Does Chlorinated Water Kill Your Microbiome?
I was reading the latest book from Dr. David Perlmutter, Grain Maker, where he makes the statement, “Chemicals, such as chlorine, that are added to many sources of water, to kill bad bacteria will also kill good bacteria, probiotic bacteria.”
Since I’ve been drinking chlorinated water my entire life, as most Americans have, I was disturbed by this statement so I thought I’d do some research.
First off, Dr. Perlmutter doesn’t offer any scientific research for this statement. I wish he had sited some sources.
On the other hand, it does seem to make some sense. I’ve learned from practical experience that putting gold fish in a bowl filled with tap water will kill them fairly quickly. My logic is, if it will kill a gold fish, wouldn’t tap water also kill bacteria in your gut?
In 1998, the magazine, Scientific American, asked the question, “How does chlorine added to drinking water kill bacteria and other harmful organisms? Why doesn’t it harm us?” Their answer back then was, “Food in our stomachs and the materials normally present in the intestinal tract quickly neutralize the chlorine. So chlorine concentrations along cell membranes in the gastrointestinal tract are probably too low to cause injury.”
I did find some interesting research as to how tap water affects garden plants and lawn. Their main conclusion was, “Researchers have found that chlorinated drinking water may kill a number of microorganisms in soil or a compost pile. However, their reproduction rate is so rapid that populations rebound in a short time.”
In the St. Louis area, they add ammonia to the chlorine to keep it more stable – they call this chloramination.
The EPA has lots of informaion on chloramines. It has been used for decades in some communities. Here is the link. Chloramines in Drinking Water.
Josh Harkinson did an article for Mother Jones which includes this quote, “Chlorination has done tremendous good, so the default is to continue as is,” Martin Blaser, the director of the Human Microbiome Project, told me, “but whether or not there are subtler effects needs to be studied.”
A friend of mine in the field told me, “Specifically about chloramine, it seems that many water districts have switched from chlorine to chloramine because (1) it has a longer-lasting disinfection effect which keeps down bacterial growth in holding tanks and pipes, and (2) it has fewer toxic disinfection byproducts than chlorine. Chloramine is considered safe (at <4 mg/L) by the EPA. I doubt that chloramine would kill off bacteria in your body and/or probiotics at the low levels present in drinking water – it can be broken down (metabolized) by your saliva and leave your body in your urine. But I haven’t seen any specific scientific studies on this.”
Thanks to J for pointing me to the SFWater.org site which has a lot of information on chloramines.
To summarize the SFWater.org information – Water with chloramines is safe to drink.
If you still decide to remove the chloramines, then for an investment of $23 plus the filter cost, a Brita pitcher filter is an easy way to remove the chloramines..
Here are some other resources.
- Pass the Microbes Please – very interesting story.
- Science Magazine – microbiome and obesity
- Mother Jones Story
- Martin Blaser – Youtube video