«Intestinal diseases in children have increased»

Mr Posovszky, what physical complaints do children and adolescents come to you at the children's hospital with?

Those affected usually complain of vomiting, nausea, abdominal pain, diarrhoea or problems with bowel movements. The caring specialist staff refer the young patients to us in the gastroenterology department for further clarification and treatment. We have more comprehensive examination options than doctors in private practice, such as an endoscopy of the gastrointestinal tract.

And what do you see?

During the endoscopy, we can determine whether there is inflammation of the stomach lining, damage to the mucous membrane in the small intestine, as in the case of coeliac disease, or a chronic inflammatory oesophageal or intestinal disease. Crohn's disease can be accompanied by inflammation of the entire digestive tract, while ulcerative colitis involves chronic inflammation of the large intestine and eosinophilic oesophagitis involves chronic inflammation of the oesophagus.

We can also diagnose food-related diseases such as food allergies, lactose intolerance, gluten intolerance, i.e. coeliac disease, or infectious intestinal diseases without an endoscopy. Food-related diseases are much more common than chronic inflammatory diseases. Congenital diseases and malformations of the intestine, liver and pancreas are very rare. For this we require further diagnostics such as laboratory tests, genetic examinations and imaging procedures such as ultrasound or magnetic resonance imaging.

It is estimated that one in five people in Switzerland is lactose intolerant.

How many children are affected by these diseases throughout Switzerland?

The incidence in children is poorly studied. However, we do know, for example, that an estimated one in five people in Switzerland has lactose intolerance, one in twenty has a food allergy and one in a hundred has coeliac disease. Chronic inflammatory bowel diseases affect one in 350 people. Rare diseases are those that affect fewer than one in 5000 people. Despite considerable gastrointestinal complaints, we are often unable to diagnose any of these diseases in our young patients. In most cases, these are so-called functional bowel diseases.

What are they?

Children also suffer from functional disorders of the gastrointestinal tract. Irritable bowel syndrome is one of the best-known disorders in this area. Irritable bowel syndrome is characterised by recurring abdominal pain and diarrhoea or constipation. In other functional disorders, children complain of nausea, vomiting or stomach pain, and some complain exclusively of defecation disorders.

These disorders are not caused by food allergies, intolerances or inflammatory diseases. They are simply an expression of the fact that intestinal function is disturbed at various levels. For example, pain can be perceived much more quickly. This is why the term «disorder of the gut-brain axis» is increasingly being used instead of «functional bowel disease».

What does that have to do with?

We still know too little about the correlations to be able to make a well-founded statement. Possible causes discussed include disturbed intestinal movements, increased sensitivity to pain, a reduced mucosal barrier or altered intestinal immunity. Studies have shown that disorders of the gut-brain axis are often accompanied by a change in the gut microbiome. The microbiome refers to the entirety of all microorganisms, such as bacteria or viruses, that colonise our large intestine. They form our intestinal flora.

Is there a clinical picture that is increasing in children and adolescents?

Over the last 50 years, we have seen an increase in inflammatory bowel diseases and, in recent years, a significant increase in eosinophilic oesophagitis. Here, inflammatory cells migrate into the oesophagus and lead to a functional disorder. One of the manifestations of this is that those affected have problems swallowing and sometimes food gets stuck in their throat.

There are many causes of inflammatory diseases of the gastrointestinal tract.

At what age do those affected fall ill?

Here at the Children's Hospital, we look after infants and toddlers who vomit, have trouble eating or have difficulty swallowing, as well as adolescents who have food stuck in their oesophagus, for example. The symptoms are therefore very different across all age groups. During an endoscopy, we can see changes in the oesophagus.

Typical symptoms include longitudinal furrows, redness and inflammatory exudation on the mucous membrane. The so-called eosinophilic granulocytes are then found in the tissue samples. These are white blood cells that can be stained with eosin, an acidic dye, and give the disease its name. The number of cases is increasing so rapidly that we will soon have as many cases as Crohn's disease and ulcerative colitis.

And the disease is due to the diet?

It is probably an allergy-like chronic inflammation of the oesophagus. It is usually triggered by proteins in food. If certain foods are omitted from the diet of affected children, the inflammation disappears completely in some cases. In other children, unfortunately, we cannot identify any food as the cause. In these cases, treatment with medication is necessary. In principle, it can be said that the causes of all inflammatory diseases of the gastrointestinal tract depend on many factors.

That means?

That environmental influences, genetic factors and other triggers together lead to the disease. This is best analysed in the case of coeliac disease. Here, a genetic predisposition and other triggers, such as an intestinal infection, lead to an immune reaction to gluten, which comes from food. The immune reaction in turn causes destruction of the intestinal mucosa.

In inflammatory bowel diseases, there is therefore an interaction between genetic predisposition and environmental influences such as infections, hygienic conditions and diet.

That is correct. There are obviously factors that have a protective effect and there are factors that have a negative effect, such as certain foods that tend to promote an inflammatory environment.

Highly processed foods have a negative impact on our bodies.

So what can parents do to prevent their child from developing such a condition?

These diseases cannot be prevented. Many of the influencing factors cannot be changed. However, a healthy lifestyle can protect the body from unhealthy food, harmful environmental influences or stress.

Which type of diet is unhealthy?

There are large-scale studies that have investigated how unbalanced diets affect inflammatory bowel disease and other illnesses. The results of these studies indicate that the intake of so-called ultra-processed foods, i.e. highly processed foods, has a negative impact. These include, for example, industrially produced foods such as ready-made products, snacks or soft drinks, which often contain additives.

What is so harmful about these foods?

They can promote inflammation, change the composition of the gut microbiome and lead to metabolic acidosis. In this context, it is worth noting that inflammatory bowel diseases have increased with industrialisation - first in Western countries, then with a time lag in Asia, where ultra-processed foods and junk food restaurants only became established later.

This also brings us to the topic of obesity and the associated diseases of civilisation such as cardiovascular disorders and diabetes. What is the general state of nutritional behaviour among Swiss children and young people?

A survey on the dietary behaviour of children and young people between the ages of 6 and 17 is currently being conducted in Switzerland. However, the results of this MenuCH Kids study are not yet available. In Germany, the so-called Eskimo survey on the current nutritional situation and habits of children and adolescents was carried out as part of a long-term study on children's health (Kiggs).

One of the findings of this study is that more than one in five young people between the ages of 12 and 17 consume at least ten per cent of their daily calories as fast food. The data also shows an insufficient intake of calcium. This could be due to the fact that children and young people consume too few cow's milk products such as milk, cheese or yoghurt - or alternatively plant-based sources of calcium.

The usual recommendation for fruit and vegetables is five portions a day. Do people who eat less over a longer period of time consume too few micronutrients?

The Swiss Society for Nutrition even recommends seven and a half portions to prevent long-term health risks. That's 600 grams of fruit and vegetables a day for an adult. According to the latest wave of the Kiggs study from 2014 to 2017, only 14 per cent of children and young people eat five portions of fruit or vegetables a day. However, this does not mean that everyone else automatically suffers from deficiency symptoms because they consume fewer vitamins, minerals, trace elements and dietary fibres through fruit and vegetables.

What else should you pay attention to in your diet?

Another goal should be to avoid excessive energy intake from sugar and fat. And I'm not talking about the sugar and fat we consume in natural foods such as fruit or dairy products. I'm talking about unhealthy, highly processed foods and drinks with a high fat or sugar content, such as soft drinks, snacks or fast food.

The concept of the «optimised mixed diet» is described as a simple practical implementation of a healthy diet for children and young people. What exactly does it look like?

The optimised mixed diet is a nutritional concept designed to prevent deficiency symptoms and diet-related lifestyle diseases. It takes into account both scientific recommendations, for example for nutrient intake, and practical recommendations on food preferences and eating habits. As a result, children and young people meet their daily requirements for fluids, micro- and macronutrients and are also allowed to eat some biscuits or sweets, for example.

Pleasure is something beautiful. There can also be room for sweet and fatty foods in large quantities.

With younger children, parents can still control quite well how much and what they eat. This becomes more difficult in their teenage years at the latest.

That is correct. The more a child moves outside the family environment, the more likely they are to display unbalanced eating behaviour with an intake of convenience foods that is dictated from outside. The peer group, i.e. the circle of friends, becomes more important and social media also play a major role. Junk food companies have recently been focussing their marketing on social media stars who enjoy a high level of trust among children and young people. The influencer acts like a friend. If the cool guy buys the energy drink, I'll do the same. This encourages malnutrition from an early age.

So what can parents do?

Be a role model and promote a balanced diet and healthy lifestyle from an early age. Our lifestyle is moulded early in childhood. It is therefore important how and what is eaten in the family. Do we eat our meals together and take our time? Or does everyone eat when it suits their schedule? Do we eat a lot of ready-made products or do we endeavour to prepare as many meals as freshly as possible?

The advantage is that a certain imprint remains and teenagers also eat more fruit and vegetables if they have learnt this from the start. And even if more junk food is eaten in the teenage years, most people eventually return to the eating behaviour that their parents instilled in them.

What if my child only wants to eat pasta with cheese?

Many children are one-sided eaters at times. It often helps if the food is presented in an attractive way. However, there are always children for whom such creative attempts don't work. If you then exert constant pressure, you risk even more conflicts around food, which in the worst case can lead to eating behaviour disorders. Flavour and enjoyment are beautiful things, and there should also be room for sweet and fatty foods in moderation.

What do you think about parents wanting to feed their children a vegan diet?

A vegan diet is very demanding. This is because it is difficult to meet protein requirements with a purely plant-based diet during the growth phase, as is the supply of iron, calcium, iodine and vitamin B12. These components cannot be provided in sufficient quantities in a purely plant-based diet. Vitamin B12 must be permanently substituted for vegans. A purely vegan diet is particularly difficult for infants. There is a risk of malnutrition here, which is why we advise parents to seek advice from a nutritionist right from the start. However, most parents who choose this path do so very consciously and are well informed.

The Eskimo study revealed that boys in particular eat more sausages and meat than is recommended.

It's the same with my son. Now the question arises: Is this really bad or can it be tolerated during phases of growth? This food choice is probably intuitive to a certain extent due to the increased protein requirement. However, if you consume a lot of meat and sausage products on a permanent basis, this can have negative effects, for example on the cardiovascular system. This brings us back to the topic of long-term health prevention. Young people need to be educated about this and the consequences that nutrition can have.

There are several programmes that aim to promote sufficient exercise and a healthy diet.

Such programmes aimed at changing individual behaviour are good and important - but not enough. We need appropriate framework conditions that help to promote the consumption of healthy food, for example differentiated food taxation. And healthy food, i.e. food rich in fibre and nutrients, must be affordable for everyone. In addition to the parental home, schools should also impart nutritional knowledge and sensitise children to social media and influencers and their impact. This is the task that parents and schools must fulfil.