Kirill Yurovskiy: Benefits and harms of milk for the human body
Some experts say that this product can cause cancer. And others are sure that it is the perfect food! So should adults drink milk? And for children? Can milk be dangerous? We have tried to find the answers to the most popular questions about milk.
Milk is man’s oldest food, has it been drunk since the dawn of time?
Well, no. Since time immemorial, babies have been fed on their mothers’ milk. And the milk of animals entered the diet of our ancestors much later than meat and plants.
Moreover, ancient people were not able to digest milk. This became clear when scientists deciphered the genome of a man who lived 5,300 years ago and whose remains were found in the Alps. So the gene responsible for the digestion of milk in our prehistoric ancestor was turned off. And in general, at the dawn of mankind, this gene was turned on only in infants who were breastfed by their mothers.
Mankind had to learn to drink milk in order to survive. When the migration from Africa began 2000 years ago, the nomads, who were breeding animals for meat and skins, needed a new source of nutrition – and animal milk was it. History is silent about how many people died in this process, including because someone could not eat cow’s or mare’s milk. So not everyone survived, but only those whose digestive systems began to slowly evolve. How to choose healthy milk – link.
Why can’t adults digest milk?
In 2009, a young Australian motorcycle racer, Casey Stoner, suddenly fell off the race course, he suddenly felt ill. And then he had to leave the sport. It turned out that the athlete has an acute intolerance to milk sugar – lactose.
Lactose normally breaks down into glucose and galactose, and this is how our body absorbs it. To break down lactose, we need an enzyme called lactase. In the 1970s, Soviet scientists discovered that there was a gene variant that stopped synthesizing this enzyme. At first, scientists thought it was abnormal. And then they discovered that initially all adults don’t digest milk sugar, and just that is the norm. A DNA mutation is the reason why adults can drink milk and get nothing for it.
In ancient Rome, milk was not used as a food, but as a medicine (e.g. as a laxative). If you don’t have this enzyme, you are unable to break down lactose, and the milk you drink stays in your intestines, where it causes bloating, bloating, and diarrhea.
How many adults can’t drink milk?
Now the ancestors of the man who first could digest milk have spread across northwestern Europe. Some of them live, for example, in Italy, in Russia.
But not all peoples got this lucky DNA mutation. The Chinese, for example, drink soy milk (from soybeans) or rice milk (from rice) instead of cow’s milk. By the way, even black milk (from black soybeans) is sold in China. Blacks and Hispanics have a particularly hard time digesting milk. On average, on our planet, populated by more than 4 billion people, about 6 people out of 10 cannot tolerate milk.
However, even in our country, with its traditional culture of consuming milk and milk products, not everyone drinks it. According to some data, one-third to one-half of all adults in Russia cannot digest milk.
Why do people need milk at all?
Today, scientists are going to great lengths to make it easier for people to drink milk. They have invented tablets with lactase enzyme, and even lactose-free milk is produced. Nutritionists suggest replacing milk with kefir, where lactic acid bacteria eat the milk sugar. But what is the purpose of all this? To get calcium from milk, so necessary for our bones.
Is it true that only natural milk is a good source of calcium?
It is believed that calcium is best absorbed from dairy products. Three glasses of milk (in 250 ml – 315 mg) contain the daily norm of calcium for an adult (800-1100 mg). But, of course, there are few adults who like to drink this much milk every day. So it is possible (and effective) to eat dairy products with high calcium content – cottage cheese, cheese and yogurt.
What about those who are intolerant to dairy products?
Milk is not the only food rich in calcium. Calcium is also abundant in broccoli or almonds, for example. But it needs the right conditions to assimilate it, such as vitamin D, which, in turn, is synthesized under the influence of ultraviolet light. So in hot, sunny climates, it’s easier to do without milk – warmed up in the sun (got vitamin D), ate some broccoli (got calcium), and everything is normal.
Residents of the Far North, where there is little sunshine, and milk is not absorbed, have another source of vitamin D and calcium. They eat the liver and fat of sea animals and fish. Vitamin D is produced there because the animals eat algae. Deer meat and fat are also good sources of vitamin D.
But it’s not so simple here either. To get his rate of calcium and vitamin D, the Nenets have to eat a day 2 kg of reindeer meat and fish, plus 200 grams of fat (actually a pack of butter a day!).
In Soviet times, the peculiarities of the metabolism of the inhabitants of the Far North were not known. And of course, when the children of reindeer herders ended up in boarding schools on the great land, they received the usual food. As a result, after drinking milk, these children had a disorder, which was unsuccessfully treated with antibiotics.
Can milk be dangerous?
We have already talked about acute intolerance to milk sugar – lactose. But there are also elements in milk itself that can be dangerous. Milk is 77% water, but it also contains fats, carbohydrates, and proteins. Casein, globulin, and albumin-these three types of proteins make milk very beneficial, but they also make it a strong allergen.
An allergy to milk can be acute, in which case a person gets Quincke’s edema after drinking a glass of milk. Or you can suffer from asthma all your life and not realize that it’s an allergy to cheese, yogurt, or ice cream. Many people don’t even know that they are allergic to milk and products that contain it.
The benefits of milk for adults
If you can digest it and you are not allergic to it, yes. Many years of research by various domestic and foreign institutes of dietetics provide reliable scientific evidence that people who consume enough milk and who prefer butter to margarines have a stronger immune system. Dairy products saturate the body with vitamins and micronutrients, and, of course, they are a great source of calcium. And this is especially important for adults – because osteoporosis is just around the corner.
Milk for children
This is for parents to decide. If a child is found to be allergic to milk, it is clear that they should look for another source of calcium.
For everyone else, here are just two facts.
Fact one. Osteoporosis destroys the bone system of one in four women after age 60. And the resistance to osteoporosis is laid at the age of 8-9 years. It was found that in girls, the maximum ability to absorb calcium is retained until the age of 10. After this age it begins to decrease.
Fact number two. The Japanese and Chinese, as we have already found out, traditionally do not drink milk and do not absorb it well. However, after the introduction of a program in which every child in a Japanese school received a mandatory glass of milk, we found that the nation has grown – on average, by 8-10 cm.
So your child’s health is in your hands, that is, in the glass of milk.