Allergies: Why a Little Dirt Can Be Good for You

Children who grow up in a clinically clean environment are more likely to fall ill. Research shows that a little dirt can help to strengthen the immune system.

Our great-grandparents knew this well: you could lie in the hay or drink birch sap without fear of sneezing or gasping for breath. Hay fever and asthma were already common 100 years ago, but nowhere near to the extent they are today. Eighty years ago, fewer than 2% of the population suffered from pollen allergies. Today the figure is between 15 and 20 per cent.

Atopic dermatitis is also rising sharply: between 15 and 30 per cent of children and between 2 and 10 per cent of adults are affected by this skin condition. According to the European Centre for Allergy Research, in 2015 around half of all people in Europe suffered from some form of allergy.

Why is this? More recent research shows that exposure to microorganisms plays a role in whether allergies develop. Secondly, excessive hygiene harms the immune system. Hygiene products normally fight dangerous microorganisms such as bacteria, viruses or fungi successfully. Sometimes, however, the body over-reacts in the form of an allergy. The immune system becomes too sensitive and then reacts even to harmless substances such as pollen, house dust or cat hair, with skin rashes, hay fever or even asthma.

The Effect of Animal Faeces

The immune system protects the body. We start out with a genetically inherited blueprint, but the system learns as it goes. With each new infection it learns to deal with a particular pathogen. This also explains why it is perfectly normal for children to catch colds frequently in their first years. In the first year of life they may fall ill seven times on average, and between the ages of one and four as many as nine times a year. Adults, by contrast, have an infectious illness around two to three times a year on average.

The reason is that pathogens can spread easily. Only 100 years ago, many people lived under one roof with their animals, and so with their microbes and bacteria too. Basic sanitary facilities were lacking. City dwellers were also in constant contact with a wide variety of microbes, bacteria and parasites. On top of that, refrigerators only became common in the middle of the twentieth century.

Today most Swiss children could eat off the floor. This seems ideal at first glance, yet near-sterile living conditions can backfire: in a clinically clean environment, a child’s defence mechanism simply lacks practice in fighting microbes. In the late 1990s, Swiss researchers found that farm children were three times less likely to develop asthma and hay fever than children in the city. The finding was later confirmed by international studies. They showed that the risk of allergy is lower because farm children’s immune systems are constantly stimulated and strengthened through contact with bacterial toxins. The more often children come into contact with bacteria and viruses through animal droppings or dust, the less often they suffer from hay fever or asthma.

For the immune system, it is best to become accustomed to the ordinary living environment as early as possible. At the allergy clinic for children and adolescents in Davos, it was found that children who had contact with farm animals in stables before their first birthday had a lower risk of developing allergies. In village children, white blood cells respond more strongly to certain protein molecules, which allow the immune system to recognise microorganisms better and react to them.

What Excessive Hygiene Leads To

A long-term study shows that a child’s immune system is already shaped before birth. A child’s immune system changes, for example, if the mother remained stable and healthy during pregnancy. Other factors are also thought to play a part, possibly diet and drinking fresh cow’s milk.

Experts agree that excessive hygiene is counterproductive. An interesting study was carried out on this subject under the name of the “hygiene hypothesis”. This does not mean that people should stop washing or that children may run around dirty. It simply calls for common sense. When a child is playing and some sand ends up in their mouth, there is no need to panic: it is not a catastrophe, it is perfectly normal.

Deliberately exposing children to dirt as a kind of vaccination is not the answer, however. It helps to know that contact with certain bacteria can stimulate the immune system. But once the problem has appeared and a child already suffers from hay fever, a holiday on a farm or a visit to stables is not advisable, as it may be counterproductive.

The Immune System: How Children Stay Healthy

Keep children from getting chilled, as this weakens the body’s defences. If you follow these tips, your child will fall ill less often, and regular walks in every season will strengthen your immune system as well as theirs.

  • All outdoor activities stimulate the immune system. Take your child to the park, the playground or the woods, every day if possible. Sunlight also helps to strengthen the immune system.
  • The right clothing: good-quality seasonal footwear, warm socks, a breathable jacket and a thick scarf when you take children outside in winter.
  • A balanced diet with plenty of fruit and vegetables, and regular meals in a calm atmosphere, have a positive effect on the immune system.
  • Make sure your children drink enough. Otherwise the mucous membranes dry out and become more susceptible to pathogens.
  • Vitamin C on its own cannot prevent a cold. At best it can help to ease the symptoms. Lemon juice (diluted with hot water and sweetened with honey), fresh orange juice, sweet peppers (cut into strips) or kiwi (sliced or puréed) are especially rich in vitamin C.
  • Let your child get enough sleep. Sufficient rest further strengthens the immune system.
  • Herbal remedies to boost immunity should not be given to children under four, and even then only for a short period (a few days). The reason: the immune system of young children is still immature.

When we feel good, we are less prone to illness. So let joy in life, fun and good relationships support the health of the whole family.