Q: Other than hydrogenated oils and high-fructose corn syrup, what one ingredient should I avoid?

A: Industrial trans fats found in hydrogenated oils and added sugars-not just high-fructose corn syrup-are definitely the top two ingredients that you should minimize and avoid. They are really both in a class of their own, but what should you shun to round out the top three? Bisphenol-a, also known as BPA.

I first learned about the negative health effects of BPA about eight years ago in an interview I conducted with John Williams, Ph.D. He told stories about the extreme estrogenic effects on animals whose environments had been exposed to waste spills and dumping that involved large amounts of BPA. The missing link for me at that time was the human connection and the effects of BPA on people.

However, in the last year there have been almost 60 research studies published looking at the implications of BPA on human health. These findings and more were summarized in a recent review published in the journal Reproductive Toxicology. The authors found that BPA exposure has been associated with increased risk of:

• miscarriage

• premature delivery

• reduced male sexual function

• polycystic ovary syndrome (PCOS)

• altered thyroid hormone concentrations

• blunted immune function

• type-2 diabetes

• cardiovascular disease

• altered liver function

• obesity

• oxidative stress and inflammation

Why Is BPA Bad?

BPA is an endocrine-disrupting hormone-essentially it is a chemical that acts to disrupt our body's normal hormonal function. It wreaks havoc in a variety of ways from acting like estrogen, blocking estrogen's action, binding to thyroid receptors and thus impairing thyroid function, and more.

I don't see any other food or ingredient in our food supply having these sorts of effects. Fortunately due to consumer outcry, BPA has been essentially eradicated from the plastics sold for use as water bottles and food containers. Just five years ago when my wife and I had our first children (we had twins), finding BPA-free bottles was extremely difficult and expensive; as of July 2012, however, the FDA has banned its use in baby bottles and sippy cups.

If BPA from food and water containers are no longer an issue, where are you getting exposed to BPA? Unfortunately six million tons of BPA are produced each year, so it is everywhere. It is used as a coating on receipts, although unless you are a legitimate shopaholic the transdermal transfer of BPA from receipts is most likely minimal. BPA is also found in dust around your house-yes, dust; that is how ubiquitous this toxin is in our environment. As a result, exposure via food is probably not the biggest source. But you still can minimize exposure and accumulation of BPA. Here are two things to focus on.

1. Be smart about cans. BPA is to coat the inside of cans. Avoiding canned vegetables and opting for fresh or frozen shouldn't be too hard of a switch. Buying dried beans instead of canned beans will not only reduce your exposure to BPA, but it is more cost effective and it makes controlling your sodium intake easier. When buying tomato products, look for those sold in glass jars whenever possible. While there are BPA-free cans for beans, they are much less common for tomato products, as the acidity of tomatoes makes the protective coating of BPA an important component to protect against the metal of the cans.

2. Lose weight. BPA is a fat-soluble chemical that can be accumulated in your fat cells. So while you may be doing your best to keep your house BPA-dust-free while not keeping your foods in potentially BPA-containing plastics, the bad news is that you might be the biggest storage vessel of BPA in your life. The good news is that your body can readily excrete BPA via urine. Once you liberate it from your fat cells, you body can get rid of it. Losing weight and staying lean could be one of the best ways to reduce chronic your exposure and accumulation of BPA.

Fortunately the health hazards associated with BPA are starting to reach the people who have the power to regulate the omnipresence of such a chemical. The FDA has recently labeled BPA a "chemical of concern," so hopefully there will be more research and regulation surrounding BPA in the near future. In the meantime, be wearing of your canned foods and stay lean.