The beauty enhancing properties of milk have been known and documented for thousands of years. Legend has it that, in ancient Egypt, Queen Cleopatra regularly bathed in goat's milk to retain her youthful appearance. In the 21st century, milk remains a useful beauty ingredient that delivers nutrients and enzymes to improve the appearance of tired, aging, or irritated skin.
Milk is produced by mammals as the primary source of nutrition for their young. As a result, milk is packed with vitamins, minerals, protein, and carbohydrate, which are essential for the growth and development of a young mammal.
Topical application of milk brings out the natural beauty of skin. Milk contains lactic acid, an alpha hydroxy acid (AHA) that exfoliates the skin, removing dead cells from the skin's surface and promoting the generation of fresh skin cells. Regular application of milk to the skin encourages the skin's natural regeneration process. AHAs in milk also help to reduce the depth of the fine lines and wrinkles caused by skin aging. AHAs slough off the dead skin cells that cling to the skin's surface and stimulate collagen production, which diminishes the appearance of lines and wrinkles.
Whole milk is an effective skin conditioner. Fat molecules in whole milk nourish and hydrate the skin, leaving it soft and supple. Low-fat and skim milk have the fat content removed, meaning they lack the skin conditioning properties of whole milk.
Topical application of milk can lighten skin pigmentation by approximately half a shade. Results are temporary and milk must be applied to the skin regularly to maintain the results. Skin that has been irritated by sun exposure or by skin conditions such as eczema can be soothed by application of whole milk in the form of a compress.
The amino acids found in milk can nourish hair, which is made of protein. In particular, glutamine stimulates hair follicle growth, making milk protein a useful ingredient in hair thickening products.
Consumption of milk as part of a healthy diet can also improve the condition of the skin. Milk is a natural source of vitamin A, which helps to combat the effects of aging by stimulating cell regeneration. Milk is also high in zinc, which has been proven to improve the appearance of skin acne in clinical trials. However, in some individuals, milk can exacerbate acne outbreaks. In these cases, consumption of milk should be avoided.
The protein content of milk helps to maintain healthy body tissue. As milk can be obtained in low-fat and fat-free versions, it is a healthier source of protein than red meat, which contains saturated fat that can clog the arteries. Milk contains amino acids, which are the building blocks of proteins. Tryptophan is an amino acid that has been shown to improve wellbeing and mood by stimulating the production of serotonin in the brain. Serotonin has a calming and relaxing effect. Tryptophan is thought to promote sleep. Perhaps this is one reason why warm milk makes an ideal bedtime drink.
Milk is high in calcium and vitamin D, both of which play a vital role in the development and maintenance of healthy teeth and bones. A range of B vitamins are also found in milk, including thiamine, riboflavin, and vitamin B12.
While the majority of milk consumed in developed countries comes from cattle, milk is also produced on a commercial scale from sheep, goats, water buffalo, yaks, donkeys, camels, and reindeer. Milk is used to produce dairy products such as yogurt, butter, cream, and cheese. The type of milk used to produce the dairy products can significantly affect their taste and texture.
Commercially produced milk is pasteurized prior to bottling. The pasteurization process kills bacteria and harmful microorganisms that occur naturally in milk. The pasteurization process reduces the amount of thiamine, vitamin B12, and vitamin C available from milk.
Milk contains a sugar called lactose, which can trigger symptoms of lactose intolerance. These include diarrhea, flatulence, abdominal bloating and cramping, nausea, and vomiting. Individuals with lactose intolerance should avoid consuming milk produced from animal sources. Possible alternatives for milk from animal sources are soy milk or rice milk, which do not contain lactose.
Individuals who experience lactose intolerance when consuming milk should carry out a patch test before using products containing milk.