MEDICA.de talked to Professor Wieland Kiess, director of the university and children’s hospital in Leipzig about the actual state of knowledge about type-1-diabetes and environmental influences.
MEDICA.de: Professor Kiess, do environmental factors influence the chance to get type-1-diabetes, if people are carriers of risk genes?
Kiess: Maybe. This has been a difficult topic for many years. The environment always influences health. However, we do have some evidence that environmental influences also play a role in the development of type-1-diabetes.
MEDICA.de: What are these influences?
Kiess: It is certain, that proteins in cow milk play a critical role. If mothers breast-feed their children less than six months and use cow milk early, these children have a higher risk of developing type-1-diabetes. It is also assumed that viruses are significant in this combination, too. An example is the coxsackie-virus which weakens the immune system and can provoke diseases of the airways. Furthermore researchers assume an influence of rubella viruses. Nutrition which is rich in calories or environmental toxins is also a target of research.
MEDICA.de: You often talk about assumptions. Are there any studies that back up these assumptions?
Kiess: Yes, on the basis of expermimental research and cohort studies. Scientists do research all over the world, in Europe first of all in Scandinavia. But we have to interpret those results carefully. In fact, experiments on mice showed a positive combination of coxsackie viruses and diabetes, but not every child gets diabetes after a common cold. However, the scientific findings only give us hints that environmental factors may have an influence on type-1-diabetes and they are only pieces of a large puzzle. The only clear evidence we have so far is the influence of breast feeding. Researchers found in a study with mice that nitrosamines in drinking water resulted in diabetes but we cannot apply these results to humans easily.
MEDICA.de: And how exactly do these influences from the environment destroy beta cells in the pancreas as it happens with type-1-diabetes?
Kiess: Environmental influences can cause autoimmune diseases. Let’s take the example cow milk: Foreign proteins are ingested by the child whose body builds antibodies against them. But these antibodies in turn may not destroy the foreign proteins but the beta cells in the pancreas which produce insulin. A similar process takes place when certain viruses enter the body when it is similar to the islet cells. Also, islet cells can be overstrained with a diet very rich in calories.
MEDICA.de: Is there a point in time on which the body reacts extra sensitive on certain environmental factors in the combination with type-1-diabetes?
Kiess: This is very different. If a woman comes down with rubella during pregnancy and she is not immune against the disease, the viruses affect the development of the embryo in the womb. An embryopathy caused by rubella can be the consequence, also diabetes. But the disease will not break out directly after birth, maybe it will during adolescence. If we assume that cow milk is the significant factor we will find the promoting factors in babyhood.
MEDICA.de: Are environmental factors also able to cause diabetes in humans who do not have risk genes for diabetes?
Kiess: In principle, yes. But these are individual cases, for example when considering rubella viruses in pregnancy. But normally type-1-diabetes is a disease which is determinated by a combination of environment and risk genes.
MEDICA.de: Is it possible to protect oneself against type-1-diabetes that is triggered by environmental factors?
Kiess: We need more research to answer this question. Breastfeeding during the first six months is surely advisable. Another preventive approach could be the administration of vitamin B3, also called nicotinamid. Researchers expected that this vitamin could protect beta cells against destruction. But there were neither significant results in the European-Canadian study ENDIT nor in the German study DENIS. My only advice: do sports, breathe fresh air and drink plenty of water.