Let’s Add a Little Dirt to Our Diet - excellent overview! NYT

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excellent overview!

Dirtying Up Our Diets

By JEFF D. LEACH

http://www.nytimes.com/2012/06/21/opinion/lets-add-a-little-dirt-to-our-diet.htm\

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OVER 7,000 strong and growing, community farmers’ markets are being

heralded as a panacea for what ails our sick nation. The smell of fresh,

earthy goodness is the reason environmentalists approve of them,

locavores can’t live without them, and the first lady has hitched her

vegetable cart crusade to them. As health-giving as those bundles of

mouthwatering leafy greens and crates of plump tomatoes are, the

greatest social contribution of the farmers’ market may be its role as a

delivery vehicle for putting dirt back into the American diet and in the

process, reacquainting the human immune system with some “old friends.”

Increasing evidence suggests that the alarming rise in allergic and

autoimmune disorders during the past few decades is at least partly

attributable to our lack of exposure to microorganisms that once covered

our food and us. As nature’s blanket, the potentially pathogenic and

benign microorganisms associated with the dirt that once covered every

aspect of our preindustrial day guaranteed a time-honored

co-evolutionary process that established “normal” background levels and

kept our bodies from overreacting to foreign bodies. This research

suggests that reintroducing some of the organisms from the mud and water

of our natural world would help avoid an overreaction of an otherwise

healthy immune response that results in such chronic diseases as Type 1

diabetes, inflammatory bowel disease, multiple sclerosis and a host of

allergic disorders.

In a world of hand sanitizer and wet wipes (not to mention double tall

skinny soy vanilla lattes), we can scarcely imagine the preindustrial

lifestyle that resulted in the daily intake of trillions of helpful

organisms. For nearly all of human history, this began with maternal

transmission of beneficial microbes during passage through the birth

canal — mother to child. However, the alarming increase in the rate of

Caesarean section births means a potential loss of microbiota from one

generation to the next. And for most of us in the industrialized world,

the microbial cleansing continues throughout life. Nature’s dirt floor

has been replaced by tile; our once soiled and sooted bodies and clothes

are cleaned almost daily; our muddy water is filtered and treated; our

rotting and fermenting food has been chilled; and the cowshed has been

neatly tucked out of sight. While these improvements in hygiene and

sanitation deserve applause, they have inadvertently given rise to a set

of truly human-made diseases....

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