Humans have an unusual relationship with milk. We still drink milk even after we start eating more complex foods. People who are living in parts of the world where cows are domesticated, like in south-west Asia and Europe, evolved to digest lactose. As a result, 30% of the world's population continue to produce lactase, which is the enzyme needed to be able to digest lactose into adulthood.
Most people, then, become lactose intolerant, making milk-drinking Africans, Europeans, South Asian, and Middle Eastern populations the exception rather than the rule. Among people of European descent in America, only 9% are lactose intolerant. Even those who can digest it might wish to reduce their milk intake because of other concerns, like health and environmental costs of animal agriculture, which has been driving the growth of dairy-free alternatives to cow's milk.
But are there any health benefits to drinking alternative drink instead of cow's milk, or does cow's milk provide us with nutrients that we can't get elsewhere?
Benefits of cow's milk
Cow's milk is a great source of calcium and protein, as well as nutrients, including iodine and vitamin B12. It also contains magnesium, which is very important for bone development and muscle function, and casein and whey, 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 to drink 350 milligrams of calcium every day, which is over half a pint of milk would provide for healthy bone development. When it comes to adults, the research as to whether cow's milk is beneficial to healthy bones is conflicting.
Calcium is needed for healthy bones, but the evidence that consuming a calcium-rich diet will prevent bone fractures is still unclear, A number of studies have found no decrease in fracture risk from drinking cow's milk, while some studies suggest that milk could actually contribute to fracture risk.
Ian Givens, an expert in food chain nutrition at the University of Reading, said that calcium is needed during our adolescence for the development of bone strength. He also said that if you do not get bone development correct in your teenage years, you will run a higher risk of bone weakness in later life, particularly for women after menopause, who lose the benefits of oestrogen.
Health concerns
A concern around cow's milk in the past few years is the hormones we consume in drinking in. Cows are milked when they are pregnant when their oestrogen levels increase 20-fold. Although one study linked these oestrogen levels to breast, ovarian, and uterine cancers, Laura Hernandez, who studies lactation biology at the University of Wisconsin, says that ingesting hormones through cow's milk is nothing that to worry about. It is because human milk has hormones, too, and it is a part of being a mammal.
Studies have also found a connection between milk intake and heart disease due to the saturated fat content in milk. But whole milk only contains around 3.5% fat, semi-skimmed around 1.5% and skimmed milk 0.3%, while unsweetened soy, hemp, almond, coconut, rice, and oat drinks have lower levels of fat than whole milk.
The rising demand for cow's milk alternative
While there is a lot of research looking at the effects of cow's milk on our health, there is less research for dairy-free options. There is a rising demand for alternatives made with almonds, soy, hazelnuts, cashews, macadamia nuts, coconuts, flax, rice, hemp, or oats. The main ingredient is processed and diluted with water and other ingredients, including stabilizers like locust bean gum and gellan gum.
The best replacement for cow's milk in terms of protein is soya milk, as it is the only one with comparable protein content. But the proteins in alternative drinks may not be true protein, according to Givens. He also said that it may be of a substantially lower quality protein than milk, which is an important point for children and the elderly in particular, who have an absolute requirement for high-quality protein for bone development.
