrating – Cold milk may be more hydrating than warmer milk, which could help prevent headaches, dry mouth, and grogginess in the morning.
  • More energizing – The cool temperature may be more refreshing and energizing than warm milk, making it a better daytime beverage.
  • More versatile – Cold milk can be used in smoothies, protein shakes, cereal, or enjoyed on its own. It offers more flexibility than warm milk.

While warm milk is traditionally linked to bedtime, cold milk may offer additional perks in terms of hydration, energy, and ways to consume it. This expands the scenarios in which milk could benefit your diet and lifestyle.

Potential downsides of cold milk

Are there any potential cons to drinking cold milk before bed compared to warm milk? A few to consider:

  • Less soothing – Warm milk has intrinsic comforting, soothing properties that cold milk lacks.
  • Possible digestive issues – Cold temperature could theoretically slow digestion. But there’s little evidence that chilled milk causes significant digestive problems.
  • Not ideal taste – Milk flavors may be more pronounced at colder vs. warmer temperatures. Some people may find very cold milk unpleasant to drink.

The biggest disadvantage is probably the lack of inherent soothing effects. But convenience and palatability may outweigh that drawback for many people.

Best practices for drinking cold milk before bed

If you want to experiment with ice-cold milk as a nighttime drink, here are some best practices to consider:

  • Drink it 2-3 hours before bed – Give your body time to digest it properly.
  • Select reduced-fat milk – The fat in whole milk could be harder to break down when chilled.
  • Sip slowly – Drinking quickly may cause indigestion or discomfort.
  • Pair it with sleep-friendly snacks – Like crackers, nuts, or banana to aid digestion.
  • Stick to 8 oz or less – Too much liquid close to bedtime can disrupt sleep.

Following these tips can help minimize any potential downsides of cold milk at night. Adjust the quantity and pairings based on your individual tolerance.

The bottom line

There’s no definitive research yet on how cold milk compares to warm milk in promoting better sleep. But cold milk contains the same beneficial compounds and, theoretically, offers its own advantages like increased hydration, energy, and convenience. If you prefer drinking cold milk or can’t easily warm it, it can still be an option worth trying before bed. Follow sensible portion sizes and timing, and adjust the temperature and additions to match your personal preferences.

Pros of Cold Milk Before Bed Cons of Cold Milk Before Bed
May still contain tryptophan Less inherently soothing
Easy and convenient to drink Could cause minor digestive issues
Promotes body temperature drop Taste or thickness may be off-putting
Energizing for daytime
More versatility in recipes and uses

Frequently Asked Questions

Is cold or warm milk better for helping you sleep?

There is no clear research showing whether cold or warm milk is definitively better for sleep. The active compounds like tryptophan are present in both cold and warm milk. However, warm milk may be more soothing and relaxing due to its temperature. But cold milk has upsides like increased hydration and convenience. Overall, it likely comes down to personal preference.

Why do people drink warm milk before bed?

People often drink warm milk before bed because of its reputation for inducing sleepiness. The warmth is thought to have an innate calming, soothing effect. Warm milk also contains compounds like tryptophan, calcium, and magnesium that can physically relax muscles and nerves. The ritual of drinking warm milk may also signal to the brain and body that it’s time for rest.

Does chilled milk make it harder to sleep?

There’s little evidence that chilled milk makes it significantly harder to fall or stay asleep compared to warm milk. Cold milk still contains tryptophan and minerals that induce sleepiness. Some people report sleeping fine after drinking cold milk. Any digestive discomfort could be avoided by drinking it slowly, several hours before bed. But more studies directly comparing temperature effects are needed.

Can I drink cold milk if I have acid reflux?

Those with acid reflux or gastroesophageal reflux disease (GERD) may want to take some extra precautions when drinking cold milk. The colder temperature could potentially exacerbate symptoms like heartburn. Those with reflux may want to stick to smaller portions of cold milk and avoid drinking it right before laying down. Adding a spoonful of yogurt may help boost good gut bacteria to aid digestion.

Is it OK to combine cold milk with cookies or cereal before bed?

It’s generally fine to pair cold milk with a small snack like cookies or cereal before bed. In fact, combining milk with a fibrous, filling food like whole-grain cereal could actually help mitigate digestive issues. Just be mindful of portion sizes – a large glass of milk and big bowl of cereal could be hard to digest all at once. Start with smaller amounts and give your body time to properly break down the food.


While warm milk is often recommended for better sleep, the evidence for cold milk’s effects is less clear. Cold milk provides many of the same sleep-promoting compounds and minerals that may relax the body. It also offers perks like hydration and ease of consumption. Cold milk can be reasonably consumed before bed as long as you follow smart practices like moderate portion sizes, drinking early, and pairing with snacks. More direct research studies could shed light on the bioactive properties of milk at different temperatures. But in general, cold milk remains an option if you prefer it over heated milk at night.

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