Early Exposure To Germs Has Lasting Benefits 136
ananyo writes "Exposure to germs in childhood is thought to help strengthen the immune system and protect children from developing allergies and asthma, but the pathways by which this occurs have been unclear. Now, researchers have identified a mechanism in mice that may explain the role of exposure to microbes in the development of asthma and ulcerative colitis, a common form of inflammatory bowel disease. The researchers show that in mice, exposure to microbes in early life can reduce the body's inventory of invariant natural killer T (iNKT) cells, which help to fight infection but can also turn on the body, causing a range of disorders such as asthma or inflammatory bowel disease (abstract). The study supports the 'hygiene hypothesis,' which contends that such auto-immune diseases are more common in the developed world where the prevalence of antibiotics and antibacterials reduce children's exposure to microbes."
Of course it is (Score:5, Insightful)
Humanity (or human like creatures) survived for several hundred thousand years without modern medicine. If the body was not capable of developing defenses to disease we wouldn't still be here.
Re:Of course it is (Score:5, Insightful)
On the other hand, the average life span of human being was around 30 years in those early days at best. It is modern medicine and general quality of life that extends that to 70+ years.
Re:Sorry (Score:5, Insightful)
Finding this hard to swallow personally. I was born with pneumonia and had chronic infections early in life. In my 20s I am still plagued by allergies, asthma and generally poor health despite generally good habits as far as diet, exercise, and hygiene. I cringe when I think about what kind of state I'd be in if I didn't.
The theory goes that it's too late for sloppy hygiene to help you much, now, but if you ate more dirt as a kid, you'd be healthier.
Most of my anecdotal observations in life tend tend to agree: life in a bubble isn't good for you, even if you never leave it.
Re:Sorry (Score:5, Insightful)
Not of course (Score:4, Insightful)
This isn't a question of if the body can defend itself, but if it is better to let it do so or not. For example you can also heal from a broken bone, however it is better to not have to. Near as we can tell it is all downsides, no upsides to breaking bones. When you are young there are usually little long term downsides (at least if it isn't major) but still no upsides.
What these studies indicate is that is not the case with illness. It is actually better to get sick at an early age than not to. It looks like it is even more of a matter than it helps develop your defenses, but that they may actually be more likely to turn against you if they aren't used.
That is not at all obvious, and rather interesting research.
Re:Of course it is (Score:3, Insightful)
Typically these numbers include an extremely high infant mortality rate, without which the difference is significantly smaller.
Of course. But that doesn't mean that 0 year olds dying back then magically stopped being a problem. It merely points to a deficiency of describing a distribution with just its first moment, the mean.
Re:This explains it (Score:5, Insightful)
Glad this is finally being proven. (Score:3, Insightful)
All those nutcases throwing around how our produced-foods society is causing all these new illnesses.
Is it hell. It is because we are being stupidly over-clean.
Biology never evolved in a sterile laboratory, it evolved with constant bombardments of infection that helps the body calibrate sensitivity, in exactly the same way that your skins touch sensors adapt to air pressure, your eyes adapt to light and countless others. Why should it have been any different to the immune systems sensitivity?
In fact, there is a partial truth to the produced-foods part, and that is more of a case that the food is too clean rather than microbe-filled.
We have been taught that all possible microbes in food are terrible, but are they?
Only a few select sources of food are overly-infected with nasty things, specifically beef supplies (which are just horrible for you in general)
Most other things are completely safe eaten raw. That includes milk, which has been blasted as dangerous to drink raw, but actually aids people with autoimmune. (now if only there was an actual full-on study for it since the sporadic cases of it all around are promising)
Fact is, if there is any sort of food source infection, the odds of you even getting it are as likely as you getting madcow disease or some other rare illness from eating, simply due to all the safeguards we have in taking care of animals, tracking food all across the world, etc.
Overly-cooked foods are of course bad for you, since burned foods contain carcinogens. But good luck getting anyone off that, some people like their food charred a little. You'll never be able to stop the grill lovers either.
As a person with crohns, it pleases me more is being found out about the intestinal tract and how the immune system functions there.
There was a recent huge discovery on how the immune functions were expressed there to prevent it from attacking vital resources and nutrients.
As an illness that is claiming so many more people due to this clean-freakishness that has become of society in recent years, it is about time people start to realize that clean isn't all there is to being healthy.
Close, Bruce (Score:4, Insightful)
What made (past tense) you stronger is the stuff that killed half of each generation of your ancestors' competition.
What doesn't kill you delays the inevitable, but if it doesn't keep you from reproducing it improves the quality of your children's mates and thus makes your grandchildren stronger.
Not exactly (Score:4, Insightful)
What these studies indicate is that is not the case with illness. It is actually better to get sick at an early age than not to.
s/sick/exposed to some bacteria/ There's a big difference between being exposed to common bacteria of the soil and animal digestive tracts and coming down with smallpox, meningitis, etc. From the articles I've read, the protective effect is seen with completely harmless bacteria, so there's no reason to claim benefits from exposure to pathogens. Especially when you consider that infant diarrhea accounted for the majority of that 50% infant mortality.
With some exceptions. If your lifetime chances of avoiding a pathogen are slim, it may be better to be esposed in infancy while getting lots of maternal antibodies with every meal, assuming that Mama also gets exposed often enough to maintain a high antibody titre. That process is why polio was less of a threat in the 17th century, where the stuff was in the water supply all over the world, than in the 20th where we were actually doing things that blocked routine fecal-oral transmission.
All in all, with pathogens I prefer vaccination where possible.
Re:Glad this is finally being proven. (Score:5, Insightful)
Only a few select sources of food are overly-infected with nasty things, specifically beef supplies (which are just horrible for you in general)
Most other things are completely safe eaten raw. That includes milk
I hate to break it to you, but milk and beef comes from the same filthy animal.
Re:Of course it is (Score:4, Insightful)
At least the benefit of helping kids with the grandchildren outweighs the benefit of having more children at that age. It is well known that genetic defects like Down Syndrome rise dramatically once a woman is past her mid- to late 30s.
You also have significantly rising mortality without medicine so as long as it's not pretty much ensured that you'll last for another 10+ years the high investment in a pregnancy isn't worth it any more.
Evolution is always right.
Re:I guess I'd be a counterexample... (Score:4, Insightful)