Rat study shows dirty better than clean

[Guest guest]

Rat study shows dirty better than cleanBy SETH BORENSTEINAP SCIENCE WRITERhttp://seattlepi.nwsource.com/national/1501AP_Dirty_Rats.htmlWASHINGTON -- Gritty rats and mice living in sewers and farms seem to havehealthier immune systems than their squeaky clean cousins that frolic incushy antiseptic labs, two studies indicate. The lesson for humans: Cleanliving may make us sick.The studies give more weight to a 17-year-old theory that the sanitizedWestern world may be partly to blame for soaring rates of human allergyand asthma cases and some autoimmune diseases, such as Type I diabetes andrheumatoid arthritis. The theory, called the hygiene hypothesis, figuresthat people's immune systems aren't being challenged by disease and dirtearly in life, so the body's natural defenses overreact to small irritantss

uch as pollen.The new studies, one of which was published Friday in the peer reviewedScandinavian Journal of Immunology, found significant differences in theimmune systems between euthanized wild and lab rodents.When the immune cells in the wild rats are stimulated by researchers,"they just don't do anything they sit there; if you give them samestimulus to the lab rats, they go crazy," said study co-author Dr. , a Duke University professor of experimental surgery. He comparedlab rodents to more than 50 wild rats and mice captured and killed incities and farms.Also, the wild mice and rats had as much as four times higher levels ofimmunoglobulins, yet weren't sick, showing an immune system tuned to fightcrucial germs, but not minor irritants, said. He said what happenedin the lab rats is what likely occurs in humans: their immune systems havegot it so cushy they overreact to smallest of problems.

BR>"Your immune system is like the person who lives in the perfect house andhas all the food they want, you're going to start worrying about thelittle things like someone stepping on your flowers," said.Challenged immune systems - such as kids who grow up with two or more pets- don't tend to develop as many allergies, said Dr. Stanley Goldstein,director of Allergy & Asthma Care of Long Island. said his study has drawbacks because he can't be sure that the ageof the wild and lab rodents are equivalent, although he estimates the agesbased on weight. He also could not control what happened in the past tothe wild rats to see if they had unusual diseases before being capturedand killed.It would have been more useful had studied extremely young wildrodents because, according to the hygiene hypothesis, that's when theprotection from dirty living starts, said Dr. Stuart Levy, director of theCent

er for Adaptation Genetics and Drug Resistance at Tufts University.Human epidemiological studies have long given credence to the hygienetheory, showing that allergy and asthma rates were higher in the cleanerindustrialized areas than in places such as Africa. 's studies,looking at animal differences, may eventually help scientists find when,where and how environmental exposure help protect against future allergiesand immune disorders, said Goldstein, and Dr. Platt of the MayoClinic in Minn., both of whom were not part of 's studies. said he hopes to build a 50-foot artificial sewer for his nextstep, so that he could introduce the clean lab rats to an artificial dirtyenvironment and see how and when the immunity was activated.That may be the biggest thing to come out of the wild and lab rodentstudies, Platt said: "Then all of a sudden it becomes possible to exposepeople to the few things (that exercise the immune system) and gives themthe benefit of the dirty environment without having to expose them to thedirt."*The material in this post is distributed withoutprofit to those who have expressed a prior interestin receiving the included information for researchand educational purposes.For more information go to:http://www4.law.cornell.edu/uscode/17/107.htmlhttp://oregon.uoregon.edu/~csundt/documents.htmIf you wish to use copyrighted material from thisemail for purposes that go beyond 'fair use', youmust obtain permission from the copyright owner.

--Carol in IL

[Guest guest]

I knew I was doing the right thing by not having an immaculate house -- woo

hoo!!

=====================

From: doihavtasay@...

Date: Sat Jun 17 09:34:35 CDT 2006

DSIE <Down Syndrome Treatment >

Subject: Rat study shows dirty better than clean

 Rat study shows dirty better than clean

By SETH BORENSTEIN

AP SCIENCE WRITER

http://seattlepi.nwsource.com/national/1501AP_Dirty_Rats.html

WASHINGTON -- Gritty rats and mice living in sewers and farms seem to have

healthier immune systems than their squeaky clean cousins that frolic in

cushy antiseptic labs, two studies indicate. The lesson for humans: Clean

living may make us sick.

The studies give more weight to a 17-year-old theory that the sanitized

Western world may be partly to blame for soaring rates of human allergy

and asthma cases and some autoimmune diseases, such as Type I diabetes and

rheumatoid arthritis. The theory, called the hygiene hypothesis, figures

that people's immune systems aren't being challenged by disease and dirt

early in life, so the body's natural defenses overreact to small irritants

such as pollen.

The new studies, one of which was published Friday in the peer reviewed

Scandinavian Journal of Immunology, found significant differences in the

immune systems between euthanized wild and lab rodents.

When the immune cells in the wild rats are stimulated by researchers,

" they just don't do anything they sit there; if you give them same<BR>stimulus

to the lab rats, they go crazy, " said study co-author Dr.

, a Duke University professor of experimental surgery. He compared

lab rodents to more than 50 wild rats and mice captured and killed in

cities and farms.

Also, the wild mice and rats had as much as four times higher levels of

immunoglobulins, yet weren't sick, showing an immune system tuned to fight

crucial germs, but not minor irritants, said. He said what happened

in the lab rats is what likely occurs in humans: their immune systems have

got it so cushy they overreact to smallest of problems.BR>

" Your immune system is like the person who lives in the perfect house and<BR>has

all the food they want, you're going to start worrying about the<BR>little

things like someone stepping on your flowers, " said.

Challenged immune systems - such as kids who grow up with two or more pets

- don't tend to develop as many allergies, said Dr. Stanley

Goldstein,<BR>director of Allergy & Asthma Care of Long Island.<BR><BR>

said his study has drawbacks because he can't be sure that the age

of the wild and lab rodents are equivalent, although he estimates the ages

based on weight. He also could not control what happened in the past to

the wild rats to see if they had unusual diseases before being captured

and killed.

It would have been more useful had studied extremely young wild

rodents because, according to the hygiene hypothesis, that's when the

protection from dirty living starts, said Dr. Stuart Levy, director of the

Center for Adaptation Genetics and Drug Resistance at Tufts University.

Human epidemiological studies have long given credence to the hygiene

theory, showing that allergy and asthma rates were higher in the cleaner

industrialized areas than in places such as Africa. 's studies,<BR>looking

at animal differences, may eventually help scientists find when,<BR>where and

how environmental exposure help protect against future allergies<BR>and immune

disorders, said Goldstein, and Dr. Platt of the Mayo<BR>Clinic in Minn.,

both of whom were not part of 's studies.

said he hopes to build a 50-foot artificial sewer for his next

step, so that he could introduce the clean lab rats to an artificial dirty

environment and see how and when the immunity was activated.

That may be the biggest thing to come out of the wild and lab rodent

studies, Platt said: " Then all of a sudden it becomes possible to expose

people to the few things (that exercise the immune system) and gives them

the benefit of the dirty environment without having to expose them to the

dirt. " <BR><BR>*<BR><BR>The material in this post is distributed

without<BR>profit to those who have expressed a prior interest<BR>in receiving

the included information for research<BR>and educational purposes.For more

information go to:<BR><A href= " http://www4.law.cornell.edu/uscode/17/107.html "

target= " _blank " >http://www4.<WBR>law.cornell.<WBR>edu/uscode/<WBR>17/107.html</A\

><BR><A href= " http://oregon.uoregon.edu/~csundt/documents.htm "

target= " _blank " >http://oregon.uoregon.edu/~csundt/documents.htm

If you wish to use copyrighted material from this

email for purposes that go beyond 'fair use', you

must obtain permission from the copyright owner.--

Carol in IL