interesting article in NY Times about the possible reasons behind the higher prevalence of autoimmune disease in the wealthier parts of the world.
researchers followed a group of newborns who were genetically at risk of developing Type 1 diabetes in Finland (highest prevalence of Type 1 diabetes in the world), Estonia and right across the border from Finland, in Russia, in a population with a very similar genetic profile to the Finnish, but a very different economic situation.
It turns out it's less about living in a hygienic environment free of pathogens, and more about how early on in life your immune system has to fight these pathogens. When you're infected later in life, the chances of this infection triggering the start of an autoimmune illness are much higher.
This could explain why living in less hygienic surroundings (drinking untreated well water, for example) lowers your chances of developing an immune related illness later in life. (The life expectancy in these countries is generally a lot lower though, so it's not all that straightforward.)
researchers followed a group of newborns who were genetically at risk of developing Type 1 diabetes in Finland (highest prevalence of Type 1 diabetes in the world), Estonia and right across the border from Finland, in Russia, in a population with a very similar genetic profile to the Finnish, but a very different economic situation.
article said:The scientists focused on a microbial byproduct called endotoxin, which usually spurs white blood cells into action.
Both communities of microbes produced endotoxin, but not, it turned out, of equal potency. Endotoxin from Russian microbes strongly stimulated human immune cells. And when given to diabetes-prone mice early in life, it lowered their chances of developing the condition. But the Finnish endotoxin was comparatively inert. White blood cells didn’t register its presence, and it failed to protect mice from developing autoimmune diabetes.
These findings are very preliminary, but they support a decades-old (and unfortunately named) idea called the hygiene hypothesis. In order to develop properly, the hypothesis holds — to avoid the hyper-reactive tendencies that underlie autoimmune and allergic disease — the immune system needs a certain type of stimulation early in life. It needs an education.
It turns out it's less about living in a hygienic environment free of pathogens, and more about how early on in life your immune system has to fight these pathogens. When you're infected later in life, the chances of this infection triggering the start of an autoimmune illness are much higher.
This could explain why living in less hygienic surroundings (drinking untreated well water, for example) lowers your chances of developing an immune related illness later in life. (The life expectancy in these countries is generally a lot lower though, so it's not all that straightforward.)