October 09, 2015 14:11 UTC


Why Getting Dirty Can Be Healthy for Children

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This is the VOA Special English Health Report.

A new study suggests that early exposure to germs strengthens the immune system. That means letting children get a little dirty might be good for their health later in life.

The study involved laboratory mice. It found that adult mice raised in a germ-free environment were more likely to develop allergies, asthma and other autoimmune disorders. There are more than eighty disorders where cells that normally defend the body instead attack tissues and organs.

They include rheumatoid arthritis, which attacks the joints; Crohn's disease, an inflammatory bowel condition; and juvenile diabetes. Hay fever, a common allergy, is also an autoimmune disorder.


Richard Blumberg is a professor at Harvard Medical School in Boston, Massachusetts. He says in nineteen eighty-nine, medical researchers sought to explain these diseases with what they called the "hygiene hypothesis." They proposed that the increasing use of antibacterial soaps and other products, especially early in life, could weaken immune systems.


RICHARD BLUMBERG: "The hypothesis has stated or suggested that early-life exposure to microbes is a very important determinant of later life sensitivity to allergic and so-called autoimmune diseases, such as hay fever, asthma, inflammatory bowel disease and others."

Now, Dr. Blumberg and a team have what they say is the first biological evidence to link early exposure to germs to stronger adult immune systems. They say this exposure could prevent the development of some autoimmune diseases.

In the adult germ-free mice, they found that inflammation in the lungs and colon was caused by so-called killer T cells. These normally fight infection. But they became overactive and targeted healthy tissue -- an autoimmune condition seen in asthma and a disease called ulcerative colitis.

Dr. Blumberg says the mice raised in a normal environment did not have the same reaction. He says their immune systems had been "educated" by early exposure to germs.

RICHARD BLUMBERG: "What was really most remarkable to us was the fact that once the education event provided by the microbes occurred in early life, it was durable and lasted throughout the life of the animal."

Rates of autoimmune disorders are rising worldwide, but mostly in wealthier, industrialized countries.

RICHARD BLUMBERG: "I think one obvious question, for example, that’s raised by these studies is the early life use of antibiotics and whether we need to be more careful in their prescribing."

Rob Dunn is a professor of ecology and evolutionary biology at North Carolina State University in Raleigh. He says the new study does not mean people should stop washing.

ROB DUNN: "Wash your hands, but don't do it with antimicrobial soap. Let your kids play in a reasonable amount of dirt and get outside and get exposed to a diversity of things."

The study appears in the journal Science.

And that's the VOA Special English Health Report. I'm Steve Ember.


Contributing: Jessica Berman

This forum has been closed.
Comment Sorting
Comments page of 5
by: Jorge Trujillo Pascuas
04/14/2012 4:12 PM
This article describes exactly what happens with careless chilcren in farmer
poor families in less develop countries; they grow up more healthy than others
whos parents have the means to care about them. Thank you VOA.

by: Mai Tran
04/13/2012 4:09 PM
i had no any health problems for long time living in pollution country, vietnam, Now i have some kind of allergies when i moved to live in U.S. My husband said my body immune system has been changing which is much weaker now.

04/12/2012 5:01 PM

04/12/2012 2:11 PM
I think this is an interesting topic for many people. It gives me some new knowledge. This is also a new research about health and useful for the younger mum. I like it!

by: Said Masoom
04/12/2012 7:25 AM
I am father of 8 children my senior son is in the first class of university and my jonnior dather in the age of 2. when i care my children from dirty they were more unresistened to the diseases .

by: Said Masoom
04/12/2012 7:22 AM
I am father of 8 children my senior son is in the first class of university and my jonnior dather in the age of 2. when i care my children from dirty they were more unresistened to the diseases .

by: Ms.Dieu Quynh-TTLady.
04/10/2012 12:49 AM
This article is so useful for young mothers like me. Thank VOA so much .

by: Tak
04/09/2012 9:02 AM
This article is meaningful so much to grow up children. So, should I stop to use electric-device or air washer to suppress airborne virus for children?

by: majed
04/09/2012 7:01 AM
In light of this report, my sons, egyptian kids in general, are the healthiest in the world, due to the daily dirt exposure they undergo. kids of the world, rise from bed and welter in dirt!!!

by: Binh
04/09/2012 3:19 AM
Probably, this early exercise will be like a vaccine for our health system later on when we grow up

Comments page of 5

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