Reminder: LNCI Brown Bag lunch in Westerville TUESDAYJanuary 15, 2010
Dispatch story notes attendance at Hocking Hills park is upJanuary 17, 2010
Sunday, January 17, 2010 3:42 AM
By Misti Crane
THE COLUMBUS DISPATCH
Cleaning supplies of all sorts are plastered with claims of bacteria-annihilating powers.
Hand sanitizer is ubiquitous, especially since the arrival of H1N1 flu. And plain old soap isn’t enough anymore, the soap companies tell us, touting concoctions that kill “99.99 percent of germs.”
But a growing body of scientific evidence is pointing to links between hypersanitary lifestyles and health problems.
Recently, a study of 1,534 Filipinos followed from before birth until early adulthood showed that those exposed to more bacteria had lower levels of a protein that indicates inflammation. Cardiovascular problems and other diseases increasingly are being linked to inflammation.
On average, babies exposed to more germs, including from animal feces, had lower levels of C-reactive protein when they became young adults.
The research, published in the journal Proceedings of the Royal Society B: Biological Sciences, was led by Thomas McDade, an associate professor of anthropology at Northwestern University and a fellow in the Institute for Policy Research. The researchers used statistical modeling to draw the connection between factors early in life and C-reactive protein levels in adulthood.
McDade advised caution when extrapolating too much from the study and is eager to pursue follow-up research, but he said this and other studies should at least give parents pause when they reach for another antibacterial product.
Young immune systems, like young brains, need stimulation, he said.
“What I think is important is exposure to common, everyday germs in dirt, in mud, that probably don’t lead to an infection but have an important role in priming our immune systems.”
Doing reasonable things to prevent the spread of known viruses and bacteria is a good thing, he said. But trying to keep your little one from ever encountering a germ might cause harm in the long term.
Studies, many comparing diseases in the developed world with those in less-developed countries, have led to the “hygiene hypothesis” — the idea that a more-protected immune system might lead to higher rates of certain illnesses.
“It’s healthy for us to get sick from time to time. It helps educate our body what to attack and what not to attack,” said Dr. Bradley Van Sickle, a pediatric endocrinologist at Akron Children’s Hospital.
“Washing your child from head to toe all day long and not letting them play with other kids is not helpful.”
Of particular concern in his field is the rise in Type 1 diabetes. According to an analysis of 37 studies over the past 40 years, the incidence worldwide is increasing by 3 percent annually, and some people think an increasingly sanitary society is at play.
Some studies have shown that living in a home with animals, or on a farm, decreases the likelihood a person will develop asthma, said Dr. Jonathan Bernstein, an allergy specialist and professor at the University of Cincinnati College of Medicine.
But there are many exposures — or lack thereof — that might contribute, he said. And don’t forget the role of genetics.
It will be some time before scientists fully understand the role of hand sanitizers and other antibacterial products widely used today, Bernstein said.
There’s no question that some bacteria are good for us, said Dr. Kurt Stevenson, a professor in Ohio State University’s division of infectious diseases. In our guts, in particular, the absence of bacteria can cause mayhem.
In the hospital setting, doctors try to focus on known high-risk situations when using strong antimicrobial products, but use regular soap in areas where it’s appropriate, he said.
And at home?
“Probably on a day-to-day basis, just common sense and regular soap is probably adequate.”