Recently groups such as the Natural Resources Defense Council, the Union of Concerned Scientists and the American Academy of Pediatrics have made petitions to the FDA requesting that they reevaluate the use of low-dose antibiotics in animal feed.
In 2009 humans consumed about 7 million pounds of antibiotics, animals 28 million pounds.
While perusing this list I cam upon ionophores. Next to tetracycline ionophores are the second most common compound used in animal feed. Now I've been around a while and most of the rest of the things on the list I have at least heard of before - but not ionophores.
Every hear of them?
No, I thought not.
So just what are these compounds?
Ionophores are compounds that affect how substances pass through the celluar membranes of microbes. So, for example, some might block the passage of sodium ions through a cell membrane. If the microbe requires sodium to live then the ionophore will cause it to die because it is unable to process sodium ions.
So specific ionophores are specific to kinds of ions. And specific ions are used by particular bacteria, for example, in the gut of cattle.
Use of ionophores in animal feed can also cause cattle to produce less methane by changing how they digest their food and how that food is absorbed into their bodies. And, more importantly, according to this "feeding of ionophores to cattle decreases the feed needed for growth and increases feed efficiency." (These sorts of statements always bring to mind the old adage "you can't get something for nothing.")
The actual effect is that these compounds delay the processing of the food consumed until after the stomach leaving the work to be done by the intestines instead. These compounds are also apparently only safe for a small number of mammals, e.g., cattle and chickens. Their use is detrimental to horses, dogs, and other common farm animals.
Ionophores are not antibiotics per se hence the FDA does require meat sold from animals feed with ionophores to be labeled as containing antibiotics.
Ionophores are not used for humans do to their potent cardiovascular effects (see this). I cannot find a lot of detail on exactly why but it seems that these compounds can damage cardiac and skeletal muscles.
Groups such as those I mentioned above are starting to catch on that these things are probably not a good idea and have asked the FDA to reevaluate the use of these drugs as well as antibiotics.
The FDA, however, is resisting, claiming that its "too time consuming" to review the use of antibiotics in animal feed (see this).
Imagine - a heath care issue that affects literally everyone who eats meat or uses meat products in some way - and the FDA finds it "too time consuming" to look into it.
Today about one in twenty patients who enter a hospital acquire a potentially deadly bacterial infection - on that's resistant to antibiotics - exactly the problem caused by feeding antibiotics to animals.
And the FDA finds it "too time consuming" to bother with.
Perhaps they will take it more seriously after more people die on their watch.