Q: I am wondering if acid in tomato juice would interact with BPA in cans to help it leach more into the food. Also, would it leach more the longer you kept the can?

A: If you consume canned soups, beans and soft drinks, organic or not, you also may be swallowing residues of a controversial chemical called Bisphenol A (BPA) that can leak out of the can linings into your food. Nearly all can liners contain BPA, but the levels that leach into food are well below the safety thresholds set by the Environmental Protection Agency (EPA) whose figures suggest that the chemical is completely safe unless you ingest 1,300 pounds of canned and bottled food daily.

However, many scientists and consumers are skeptical about BPA’s safety, and, honestly, there is very little evidence from human studies on which to base either side of the argument, but my philosophy is never take a risk if there’s a way to avoid it. Canned foods that are acid (tomatoes, tomato-based soups, citrus products, and acidic beverages like cokes) and canned alcoholic beverages, since acids and alcohols can exacerbate the leaching of BPA. Try to find these items in glass jars.

Choose soups, milk and soy milk packaged in cardboard “brick” cartons, by Tetra Pak and SIG Combibloc, which are made of safer layers of aluminum and polyethylene (#2) and also recyclable. Choose canned foods from makers who don’t use BPA, such as Eden Foods (www.edenfoods.com), which sells certified organic canned beans and other foods.

Dr. Brent Ridge is the health expert for Martha Stewart Living Omnimedia. You can call and ask him a question live every Tuesday at 2 p.m. Eastern on Sirius Satellite Radio, Channel 112 (1.866.675.6675). You can also follow along as he learns to grow his own food and raise goats on his farm in upstate New York by visiting www.beekman1802.com.

Got a health question for Dr. Brent? E-mail him at drbrent@care2.com.