Healthy milk and bad sausage? Nutrition myths put to the test
Does milk really make you strong? Is meat good for my child? Should sugar be avoided at all costs? Old wisdom about what is healthy and what is not, which is deeply rooted in our society, has begun to falter. This sometimes leaves us perplexed: What are we still allowed to eat? And above all, what should we feed our children? As an author who often writes about nutrition, over time I came to the realisation that the golden mean is the right one, even when it comes to food.
But what exactly does that mean? And is it even true? I set out in search of clues - and put seven myths to the test of science.
1. «Milk makes you strong»
Hardly any other food plays such a central role in children's nutrition as milk. «Milk makes you strong» is firmly anchored in people's minds. Especially when it comes to the nutrition of children and adolescents. Milk is considered an important source of calcium, which strengthens bones and teeth. The milk recommendations of the Swiss Society for Nutrition (SGE) vary according to the age of the child. According to this, ten to twelve-year-olds should consume three portions.
A portion is considered to be 2 decilitres of milk, 150 to 200 grams of yoghurt, quark or cottage cheese, 30 grams of semi-hard or hard cheese or 60 grams of soft cheese. This results in a daily amount of up to 460 grams.
Milk drinkers are getting bigger
«Such a high consumption of milk is often justified by the calcium supply. According to this, milk is supposed to strengthen bones and prevent fractures,» says Walter Willett, Professor of Nutritional Science and Epidemiology at the Harvard School of Public Health in Boston. «But there is no scientific evidence for this.»
The 72-year-old Willett is the most cited nutritionist and researches how nutrition and disease are linked. «The myth that children should consume lots of dairy products to strengthen their bones definitely doesn't seem to stand up to reality,» says Willett. «We now know that young people with a high dairy intake have a higher risk of bone fractures in adulthood.»
Ella Macher, 16, from Bäretswil ZH (top left) suffers from severe food allergies. Her parents Sandra and Andreas and brother Flynn, 12, have therefore turned their own diet upside down. Read here what this means for the family's everyday life.
One probable reason for this is that high milk consumption in childhood leads to longer bones - which are therefore more susceptible to fractures. The fact that milk drinkers grow taller is undisputed. However, taller does not necessarily mean healthier.
«People who are tall have an increased risk of certain types of cancer,» says Susannah Brown from the World Cancer Research Fund. «The risk factor is not height itself, but the growth process we go through into adulthood. » How tall a person becomes also depends on their diet in childhood and adolescence.
For example, a diet high in protein favours faster growth and a taller body size, and overweight children also tend to grow faster. In addition, puberty sets in earlier.
No more need for milk after breastfeeding
«Such developments are a direct or indirect consequence of our diet as a child,» says Brown. «Elevated levels of growth and sex hormones play a key role in this.» These hormones influence body size and sexual characteristics, but also the behaviour of our cells - and thus the risk of cancer.
What does this have to do with milk? «We know that a high consumption of dairy products increases the concentration of growth factors in the blood,» says nutritionist Walter Willett. The focus here is on the growth factor IGF-1, which accelerates cell division.
Research shows: Young people with high milk consumption have a higher risk of bone fractures.
An increased level of IGF-1 has been shown to be associated with an increased risk of certain types of cancer. According to Willett, it is not yet clear why people who consume a lot of dairy products have more of this messenger substance in their blood. However, growth hormones in cow's milk are suspected. Breast milk also contains growth hormones.
However, after the breastfeeding period, from around the age of three, humans no longer need milk: «Then rapid growth is no longer desirable, but is associated with health risks.»
Rising oestrogen levels in milk
Harvard researcher Ganmaa Davaasambuu also describes the sex hormones contained in cow's milk, especially oestrogens, as such. According to Davaasambuu, it is not milk per se that is problematic, but the product of ultra-modern dairy farming, which keeps cows pregnant and milks them almost continuously. «As pregnancy progresses,» says Davaasambuu, «the oestrogen level in the milk rises.»
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In addition to Western high-performance milk, the researcher also analysed raw milk from Mongolia: this had a concentration of female sex hormones that was up to 33 times lower. Cows in Mongolia are not artificially inseminated and are only milked in the first three months of pregnancy. «The milk we consume today has hardly anything to do with the milk our ancestors drank,» says Davaasambuu.
Milk is healthy - for malnourished children
«We lack many answers to the question of how the consumption of dairy products in childhood affects health,» says Willett. «Until more information is available, moderation is a good middle ground.»
Problematic: Milk as a product of a dairy industry that keeps cows pregnant and milks them almost continuously.
The researcher describes quantities of no more than two portions of dairy products a day, regardless of type, as moderate. «Milk contains important nutrients such as protein and calcium,» write researchers Willett and David Ludwig in the journal JAMA. Milk can offer health benefits to children affected by malnutrition. «However, for children who already enjoy a high-quality diet of green leafy fruits, vegetables, nuts and seeds, and good sources of protein, the benefits of milk may not outweigh any health risks.»
2. «Meat must be»
Nowadays, not eating meat hardly causes a stir. Wherever we dine, vegetarian options are commonplace. There is also little doubt that a meat-free diet does not necessarily lead to deficiency symptoms. However, we are not quite so relaxed when it comes to children. The question remains: do our offspring need meat to grow up healthy?
«Meat is a high-quality food, rich in protein, iron and other vital substances,» says Josef Laimbacher, Head of Paediatrics and Adolescent Medicine at the Children's Hospital of Eastern Switzerland and member of the Federal Commission on Nutrition.
Organic quality guarantees us a high degree of certainty that meat is not contaminated with antibiotics.
Josef Laimbacher, paediatrician
In order to be able to propagate meat consumption, however, one important prerequisite must be met. For Laimbacher, this is organic quality: «It guarantees us a high degree of certainty that the meat is not contaminated with antibiotics or residues from contaminated animal feed.» If these conditions are met, meat is a valuable source of essential amino acids for children's nutrition.
These are protein building blocks that are involved in muscle building and the production of enzymes, hormones and antibodies in the body, among other things.
It also works without
Is it possible without? «Basically yes,» says Laimbacher. However, feeding a child a vegetarian diet doesn't just mean removing meat products from the diet, but replacing them with a balanced mixed diet. Dairy products, eggs, pulses, cereals and nuts are good sources of protein and also provide essential amino acids. «Protein deficiency is no longer an issue in our latitudes,» says Laimbacher.
The increasing popularity of a meat-free diet does nothing to change this. Vegetarian children have to cover their vitamin B12 requirements, which is essential for blood formation and the functioning of the nervous system, with dairy products and eggs. «A balanced diet that doesn't include meat but does include other animal products», says Laimbacher, «covers the nutritional needs of the growing child well.»
3. «Vegans are raven parents»
But what about the vegan diet, which excludes all foods of animal origin? We read in the media about mothers and fathers who fed their children dried fruit until they were ready for hospitalisation, about a baby who starved to death on a plant-based diet because his parents didn't offer him any infant milk after breastfeeding didn't work.
Children have also had to be treated at the Eastern Switzerland Children's Hospital where a vegan diet had led to severe developmental deficits: «Most of them were babies and toddlers with irreversible brain damage caused by a lack of vitamin B12 in the mother during pregnancy and breastfeeding.»
However, Laimbacher emphasises that these patients are isolated cases, of which he has not seen any more in recent years: «This is probably due to more intensive education.» The image of vegan raven parents circulated by the media is exaggerated.
Seitan and beans have more protein than meat
A purely plant-based diet, says Laimbacher, certainly offers certain health benefits, especially with regard to diseases of civilisation such as obesity. Nevertheless, the paediatrician does not recommend feeding children this diet: "Because a vegan diet is simply not a recommendation suitable for the masses.
It requires a good level of expertise on the part of the parents and a willingness to invest more time in it." This includes advice from a qualified nutritionist and regular check-ups with the paediatrician - including laboratory tests.
Sandra and Tanja's patchwork family eats raw food. When Luca*, 12, David, 9, or 6-year-olds Mia and Anna celebrate their birthdays, even the cake is raw. Click here for the article.
Parents who opt for a plant-based diet must carefully compile their children's diet so that they get all the important nutrients in the right quantities. Nuts, seeds, pulses and products made from them, such as tofu, provide protein and calcium and, depending on the variety, also plant-based iron. Wholemeal cereals are also good sources of protein.
Some beans or seitan, a meat substitute made from wheat protein, even outperform meat in terms of protein content. Green leafy vegetables and calcium-rich mineral water also play an important role in the calcium supply.
Vegans can obtain iron from cereal products, nuts and seeds, dried fruit, spinach or rocket. Certain acids such as vitamin C help our body to better absorb iron from plants. The bioavailability of nutrients - what the human body can effectively absorb from them - is lower in plant sources than in animal sources. «That's why vegan children should eat around a quarter more plant products every day than their traditionally-fed peers,» says Laimbacher.
B12 from tablets
Vitamin B12, which is essential for our health, is found almost exclusively in animal products. Vegans cannot avoid taking it in artificial form, for example in tablet form. «These supplements are essential to stay healthy,» says Laimbacher. «Well-informed parents know that.»
Depending on the supply situation, other supplements may also be necessary. «I'm not demonising veganism,» says paediatrician Laimbacher. «Specialists should take a stand on it, and in a differentiated way. After all, the aim is to provide a growing group of parents who feed their children this way with the necessary information.»
4. «Sausages are evil»
From rotten meat to antibiotic residues - meat has often been in the negative headlines and many consumers are unsettled. The WHO also caused an uproar when it categorised processed meat as carcinogenic category 1 almost two years ago. According to the WHO, this puts sausage and co. on the same level as carcinogenic substances such as tobacco smoke, asbestos, plutonium or X-rays.
The WHO followed up its expert report with explanations for the average citizen. In it, it clarifies what is meant by hazard level 1: «This category applies when there is sufficient and convincing scientific evidence that the substance in question causes cancer in humans.»
Not a case for the Znünibox
Sausage, cold cuts, pâté, dried meat or tinned meat are often preserved with nitrite- or nitrate-containing curing salt. Our body converts these compounds into nitrosamines, which are considered highly carcinogenic. According to the WHO, the fact that processed meat ranks at the same risk level as cigarettes means that in both cases there is a clear statistical link between the risk factor and the occurrence of cancer - but not that sausages pose the same risk as cigarettes.
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According to the WHO, 34,000 cancer deaths worldwide every year - mainly colon cancer - are caused by processed meat. In the same period, one million people worldwide die of cancer as a result of smoking. Even before the WHO, researchers at the University of Zurich were investigating the link between the consumption of processed meat and the risk of cancer and cardiovascular disease.
Their conclusion: the critical limit is 40 grams. This amount is quickly reached, warns study co-author Sabine Rohrmann: «An average slice of ham or salami already weighs 20 to 30 grams.» What do these findings mean for parents? They shouldn't make us panic - but they should encourage moderation: We can still go out for a barbecue - but sausages and salami rolls have no place in a child's snack box.
5. «Red meat is unhealthy»
Red meat also has a tarnished reputation after the WHO placed it at risk level 2a at the same time as it warned against sausages. In concrete terms, this means that red meat is «probably carcinogenic» based on current data, but that other factors may play a role.
The focus is again on the risk of bowel cancer, which is determined by various factors. High levels of iron and harmful substances produced when frying, cooking and especially grilling and smoking meat are suspected.
According to the WHO, the risk of bowel cancer could increase by 18 per cent for every 100 grams of red meat consumed daily - if red meat actually proves to be carcinogenic. The WHO emphasises that the risk for individuals is small - but the findings are relevant for a society in which many people eat large quantities of meat.
Less is more
The Swiss Federal Commission for Nutrition has responded to the research and is generally in favour of reducing meat consumption, especially red and processed meat. The SGE recommends that adults should not eat meat more than two to three times a week and that children aged ten to twelve should eat meat no more than five times a week.
Youth physician Josef Laimbacher says that children are also well served with two to three portions of meat per week: «They don't need more.» He summarises: «Using meat correctly as a source of nutrients means, above all, keeping an eye on the quantity.»
6 «White meat is better»
A different picture presented itself to the researchers when they reconstructed the eating habits of over 44,000 women at the time of their adolescence using old questionnaires: young women who eat red meat more than once a day during puberty and adolescence have a 22 per cent higher risk of developing breast cancer.
Meatless happiness
- Ovo-lacto-vegetarians eat eggs and dairy products, but nothing made from the killed animal - so neither meat and fish nor animal fats and gelatine.
- Lacto-vegetarians eat dairy products, but no eggs. Ovo-vegetarians eat eggs, but no dairy products.
- Vegans avoid all foods of animal origin, from meat and dairy products to honey. Many also avoid animal products in textiles or cosmetics.
- Frutarians only eat fruit, vegetables, nuts and seeds that are harvested without damaging the plant they come from. This includes foods such as berries or beans that can be picked without destroying the plant. Carrots or cabbage, on the other hand, are taboo because the roots of the plants are torn out during harvesting.
Young people are particularly at risk from any harmful substances in their food, says nutritionist Walter Willett: «This is impressively demonstrated in relation to female adolescents and their later risk of breast cancer.» In the long-term study «Nurses' Health Study», Willett and his colleagues analysed the connection between diet and breast cancer, among other things.
For a long time, the focus had been on the eating habits of middle-aged and older women. According to Willett, corresponding studies have not suggested a link between breast cancer and the consumption of red meat.
According to the WHO, processed meat ranks at the same hazard level as cigarettes and asbestos.
The researchers derived an interesting prediction from the data: If young women replaced a daily portion of red meat with pulses, nuts, poultry or fish, their risk of breast cancer would fall by 14 per cent. Nevertheless, it remains to be seen whether white meat is actually healthier than red meat.
But there is also no epidemiological study that has established a link between white meat and cancer, says nutritionist Willett. Meanwhile, he advises parents to opt for chicken and fish as sources of animal protein.
7 «All organic, all good»
Food with the Bud label is no longer a niche product. Animal lovers favour organic because the label ensures better conditions for farm animals. Consumers also favour another argument: they buy organic products because they believe they offer health benefits. After all, organic farmers are not allowed to use synthetic pesticides or push animals with hormone-laden performance feed, to name just a few examples.
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So are organic products healthier than food from conventional agriculture? It makes little sense to talk about healthy products, says Urs Niggli, Director of the Research Institute of Organic Agriculture in Frick: «It's not individual foods that are decisive for our state of health: it's the way we eat.»
According to the agronomist, anyone who sticks to the usual recommendations and consumes little sugar, fat and meat and plenty of fruit and vegetables can consider their diet to be healthy. Organic products are therefore no guarantee of health, nor can they compensate for the effects of a poor diet. «But research shows,» says Niggli, «that they offer additional benefits.»
The icing on the cake
This includes a «massively higher» content of secondary plant substances, as Niggli says. Plants produce these bioactive substances to protect themselves from harmful environmental influences. Organic plants naturally produce more of them because they do not receive any protective help from pesticides. Most secondary plant substances act as so-called antioxidants, which research assumes help to prevent signs of ageing or certain diseases.
«One organic apple contains the antioxidants of one and a half conventional apples,» says Niggli. Organic meat and milk also score points with such extras. «Compared to products from conventional agriculture, they have a higher proportion of favourable fatty acids,» says Niggli.
Organic is not a must for a healthy diet
Organic cows feed on at least 90 per cent grass or hay. They form different molecules from the long-fibre roughage than from concentrated feed. Because organic farmers are prohibited from the preventative use of antibiotics or hormones, there is also no risk of such residues in meat and milk for the consumer. In the case of fruit and vegetables, products labelled organic also have up to four times lower levels of pesticide residues. The concentration of other environmental toxins is also significantly lower in organic produce.
However, Niggli emphasises that the legal limits for such substances in Switzerland are such that conventionally produced fruit and vegetables can be eaten without hesitation. Researchers at the ETH have made extrapolations with regard to environmental toxins in conventionally produced crops - and are of the opinion that the risk they pose shortens a human life by a week at most. «Organic is therefore not a must for a healthy diet,» says Urs Niggli, «but it is the icing on the cake, so to speak. That's why I don't want to do without it.»
Everything, but with moderation?
The question of what constitutes a healthy diet can never be answered conclusively. New findings are constantly being added; they are not always a blessing for the average consumer. We can hardly claim to keep track of everything. But it seems to me that it would make sense to at least approach the topic of nutrition without blinkers. This starts with not seeing science as patronising, but rather seeing it for what it is: an attempt to better understand the human body and what we feed it.
I've now spent weeks studying their findings - not to say struggling with them. It was tough reading. Nevertheless, it has motivated me personally to question generalisations, even if there are no answers. That's why I won't end here with the popular credo that we should eat everything, but with moderation. Rather, I believe that we should be allowed to rethink things here and there, even if it requires a little mental flexibility. After all, it's all about the sausage: our health and that of our children.
