Monday, June 20, 2005
The virtues of dirt
By Ezekiel J. Emanuel, a Chicago oncologist and bioethicist. He is the co-author of "No Margin, No Mission."
Published June 20, 2005
We now live in an antiseptic society. We have become phobic about bugs and germs.
Go to the supermarket and you are greeted with wipes to remove the bacteria from the handles of the shopping cart. Antibacterial soaps and dishwashing liquids proliferate. Children at day-care centers are constantly getting their hands splashed with antibacterial gels that require no washing to keep them germ-free. You can buy antiviral facial tissues--let's leave aside that they don't work.
Being clean and hygienic to a degree is certainly important and adds to health. Communal hygiene improvements, largely through better housing and sanitation, in the late 19th Century dramatically increased life expectancy in the U.S. And certainly having physicians and other health-care workers not carry bacteria from one patient to another is essential.
But when cleanliness tips over into an obsession, into an all-encompassing war to protect us against coming into contact with every bacterium and virus, it may well pose serious long-term dangers.
A growing body of data is intimating the long-term consequences of this antiseptic craze, particularly if it is exercised among young children. A recent study showed that people who grew up with brothers and sisters in the first six years of life were much less likely to develop multiple sclerosis, a disease that is probably the result of an autoimmune response against one's own nerve tissue. Indeed, so protective were siblings, that having contact for five out of the first six years of life with a sibling almost eliminated the risk of getting multiple sclerosis.
These data are epidemiological associations, not causally proven by randomized trials, and therefore controversial. But similar findings have been reported for a range of allergic and autoimmune diseases such as asthma, allergies, type 1 diabetes, polio and even some cancers of the blood and lymph system.
Are brothers and sisters protective against disease? What a new twist to sibling rivalry! It is unlikely that genes are a large part of the explanation, mainly because people who migrate from places with low rates of these allergic and autoimmune diseases quickly come to have the higher rates of their new home.
A growing body of evidence suggests that the likely explanation is, as every parent knows, that bothers and sisters bring home infections. They are a veritable cesspool of viruses and bacteria. And this, it appears, is a good thing!
Why is having an infection seemingly good for children?
The explanation is all part of what is called the "hygiene hypothesis," which really should be called the "dirt hypothesis." Studies suggest that infections early in life seem to add an element of better control or regulation of the immune system. Viruses and bacteria seem to stimulate the production of special immune regulatory cells whose effect goes beyond killing the germs to dampening overactive immune responses. This is just a hypothesis and still subject to controversy, but there is considerable animal research and epidemiological data supporting it.
One way to get more mild infections is to have more siblings who bring the little germs home from day care, school, the playground or their friend's house. Just playing with many more children--that cesspool of viruses and bacteria--is another way to get more infections. Another way is not to be treated with antibiotics for every viral infection--a bad practice for a number of reasons, including breeding resistance among bacteria and maybe even increasing the chances of autoimmune diseases. The lesson: More germs early in life appear to protect against the dreaded autoimmune diseases later in life.
Scientists have theorized that smaller families--therefore fewer siblings and fewer infections early in life--have led to increases in multiple sclerosis and other autoimmune diseases. By adding all these antigerm gels, soaps, creams, tissues and wipes, we are really trying to raise our children in an antiseptic society and this may well have its own long-term consequences for increasing the rate of autoimmune diseases.
This seems like it could be a repetition of the fast-food craze of the 1960s and 1970s. So desirable at the start: novel, convenient, tasty--especially with all that salt--and slickly marketed to make us think eating fast will make us efficient and happy. But then it becomes ingrained in everyday activities where the adverse consequences, which are initially hidden, finally become magnified and obvious. Junk food has led to an epidemic of terrible nutritional habits and obesity, imposing social costs related to health care, farming, changes in seat sizes and other aspects of public facilities that far outweigh short-term corporate profits.
Instead of cleaning surfaces with antibacterial wipes and squirting antibacterial gel on children's hands, we should celebrate dirt. Encourage your children to play with other children, and get runny noses and other mild infections. It is likely to be good for them. Better a mild cold or cough than asthma, multiple sclerosis, diabetes or cancers later in life.
Published June 20, 2005
We now live in an antiseptic society. We have become phobic about bugs and germs.
Go to the supermarket and you are greeted with wipes to remove the bacteria from the handles of the shopping cart. Antibacterial soaps and dishwashing liquids proliferate. Children at day-care centers are constantly getting their hands splashed with antibacterial gels that require no washing to keep them germ-free. You can buy antiviral facial tissues--let's leave aside that they don't work.
Being clean and hygienic to a degree is certainly important and adds to health. Communal hygiene improvements, largely through better housing and sanitation, in the late 19th Century dramatically increased life expectancy in the U.S. And certainly having physicians and other health-care workers not carry bacteria from one patient to another is essential.
But when cleanliness tips over into an obsession, into an all-encompassing war to protect us against coming into contact with every bacterium and virus, it may well pose serious long-term dangers.
A growing body of data is intimating the long-term consequences of this antiseptic craze, particularly if it is exercised among young children. A recent study showed that people who grew up with brothers and sisters in the first six years of life were much less likely to develop multiple sclerosis, a disease that is probably the result of an autoimmune response against one's own nerve tissue. Indeed, so protective were siblings, that having contact for five out of the first six years of life with a sibling almost eliminated the risk of getting multiple sclerosis.
These data are epidemiological associations, not causally proven by randomized trials, and therefore controversial. But similar findings have been reported for a range of allergic and autoimmune diseases such as asthma, allergies, type 1 diabetes, polio and even some cancers of the blood and lymph system.
Are brothers and sisters protective against disease? What a new twist to sibling rivalry! It is unlikely that genes are a large part of the explanation, mainly because people who migrate from places with low rates of these allergic and autoimmune diseases quickly come to have the higher rates of their new home.
A growing body of evidence suggests that the likely explanation is, as every parent knows, that bothers and sisters bring home infections. They are a veritable cesspool of viruses and bacteria. And this, it appears, is a good thing!
Why is having an infection seemingly good for children?
The explanation is all part of what is called the "hygiene hypothesis," which really should be called the "dirt hypothesis." Studies suggest that infections early in life seem to add an element of better control or regulation of the immune system. Viruses and bacteria seem to stimulate the production of special immune regulatory cells whose effect goes beyond killing the germs to dampening overactive immune responses. This is just a hypothesis and still subject to controversy, but there is considerable animal research and epidemiological data supporting it.
One way to get more mild infections is to have more siblings who bring the little germs home from day care, school, the playground or their friend's house. Just playing with many more children--that cesspool of viruses and bacteria--is another way to get more infections. Another way is not to be treated with antibiotics for every viral infection--a bad practice for a number of reasons, including breeding resistance among bacteria and maybe even increasing the chances of autoimmune diseases. The lesson: More germs early in life appear to protect against the dreaded autoimmune diseases later in life.
Scientists have theorized that smaller families--therefore fewer siblings and fewer infections early in life--have led to increases in multiple sclerosis and other autoimmune diseases. By adding all these antigerm gels, soaps, creams, tissues and wipes, we are really trying to raise our children in an antiseptic society and this may well have its own long-term consequences for increasing the rate of autoimmune diseases.
This seems like it could be a repetition of the fast-food craze of the 1960s and 1970s. So desirable at the start: novel, convenient, tasty--especially with all that salt--and slickly marketed to make us think eating fast will make us efficient and happy. But then it becomes ingrained in everyday activities where the adverse consequences, which are initially hidden, finally become magnified and obvious. Junk food has led to an epidemic of terrible nutritional habits and obesity, imposing social costs related to health care, farming, changes in seat sizes and other aspects of public facilities that far outweigh short-term corporate profits.
Instead of cleaning surfaces with antibacterial wipes and squirting antibacterial gel on children's hands, we should celebrate dirt. Encourage your children to play with other children, and get runny noses and other mild infections. It is likely to be good for them. Better a mild cold or cough than asthma, multiple sclerosis, diabetes or cancers later in life.
# posted by Gene @ 7:12 PM 
