“It is through them that the human child acquires size and shape!” – the milk advertising from 1950 did not skimp on superlatives and praised the “white gold” to the skies as, among other things, an essential source of calcium for strong bones.
That was over 70 years ago and the tone has changed drastically. Cow’s milk is no longer just praised – it is confronted with increasingly critical voices. Health bloggers and doctors accuse cow’s milk of causing illness. A “white poison” that promotes, if not causes, severe suffering.
There are milk critics in this country too. For example, Renato Pichler, President of the interest group for vegan and vegetarian people in Switzerland SwissVeg, advises against consuming cow’s milk: “The disadvantages of milk are so serious on so many levels that I would warn against its consumption.”
On the other hand, milk is recommended as part of a balanced diet in Switzerland. The Swiss federal food pyramid recommends three portions of milk a day.
The contradictory statements surrounding milk raise the question: Is cow’s milk friend or enemy? Does it make us strong or sick? And why do we even drink the breast milk of another species?
Why do people drink cow’s milk?
The human body is originally programmed to use milk only during infancy. But when people settled in Europe around 6,000 years ago, a genetic change occurred.
Milk – a nutrient bomb
Cow’s milk consists of 87 percent water. Nevertheless, hardly any other food offers such a high nutrient density.
In addition to valuable proteins, fats and carbohydrates, cow’s milk also contains minerals such as calcium, zinc and iodine and vitamins such as A, B2, B12, C, D and E. These are important for metabolic processes and the immune system.
Thanks to this mutation, some people developed the ability to produce the enzyme lactase throughout their lives. Lactase is necessary for the digestion of milk sugar (lactose). These people were therefore able to easily digest milk and dairy products throughout infancy, giving them an evolutionary advantage.
The enzyme lactase plays a crucial role in the digestion of cow’s milk. It breaks down lactose in the small intestine. Lactase production is usually guaranteed in the first few years of life.
But starting around the age of three, the body reduces or, in some cases, stops producing this enzyme. In such cases, the milk sugar, lactose, enters the large intestine undigested, which can result in a number of unpleasant symptoms such as flatulence, stomach cramps and diarrhea.
Lactose intolerance or milk sugar intolerance can be more or less pronounced.
This genetic trait was passed on to subsequent generations. This mutation has also become established in some regions of Africa. However, the majority (65 percent) of humanity in adulthood is lactose intolerant.
Healthy bones only thanks to milk?
The healthy image of milk remained untouched for a long time. The “white gold” was primarily praised as a source of calcium for healthy bones.
The milk owes its good reputation not least to the skilful marketing of the dairy industry. Even Swissmilk now states on its own website that “cow’s milk is not a medicine” and does not protect against osteoporosis in old age. The idea that milk is particularly good for bones still persists today.
However, nutritionists like David Fäh from the Bern University of Applied Sciences have clear objections to the old advertising promises. He says: “There is a lack of scientifically sound basis for this.”
Adequate calcium intake is important for bone health, but it should not be overestimated. Healthy bones also require a fundamentally balanced diet, regular exercise and a healthy body weight.
Although cow’s milk is a good source of calcium, plant sources such as nuts, seeds or legumes also provide calcium. For example, Asian peoples who traditionally do not consume cow’s milk sometimes even have lower rates of osteoporosis and bone fractures than Western peoples.
In this country, where milk consumption is higher, the rates of osteoporosis are higher. Conversely, does this mean that cow’s milk could be harmful?
Three popular milk alternatives under the microscope
Numerous milk alternatives now fill supermarket shelves. When purchasing and consuming, you should pay attention to whether the product contains artificial additives and how heavily processed the product is. The most popular alternatives include:
- Soy drink is basically soy and water. However, purchased products can contain all sorts of additives. These include sugar, salt, potassium phosphate and calcium carbonate, and vitamins are often added. Soy milk contains a relatively high amount of proteins (8 g per glass), which is comparable to cow’s milk. Cow’s milk contains more carbohydrates and fat and is therefore significantly higher in calories than soy milk.
- Oat milk consists of oats and water. The same applies as for soy milk, purchased versions can contain all sorts of additives, it’s worth taking a look at the label. Oat milk has a relatively high amount of sugar in it, but still has fewer calories compared to cow’s milk. One advantage is that oat milk is high in fiber, which is good for digestion.
- Almond milk consists of almonds and water. Purchased versions are often sweetened. If you don’t want that, you should pay attention to this when purchasing. Unsweetened versions are low in calories and have little protein. If you want to lose weight, almond milk can be a good option.
Tip: Do milk alternatives flake in coffee? This could be due to the temperature difference or the tannins in the coffee. A type of coffee with less acid or slowly warming the milk will help.
More on the topic in the “Puls Check” episode “Milk myths debunked” on PLAY SRF.
Milk is poison?
A clear milk critic is family doctor Renato Werndli from Eichberg. In his practice, he goes so far as to advise patients not to consume milk because numerous scientific studies that he has collected on the subject speak against it.
His accusations against cow’s milk are serious: diabetes, cardiovascular disease, acne, cancer. Werndli considers the growth hormones in milk to be particularly problematic. Like human breast milk, cow’s milk contains the growth hormone IGF-1. This plays a role in the process of cell growth.
Dairy critics like Werndli say the intake of IGF-1 from cow’s milk could stimulate the growth of cancer cells. An accusation that Felix Beuschlein, endocrinologist at Zurich University Hospital, cannot understand.
Beuschlein explains that the IGF-1 from cow’s milk is broken down in the stomach so that it cannot enter the bloodstream. “And if you imagine that an IGF-1 molecule could get into the bloodstream, that’s a drop in Lake Constance. “It doesn’t matter,” the expert is convinced.
Family doctor Renato Werndli emphatically points to the research that fuels his doubts about milk. But milk advocates also argue based on the scientific data. Barbara Walther from Agroscope emphasizes that the food pyramid is based on the latest scientific results.
You can always find one or more studies that confirm what you want to argue. And the other side finds at least as many.
The milk debate shows that there is scope for interpreting the study situation. Nutritionist David Fäh says: “You can always find one or more studies that confirm what you want to say. And the other side finds at least as many.”
This is because nutritional research has not yet managed to come up with a design that allows clear statements to be made. The evidence in nutritional science is usually only of limited significance because human nutrition is complex and individual.
Many of the studies are based on observations and questionnaires filled out by test subjects about their own eating behavior. In most cases, it is only years later that it is evaluated which illnesses the test subjects have suffered from in the meantime. This statistical connection says nothing about the exact causes of the disease. Because if two factors are related, it does not automatically mean that one causes the other.
So what can you stick to? Felix Beuschlein gives some advice: “Whether for or against milk: It is always a good reflex to question where the information comes from. A critical discussion is important.”
The contradictory results of nutritional science do not make this task any easier.
“Discussions about nutrition are almost always emotional”
Three questions for Prof. Felix Beuschlein, clinical director at the Clinic for Endocrinology, Diabetology and Clinical Nutrition at the University Hospital Zurich.
SRF Wissen: Let’s get straight to the point: Is milk healthy or not?
Felix Beuschlein: There are patients for whom milk is simply unhealthy because they have lactose intolerance or simply struggle with their quality of life when they drink milk. There are others for whom it doesn’t matter. There are situations in which milk is part of a balanced diet and others where milk is not harmful to health. In short: “Unhealthy” or “healthy” are relative terms that are different for everyone.
Is the discussion about the healthiness of milk justified?
Discussions about nutrition are almost always emotional. There is hardly anyone who looks at this completely neutrally. In a sense, we all see ourselves as experts because we all eat and are confronted with it every day.
You always find anecdotal evidence, but it is not evidence. My attitude as a doctor and scientist is that I want to know more. And because the level of evidence is relatively low, it is difficult to make clear recommendations. You shouldn’t make blanket statements either.
How useful is it to examine a single food like milk?
This generally doesn’t make sense. We humans are omnivores and our food supply is correspondingly huge. If we’re smart, we’ll pick out a little bit of everything because it reduces the likelihood of having any deficiencies. Conversely, this also means that a single food probably only makes a small contribution to health.