In a recent bizarre interview, singer Mariah Carey revealed that she bathes in milk as a 'beauty treatment'.
While a bath in cold milk doesn't sound like the most relaxing activity - this is one instance where the diva offers sound advice.
Milk contains healthy fats and proteins and is rich in vitamins and minerals that help remove dead skin cells, prevent wrinkles and improve complexion.
New York City dermatologist Dr Douglas Altchek spoke to Daily Mail Online about how the properties in milk work to nourish skin, how long you should stay in the bath and even the type of milk that's best to use.
Milk baths, like the one singer Mariah Carey (pictured), takes could actually be good for you, because it is rich in vitamins and minerals that help nourish skin, New York City dermatologist Dr Douglas Altcheck told Daily Mail Online
MILK'S HEALING PROPERTIES
Legend says that Egyptian queen Cleopatra bathed daily in sour donkey's milk to improve the complexion of her skin and reduce wrinkles.
Dr Altchek doesn't recommend bathing in rotted milk, but says the dairy product does contain protein and skin-nourishing minerals like vitamin E and zinc.
Vitamin E neutralizes the effect of free radicals, which are molecules that cause skin dryness, fine lines and wrinkles. They also damage collagen, or the connective tissues that keep your skin together.
Meanwhile, Vitamin D has been shown to minimize acne, increase skin elasticity, and lessen the appearance of dark spots.
Dr Altcheck also says that the two vitamins have healing properties.
'Vitamin D and vitamin E will also help accelerate how fast the skin repairs itself from UV rays, wind, sun, contaminants and pollution,' he told Daily Mail Online.
The dermatologist adds that another key ingredient in milk, lactic acid, also has skincare benefits.
'Lactic acid is a healing product which helps the skin become smoother,' he said.
Legend says that Egyptian queen Cleopatra bathed daily in sour donkey's milk to improve the complexion of her skin and reduce wrinkles.
Lactic acid is an alpha hydroxy acid, which encourages the skin to shed its old, dead skin cells to reveal the new, healthy skin cells hidden underneath.
In higher concentrations, it also works to reduce pigmentation and brighten the skin.
HOW TO DRAW YOUR BATH
Dr Altcheck says that it's better to use warm milk because it will penetrate the skin faster than cold milk - but warns against staying in the bath for too long.
'It's a double-edged sword because on one hand you want to stay in there long enough to absorb the nutrients,' he said.
On the other hand, you will become dehydrated if you stay in too long and the water will literally roll out your skin. I would say anything beyond 15 minutes would be harmful.'
WHAT TYPE OF MILK SHOULD YOU USE
As for the types of milk, Dr Altchek recommends going with an option that is higher in fat content.
On the glycemic index chart, which indicates how much a carbohydrate-containing food raises your blood-sugar levels, skim milk has a level of 32 while whole milk has a level of about 27.
Foods that are higher in glycemic index elevate hormones that increase the activity of oil glands in the skin, which could contribute to acne formation.
High glycemic foods also cause prematurely-aged collagen, which causes the skin to lose its elasticity and become more fragile.
However, the best milk option, according to Dr Altchek, is buttermilk.
Buttermilk is laden in lactic acid, which helps a number of skin-related issues including sloughing off dead skin cells, lightening age spots and tightening skin.
'Buttermilk has the highest lactic acid in it and will be more emollient to the skin,' Dr Altcheck said.
He adds that animals, including pigs and dogs, are often bathed in buttermilk to soften and nourish their skin.
'If it’s good enough for the pigs and dogs, it's good enough for us,' said Dr Altchek.
Once the bath is done, Dr Altchek says to rinse off thoroughly - because milk decomposes quickly and you could end up smelling like rotten milk - and moisturize your skin.
Dr Altcheck recommends choosing buttermilk for a milk bath because it is high in lactic acid, which helps a number of skin-related issues including sloughing off dead skin cells
OTHER BENEFITS FROM MILK
Milk has more than just skin-nourishing benefits, it can also aid in easing suburns.
In a previous interview with Daily Mail Online, Dr Joshua Zeichner said a cold milk compress shrinks the cells swollen from the burn and will drive heat away from the sore area.
'A milk compress can help calm inflamed skin as well, as proteins in the milk coat and soothe the skin,' he said.
The lactic acid in milk will help peel away the inflamed, dead skin cells while vitamins A and D promote healing.
For the compress, pour the milk in a bowl, soak a washcloth in the mixture and refrigerate until both are cold.