Bromine Bullies Iodine

When life gets comfortable, humans have a tendency to take things for granted.  “Ooh, yeah, I travel this route every day, so I know that light will change in about three more seconds.  Oops!  Not that time.”  “There’s hardly any traffic on my street, so I don’t have to look both ways before crossing.”  Mostly.  “That agency would never allow this stuff in our food.”  Maybe.  The stuff is bromine (bro-meen), one of the halogen elements that keeps company with fluorine, chlorine, and iodine.  It also hangs with astatine, but that’s radioactive and unavailable in nature.  Of these, iodine is the one we want…and need.

But bromine is the one occasionally forced down the throat, figuratively and literally.  Bromine’s utility covers quite a range.  In the form of methyl bromide and ethylene dibromide it’s a fumigant.  It also appears in cleaning agents, dyes, photographic chemicals, water (sewage) sanitation, pharmaceuticals, flame retardants, and in the bleaching of fabrics.  If you’re not a reader of food ingredient labels, you’ll never know it’s in some of your food as well, either as bromated flour, brominated vegetable oil, or in another form.

As a flame retardant called Tris, bromine was used in children’s clothing, especially sleepwear, until the Consumer Product Safety Commission pulled it from the market in the late 70’s because of its potentially carcinogenic activity.  Not only was skin contact an issue, but also the “mouthing” that is common among toddlers.  (U.S. CPSC, 1977)  It’s not likely you have 35-year-old kids’ PJ’s around, but government acknowledgement that a substance can make us sick is worthy of attention.   If you have youngsters at home, it still might pay to read the pajamas’ label to check for flame resistance.  You might call the manufacturer to find out what chemical is used.  Although some fibers are naturally resistant to flame, many synthetics are not, including the acetates and polyesters.  Still, it is deemed prudent to launder children’s sleepwear more than once prior to first use.  To satisfy regulations, sleepwear has to be chemically treated to resist flame or be tight-fitting enough to discourage it.

Bromine has no necessary function in the body.  Substantial exposure to it can cause iodine deficiency, which will ultimately wreak havoc with the thyroid and every tissue in the body.  Prior to the year 2000, many of us had been exposed to considerable amounts of bromine from the pesticides used on produce and grains.  Its use is now restricted because of the dangers it poses to applicators, but it is still used.  (Do you like CA strawberries?)  However, as a fire retardant, it can be found in the plastics used in televisions and computers, in upholstery and carpeting  (as part of that new-car smell), in baked goods, and, of all places, in citrus-flavored beverages, including sodas and sports drinks.

Studies in Sweden have found measureable amounts of brominated substances in wildlife, and have noted that the thyroid glands of similarly treated laboratory animals suffered adverse effects. They added that the chemicals bind to red blood cells, which now entail the liver and kidneys.  (Darnerud, 2003)  A concern is that bromine behaves in a manner parallel to chlorine and iodine, two ions necessary to human metabolism.  Czech investigators realized that high levels of bromine can affect the body in two ways:  they can decrease iodine accumulation or increase iodine excretion by the kidneys.  In either case, the pool of iodine in the thyroid is diminished.  To an expectant or nursing mother, this is a legitimate concern.  (Pavelka, 2004)  Iodine deficiency is recognized as the most preventable cause of neonate mental retardation, developmental delay, and primary hypothyroidism.  (Patrick, 2008)  (DeLange, 2001)

A recent explosion of interest accompanied announcements that some soft drinks—mostly the citrus-flavored—have been adulterated with bromine in the form of brominated vegetable oil (BVO).  We wondered why soybean or corn oil would be brominated in the first place, and learned that it helps the oil to emulsify the beverage so it remains cloudy and keeps the flavoring suspended in the liquid.  Oil (citrus oils in this case) floats on water, but bromination makes the oil equally dense as water.  The U.S. Code of Federal Regulations restricts the addition of BVO as a food additive, but nonetheless allows its use.  That means that dosage makes the difference, just as being hit by a truck moving at twenty miles an hour differs from one moving at fifty.  It seems incongruous that bromine is listed in the Hazardous Substances Data Bank of the National Library of Medicine, yet is a food additive in the Federal Code.  (  People who have overdone the BVO in soft drinks have experienced headache, fatigue, ataxia, and memory loss.  (Horowitz, 1997)  Could that happen because bromine pushes iodine out?  Of all the halogens, iodine is the least reactive and the easiest to displace, despite being the heaviest element in the body, where it is distributed in mammary glands, the eyes, the gastric mucosa, and the salivary glands.

Long after ingestion, traces of BVO remain in tissue, and it likes to occupy space in the thyroid that belongs to iodine.  A hundred years ago, bromine, in the form of potassium bromide, was used as a sedative, but its application in that area has been limited to epilepsy, in which case it still interrupts iodine’s role in thyroid hormone synthesis.  (Li, 2011)  Despite a poor reputation, bromine compounds are used by the baking industry to improve the gluten development of flour.  Once upon a time flour was naturally aged through exposure to air, allowing it to oxidize on its own and to develop the building blocks it needs to bridge gluten molecules and to create a stronger dough.  Potassium bromate is used to hasten the process.  Along the way, it whitens the flour, which seems to make it a more acceptable commodity.  Oddly, potassium iodate is also an oxidizing agent.

Even stranger is that potassium bromate has been banned in the European Union, Canada, Nigeria, Brazil, Peru, China, and Sri Lanka, but not in the United States.  California, though, has required a warning label on bags of bromated flour.  Now that we have fire retardant soda and flour, don’t you feel safer?  Soda has never been a dietary winner, but now it’s even less so.  By the way, theobromine in chocolate contains no bromine.

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