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."
Re:Of course it is (Score:5, Interesting)
Not entirely true. Grains harvested in the Mesopotamian region for the past 20,000 years contain a fungus that produces potent antibiotics. This was discovered by analyzing those who drank beer (albeit over a paltry 8,000 years) and finding the residue in the bones. Once the source was traced back to the fungus, it was obvious that anyone eating grains in the Middle East since the advent of farming (20,000 years ago) will have had "modern medicine".
http://www.wired.com/wiredscience/2010/09/antibiotic-beer/ [wired.com]
Before then? Well, honey is another rich source of antibiotics. It's also a hygroscopic material, so applying it to burns will not only kill bacteria but will also reduce inflammation, build-ups of toxins, etc.
It's unclear when Neolithic man first developed brain surgery, but there's no question that he did and that patients survived.
So man has had a LOT of medical assistance for a very long time. Not as much as in modern times, true, but it wasn't zero. Not by a long way.
Just a hypothesis (Score:5, Interesting)
It's a good one, but there are several competing theories out there too. One of the best I've seen is the correlation between acetaminophen use in children and the development of asthma in children [nytimes.com]. It just so happens that clean, microbe-adverse developed nations have much more access to acetaminophen than dirty, unsanitized third world countries....
I guess I'd be a counterexample... (Score:3, Interesting)
Re:Of course it is (Score:4, Interesting)
Re:Of course it is (Score:2, Interesting)
http://www.merckmanuals.com/home/womens_health_issues/biology_of_the_female_reproductive_system/female_internal_genital_organs.html?qt=&sc=&alt=
(In the boxed part How Many Eggs?)
>Only about 400 eggs are released during a woman's reproductive life, usually one during each menstrual cycle. Until released, an egg remains dormant in its follicle-suspended in the middle of a cell division. Thus, the egg is one of the longest-lived cells in the body. Because a dormant egg cannot perform the usual cellular repair processes, the opportunity for damage increases as a woman ages. A chromosomal or genetic abnormality is thus more likely when a woman conceives a baby later in life.
The eggs have higher accumulated "data error" than most cell, so there is a reason why it is not genetically desirable to have the older female produce offspring. Menopause is probably a way for nature to reduce that number.