Saturday, October 24, 2009

Editorial: Is your cheese drugged?

A few months ago, a short article in Prevention Magazine mentioned how baby carrots are rinsed in chlorine to kill bacteria like salmonella and E. coli, which can cause illness.  The FDA recommends chlorine rinses (or other sanitizers) for most precut produce, including frozen veggies and fruit salad.  Cornell Professor Randy Worobo was mentioned in the article, saying that there's no reason to stop eating the baby carrots.

The article caught my eye because I'm fascinated by what I do *not* know about what I'm eating -- and the lengths I have to go to find out.  Last year, I noticed the ingredient list on a package of shredded cheese and was surprised to see "natamycin."  

Huh?  I thought.  I'm eating my cheese with a side of antibiotics?  I've known about drugs used in livestock agriculture for a long time, but I didn't know that I was ingesting them directly from my own food.  After some web searching, I found that natamycin is natural extract from bacteria and it prevents the growth of fungus. 

So I called up Randy Worobo to ask some questions about natamycin.  Why is it in there? He said it's because the surface of cheese tends to get a little moldy when exposed to air, and shredded cheese has a lot of surface area.  In contrast, blocks of cheese can be vacuum-sealed to prevent mold growth, whereas shredded cheese cannot.

The second question I asked: why doesn't the compound appear specifically as a drug on the ingredient list?  (I was thinking about the standard labels that appear on over-the-counter drugs).  He explained that compounds are only considered drugs when highly purified. Since natamycin is a natural extract from bacteria, it doesn't have to be labeled as a drug. Interestingly, however, natamycin is used as a drug (often in the form of cream) to treat fungal infections in people.

Natamycin is widely considered safe (and it is used instead of chemical preservatives). But I still wonder: is it truly necessary? When mass quantities are used in industrial food prep, does it leach into our environment? 

I'm still scratching my head.


  1. Nice investigative reporting! I was always a little suspicious of pre-shredded cheese, but not suspicious enough to check the label.
    It's only a matter of time before cheese mold develops resistance to this antibiotic, and after that our medical-grade drug will be useless.

  2. This is my first time on your blog and it's great. It will be regular reading. The more questions asked the better. It seems anything can be labeled as safe for a processed food. There are plenty of biproducts to go around to fill and preserve the plastic food produced in a lab. Keep up the good work!!

  3. Glad you found this info interesting, Joe and Merry!