What is milk ????????
Answers
Explanation:
Milk is essentially an emulsion of fat and protein in water, along with dissolved sugar (carbohydrate), minerals, and vitamins. These constituents are present in the milk of all mammals, though their proportions differ from one species to another and within species.
Milk plays a crucial role in the life of all mammals, right from birth. But some say that drinking another mammal’s milk is unnecessary, unnatural, even unhealthy.
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s the only animal to drink the milk of another species, humans have an unusual relationship with the white stuff. Most other animals are weaned off milk in infancy, once we start to need more complex foods. So why do humans keep drinking it?
People living in parts of the world where cows were domesticated – starting in south-west Asia and spreading into Europe – only evolved to digest lactose around 10,000 years ago. As a result, around 30% of the world’s population continue to produce lactase, the enzyme required to be able to digest lactose, into adulthood. The rest cut back their production after the weaning phase of infancy.
Most people, then, become lactose intolerant, making milk-drinking Europeans, along with some African, Middle Eastern and Southern Asian populations, the exception rather than the rule. Among people of European descent in the US, only around 9% are lactose intolerant. Even those who can digest it might wish to reduce their milk intake because of other concerns, such as our health and the environmental costs of animal agriculture, which has been driving the growth of dairy-free alternatives to cow’s milk. (Read more about which humans evolved to drink milk, and why).
But are there any health benefits to ditching cow’s milk for an alternative drink, or does cow’s milk provide us with vital nutrients we can’t get elsewhere? And does milk actually aggravate most people’s lactose intolerance?
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Cow’s milk is a good source of protein and calcium, as well as nutrients including vitamin B12 and iodine. It also contains magnesium, which is important for bone development and muscle function, and whey and casein, which have been found to play a role in lowering blood pressure.
The UK’s National Health Service recommends children between the age of one and three consume 350 milligrams of calcium a day, which just over half a pint of milk would provide, for healthy bone development. But when it comes to adults, research as to whether cow’s milk helps to keep our bones healthy is conflicting.
It's recommended that small children consume 350 milligrams of calcium a day, which can be provided by just over half a pint of milk (Credit: Getty Images)
While calcium is required for healthy bones, the evidence that consuming a calcium-rich diet will prevent bone fractures is unclear. A number of studies have found no significant decrease in fracture risk from drinking milk, while some research suggests that milk could actually contribute to fracture risk.
One study in Sweden found that women who drank more than 200 millilitres of milk daily – less than one glass – had a higher risk of fractures. However, the study was observational, so the researchers cautioned against hyperbolic interpretations of their findings. It could be that people who are prone to fractures tend to drink more milk, warns the study’s author.
But calcium is crucial during our adolescence for the development of bone strength, says Ian Givens, an expert in food chain nutrition at the University of Reading.