Vallo Tillman: The hygiene hypothesis is not yet a theory

by Thijs Westerbeek

A new study in Northern Europe is specifically designed to verify whether children need be in contact with pathogens in their early years to help them develop a strong immune system.

The so-called hygiene hypothesis claims young children need to get in contact with a number of relatively benign pathogens to develop a robust immune system. It could help explain both the rise of allergies in modern western society and the occurrence of auto-immune diseases, especially diabetes type 1. The Diabimmune study, funded by the EU, focuses on 4,500 children living at the border between the Russian region of Karelia, Estonia, and Finland. These three countries are at different stages of development, yet their population is genetically similar. Vallo Tillman, professor of paediatrics and head of the Children's Clinic of Tartu University in Estonia, talks to on how this study is attempting to confirm the hygiene hypothesis.

What exactly is the role of Estonia in the study?

Estonia serves as the 'country in the middle.' It is rapidly changing from a soviet-type society to a country, which is very much like a modern Western nation. And the situation from the perspective of hygiene is changing at the same time. Here, we can see allergies and possibly diabetes type 1 rising as the country gets 'cleaner.'

What are the challenges associated with the organisation of such a study?

The biggest challenge is to find enough children. Estonia is a very small country. So we quickly found that just the Tartu region would never be enough. We therefore searched all over Estonia. In the end, we found 330 infants for our 'birth cohort', composed of infants of up to 3 months old, and 1,681 for the second control group, composed of of between 3 and 5 years old. This is quite close actually to the official targets of 360 and 2,000, respectively. Our sample is also comparable to the numbers of the Finish arm of the study.

What are the pitfalls when it comes to interpreting the data?

We do have a few problems. The lack of test subjects in Russian Karelia is one of them. Our colleagues in Russia had the most difficult time because of the horrific bureaucracy which still exists down there. As a result, the end of the project has been postponed to February 2014. Even so, we may be forced to just compare Finland and Estonia on certain aspects of the study. And this is a problem in itself. Estonia is already very close to Finland, when it comes to the matter of . By now, the two countries are becoming too similar. We have seen it coming because we already noticed a steep rise in type 1 diabetes in Estonia.

The study is not over yet, but do preliminary results tend to confirm the hygiene hypothesis?

Yes they do, as far as allergies are concerned. But, in that respect, the hypothesis was already standing very firm. However, I dare not yet speculate about the conclusions concerning diabetes type 1. Unfortunately for us—and fortunately for them—not many patients have developed type 1 diabetes. If you ask me whether the can be changed into a proper theory, I would say it is coming closer. But we are not there yet. Meanwhile, by now, we have established a very nice cooperation between our three countries. I would be not at all surprised if, in the future, there are more projects like this one.

add to favorites email to friend print save as pdf

Related Stories

Does too much hygiene cause diabetes?

Jan 09, 2014

The incidence of auto-immune diseases like type 1 diabetes and allergies has risen dramatically in developed countries over the past fifty years. The reasons for this trend are not fully understood but a theory known as ...

Estonia tops EU drug overdose deaths list

Feb 13, 2013

Officials in Estonia raised the alarm Wednesday after a report into drug use in Europe found that the small Baltic nation had the highest incidence of deaths from drug overdoses in the EU.

Estonia says Europe overreacted to US cyber spying

Jul 11, 2013

Europeans have overreacted to allegations that the United States had been snooping on them and vacuuming up huge amounts of phone and Internet data, cyber-savvy Estonia said in an interview published Thursday.

Estonian brown bears head west

Nov 23, 2012

Estonia's thriving brown bear population has spread nationwide after hunters eased up in their traditional territory, an expert in the Baltic state said Friday.

Recommended for you

Added fructose is a principal driver of type 2 diabetes

Jan 29, 2015

Recent studies have shown that added sugars, particularly those containing fructose, are a principal driver of diabetes and pre-diabetes, even more so than other carbohydrates. Clinical experts writing in Mayo Clinic Proceedings challe ...

Support found for peer-mentoring diabetes management program

Jan 29, 2015

Managing type 1 diabetes is a never-ending task that requires multiple blood glucose tests, carbohydrate calculations and insulin injections or infusions. This constant effort to control the disease is daunting at any age ...

How does DPP-4 inhibition affect liver function?

Jan 27, 2015

(HealthDay)—Dipeptidyl peptidase-4 (DPP-4) inhibition may attenuate hepatic steatosis and insulin resistance induced by the Western diet (WD) through hepatic lipid remodeling and modulation of hepatic mitochondrial ...

User comments

Adjust slider to filter visible comments by rank

Display comments: newest first

not rated yet Jan 09, 2014
I think they mean that "it is not yet theory". 'Theory' in science means a hypothesis has been confirmed (proved). When we say 'a theory' we are using common parlance for the scientific term 'hypothesis', which refers to an unconfirmed proposition (not yet demonstrated observationally or experimentally).

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.