While infants rely on milk, children and adults can access many other foods. Yet for many people, milk is part of their daily diet - starting with the breakfast cereal or the latte in the morning. But the health significance of milk is controversial. We examine the question of whether milk now promotes or harms our health.
The calcium supplier milk
The water content of milk can be compared with that of many fruits and vegetables. However, each portion consumes comparatively more vital nutrients - experts are talking about a higher nutrient density.
The best known is the high content of calcium in the milk. A half-liter covers the daily calcium needs of a primary school child to about 70 percent, of adolescents and adults to 50 to 60 percent.
Calcium plays an important role in bone formation. However, the mineral does not necessarily protect against increased bone fragility in old age, because the disease can have several causes. However, the high calcium content and the favorable calcium-phosphate ratio at every age have a beneficial effect on bone health.
More nutrients from milk
Other minerals such as zinc and magnesium are also abundant in milk. Vitamins are especially vitamins A and D and various B vitamins.
Milk also contains proteins - the so-called milk protein. This has a high biological value. This means that the nutritional proteins of milk can be efficiently converted into the body's own proteins. The most basic criterion for the biological value of food is the composition of the amino acids. The more essential amino acids a food contains, the more valuable its proteins will be.
Since the amino acids of different foods can complement each other, the biological value can be increased by a clever combination of foods. For example, the combination of milk and wheat flour has a high biological value.
Types of dairy products
Milk is available in many different varieties, as it can be further processed in different ways. For example, milk can be heated, pasteurized, homogenized or its fat content reduced:
- Raw milk: Raw milk is untreated milk from livestock that has not been heated above 40 degrees Celsius. In Germany, raw milk may only be sold directly from the farm under strict hygienic conditions. To minimize the risk of infection, raw milk should always be boiled before consumption.
- Fresh Milk / Pasteurized Milk: Raw milk is made into fresh milk by pasteurizing. Here, the milk is heated for 15 to 30 seconds to 72 to 75 degrees Celsius. This reduces the germ count and increases the durability. Thanks to gentle pasteurization, fresh milk hardly ever loses valuable ingredients.
- ESL milk: This milk has replaced fresh milk in almost all supermarket shelves and hardly differs from it. ESL-milk (English: extended shelf life) is either shorter, but more heated than fresh milk, or it is microfiltered.
- UHT milk: The milk is heated to 135 to 150 degrees Celsius for a few seconds, sterilizing it. Then the milk is homogenized, that is, the milk fat is distributed evenly, so that the milk is not so easily creamed and easier to digest. Disadvantage of this treatment method is that many of the valuable ingredients are lost. However, the milk is stable for several months.
- Condensed milk: The milk is heated to 85 to 100 degrees Celsius for 10 to 25 minutes to kill germs. Thereafter, it is thickened under reduced pressure, which removes about 60 percent of the water. Finally, it is still homogenized.
Fat content of milk
Whole milk, 1.5% milk or the very lean version - in front of the milk shelf you are spoiled for choice. In principle, milk fat is well tolerated, as many so-called medium-chain fatty acids are in it. In addition, there are many bioactive fatty acids whose levels are influenced by the food of the animals. Organic cows, which often eat more fresh grass, provide about three times more conjugated linoleic acid (CLA) than conventional milk, according to research.
As a rule, you can choose between the following fat levels of milk in the supermarket:
- Whole milk contains at least 3.5 percent fat.
- The fat content of low-fat milk is between 1.5 and 1.8 percent fat.
- Skimmed milk or skimmed milk contains only up to 0.5 percent fat.
Depending on their fat content, the lower-fat milk has fewer calories, which is often important for the purchase decision. 64 calories per 100 milliliters of whole milk are here compared to 35 calories for skimmed milk. Lean people can safely access to whole milk; Of course, the fat-reduced version is more suitable for people who want to lose weight. Here, however, the fat-soluble vitamins A and D are reduced.
Is organic milk really healthier?
The organic milk in the supermarket costs significantly more than the conventional milk. Many conclude that not only the cows lead a more species-appropriate life, but that organic milk is also healthier than normal milk. But, is this really the truth?
The ingredients of the two types of milk differ only slightly. A large-scale meta-analysis of Newcastle University 1 has shown that organic milk has a higher proportion of omega-3 fatty acids due to the higher percentage of grass in the feed of organic dairy cows: half a liter of organic milk contains 16 percent of the recommended daily amount omega-3 fatty acids, compared to just 11 percent in conventional milk. Also, organic milk contains slightly more iron and vitamin E. Conventional milk contains about 74 percent more iodine, as it enriches the cows' concentrated feed.
After all, there is not much difference in quality between organic milk and normal milk. Although the milk varieties differ slightly in their components, it is no longer possible to detect residues of pesticides in normal milk than in organic milk. The consumption of organic milk has only a small demonstrable health benefit. Nevertheless, one thing speaks clearly for the purchase of organic milk: The animal welfare attitude, which is then worth the price difference.
Beware of sweets "with the extra portion of milk"
Many foods that - especially children - should deliver "an extra portion of milk" are in most cases not recommended. Because no matter if nougat spread, chocolate bars or other confectionery with milk filling - to the benefits of milk is always a high proportion of fat or sugar added.
Although such foods do not have to be wholly discarded from the diet, they should not be understood as a "healthy meal".
cow's milk allergy
People with a milk allergy react to certain proteins in cow's milk with discomfort. The reason for this is that their immune system - as with all allergies - classifies an actually harmless substance as a foreign body, fights it and overreacts it.
The symptoms may appear immediately after the consumption of milk or delayed. Typical symptoms include tingling in the mouth, itching and swelling of the mucous membranes and the skin, shortness of breath and gastrointestinal complaints.
An allergy to cow's milk often occurs during babyhood - about two to three percent of all infants are affected. The milk allergy usually develops in the first months of life and often after the baby's weaning. However, 90 percent of affected children develop tolerance to milk proteins until school age.
Those who have a permanent allergy to cow's milk protein may be able to switch to goat and sheep's milk, which are available for example in the organic trade.
Eczema and cow's milk
Cow's milk allergy can also trigger or exacerbate eczema. However, this is not always the case, it can also cause other allergenic foods such as wheat, soy, fish, nuts or eggs. Therefore, it should be determined which allergens affect the skin disease and then the diet is changed accordingly.
Lactose intolerance (lactose intolerance)
To differentiate from the milk allergy despite similar symptoms is the lactose intolerance. Here, the person tolerated no lactose (lactose), another ingredient of the milk. To absorb lactose in the intestine, the human must first split it. The enzyme required for this purpose, lactase, is no longer produced in sufficient quantities by many adults, which can lead, inter alia, to bloating and diarrhea when consuming dairy products.
In Germany, such lactose intolerance exists in about 15 percent of adults. Milk is almost only tolerated by children in Asian countries, which is why dairy products are rarely found on menus from the Far East.
However, lactose intolerance can vary. Some still tolerate the milk in coffee. Even matured cheese is usually well tolerated, since it hardly contains any lactose.
Incidentally, the fact that some adult humans can produce the enzyme needed for the digestion of milk lactase, is due to a gene mutation of about 7, 500 years ago.
Alternatives to cow's milk and lactose-containing milk
If you have cow's milk allergy or lactose intolerance, you can easily switch to alternatives to milk. In these, the components of the milk are replaced by vegetable proteins and fats. Accordingly, such products are free of animal protein, lactose and cholesterol - and at the same time vegan.
Cow's milk alternatives include:
- soy milk
- Grain milk such as oat or rice milk
- Almond milk
In addition, for people with lactose intolerance, there are numerous lactose-free products in the supermarkets, which are also an alternative.
Interactions with drugs
Even people without allergy and intolerance should avoid milk in some cases. For example, if you take certain antibiotics, iron supplements or biphosphonates for osteoporosis treatment. Here is the possibility that milk or dairy products limit the effectiveness of the funds.
The reason is the calcium contained in the milk. This can form in the stomach with certain - not with all - drugs sparingly soluble compounds. As a result, the drugs are less absorbed by the body and therefore can not develop their full effect.
It is recommended to drink milk only every two hours to take the medication. Relevant information can also be found on the package leaflets, which should be observed in any case.
Milk: healthy or unhealthy?
When it comes to the question of whether milk is beneficial or harmful to health, the minds and opinions of science are divided.
Milk critics say eating milk raises the risk of cardiovascular disease, diabetes and osteoporosis. The reason they cite is the saturated fat in the milk, which would increase cholesterol and cause cardiovascular disease.
It is clear that the regular consumption of milk can not prevent osteoporosis, because in addition to a calcium deficiency, other factors are involved in the development of the disease. However, studies have now found that milk even favors the risk of osteoporosis. However, the Max Rubner Institute does not see any connection between milk consumption and osteoporosis.
In a nutritional evaluation of milk, dairy products and their ingredients 4, the Institute continues to write that increased consumption of milk and dairy products is not associated with an increased risk of cardiovascular disease, hypertension and stroke. On the contrary - milk even lower the risk for it. However, these statements only apply to reduced-fat milk and dairy products.
Milk, dairy products and the risk of cancer
It is highly likely that men who consume more than 1.2 liters of milk or more than 100 grams of hard cheese such as parmesan a day are at an increased risk for prostate cancer. 5, 6, 7
Things are different for women: a meta-analysis 8 provided indications that dairy products can significantly reduce breast cancer risk. On the other hand, there are also studies 9 that suggest that milk-containing lactose in women could increase the risk of ovarian cancer. This is certainly not confirmed.
Furthermore, according to the German Society of Nutrition (DGE) and World Cancer Research Fund International (WCRF), milk and dairy products reduce the risk of colon cancer. Studies suggest that this beneficial effect occurs every 200 milliliters of milk daily and is due to calcium.
How much milk is healthy?
According to the DGE, 200 to 250 grams of milk and yogurt per day are recommended. Add to that 50 to 60 grams of cheese, that is about two to three slices. Low-fat products are to be preferred, so that the daily fat intake can be kept low.
However, the average daily consumption of milk and dairy products in Germany is only 190 grams per day. Also, the recommendation of the DGE - as well as the scientific situation on milk in general - is controversial.
Sources and studies
- Newcastle University (2016). Study finds clear differences between organic and non-organic products.
- Michaëlsson, K. et al. (2014). Milk intake and risk of mortality and fractures in women and men: cohort studies.
- Warensjö, E. et al. (2011). Dietary calcium intake and risk of fracture and osteoporosis: prospective longitudinal cohort study.
- Max Rubner Institute (2014). Nutritional evaluation of milk and milk products and
- Qin, LQ et al. (2007). Milk consumption is a risk factor for prostate cancer in western countries: evidence from cohort studies.
- Qin, LQ, et al. (2004). Milk consumption is a risk factor for prostate cancer: meta-analysis of case-control studies.
- Lu, W. et al. (2016). Dairy products intake and cancer mortality risk: a meta-analysis of 11 population-based cohort studies.
- Dong, JY et al. (2011). Dairy consumption and risk of breast cancer: a meta-analysis of prospective cohort studies.
- Larsson, SC et al. (2006). Milk, milk products and lactose intake and ovarian cancer risk: A meta-analysis of epidemiological studies.