Is this dangerous for our babies?

The estrogen-mimicking chemical bisphenol A is widely found in baby food sold in glass jars in Canada, according to a survey conducted by Health Canada that found the compound in about 84 percent of samples.

"The results of this survey clearly indicate that exposure to BPA through the consumption of jarred baby food products would be extremely low" with the amounts "not expected to pose a health risk to the consumer," Health Canada officials said.

Is this something to worry about? Pediatrician Dr. Cara Natterson says:

Here's my bottom line: This isn't something to lose sleep over, but it isn't something to blow off, either.

BPA is a chemical that can potentially cause disease. It has been accused (among other things) of causing uterine fibroids, endometriosis, breast cancer, lowering sperm count, and increasing the risk of prostate cancer. Many challenge these accusations because the studies that document these effects are small or have not been repeated. But what most people agree upon is that BPA is an endocrine disruptor: a chemical that can affect the way hormones work in some people's bodies. For this reason, if it can be avoided, it probably should be.

Canada has been on the front lines of the war against BPA. In April 2008, the Canadian government classified BPA as "toxic" to human health and the environment. One of the reasons why is that BPA can imitate the actions of estrogen and, many times, BPA concentrations are far higher than normal estrogen concentrations found in the body (parts per billion versus parts per trillion). But this accusation -- that there is more BPA in many products sold on the market than there is estrogen in our own bodies -- isn't entirely fair. BPA is not estrogen, it just looks like estrogen. And according to most studies, the biological effects of BPA are nowhere near those of estrogen: it is not nearly as potent as the natural hormone, and oftentimes it is completely impotent.

So while it's fair to look for these chemicals in our containers and our foods, don't overreact. There is always going to be another chemical or another "discovery" around the corner that makes us worry about what we are putting into our bodies or our children's bodies. We need to be asking the questions; scientists need to be doing the research. But wait until the data dictates -- don't jump every time there is a new study published. If it turns out that baby foods in glass jars are repeatedly found to have BPA, then the source of the BPA should be removed. Until then, keep your cool. Maybe, though, it's a good argument for trying to find the time to mash your own bananas at home?

Dr. Cara Natterson, a graduate of Harvard University and the Johns Hopkins School of Medicine, and author of "Your Toddler: Head To Toe," is a pediatrician and mother of 2. She is working on her forthcoming book, "Dangerous or Safe?"