Are we too clean ?
As parents we always try to do the best we can for our kids. Sometimes our best is right, sometimes it is wrong but either way - we do our best!
Over the past few decades, there has been a huge increase in the numbers of children with asthma and allergies worldwide, particularly in developed countries. In 1989, an epidemiologist writing in the British Medical Journal suggested that the rise in allergies might be due to declining family sizes and higher standards of cleanliness; these two circumstances provide young children with less exposure to germs. This, in turn, is thought to give children's still-developing immune systems less practice in fighting off intruders. The result, the theory goes, is that the under-challenged immune system wants to be used, so it becomes primed to see harmless substances like dust and pollen as dangerous invaders, leading to allergies and asthma.
Recent studies show that there may be some truth to this idea, which has come to be known in medical circles as "the hygiene hypothesis". In 1997, a study of almost 12,000 families in England and Scotland found that the more children a family had, the less the incidence of asthma. A May 2000 study in an American journal reported that among almost 1,200 teenagers in Canada, those who grew up on farms were 40 per cent less likely to have asthma than their urban and suburban counterparts.
And in a more comprehensive study, scientists at the University of Arizona followed a group of 1,035 children from infancy until they were as old as 13. They found that among babies under six months, those who had older siblings or were in nursery were more likely to have asthma symptoms such as wheezing. But after the age of six, these same children were 40 per cent less likely to be suffering from asthma.
"What do siblings, animals, and nursery have in common?" asks Dr Thomas Ball, assistant professor of Clinical Paediatrics at the University of Arizona and one of the authors of the study. It sounds unpleasant, but the answer is probably contact with trace amounts of faeces. Ball speculates that what actually causes that decrease in asthma later isn't actually the number of infections a baby has, but rather the amount of contact she has with endotoxins, which are substances that are given off by bacteria when they die. Faeces are loaded with them.
But the important thing to note from Ball's study is that the window of opportunity for affecting the developing immune system seems to occur during the first year of life. Research has shown that a baby's immune system begins preparing for microbial onslaught even before birth, with the placenta acting as a filter that lets through small amounts of innocuous allergens and microbes. Babies, it seems, are born ready to have their immune systems challenged.
Article originally published at:- http://www.babycentre.co.uk/baby/dailycare/canyoubetooclean
