Research raises questions about the potential health risks of canned tomatoes and other popular products

When you buy a food product, you probably don’t give much thought to the lining of the food cans, for example, or other material used for packaging. But you should be aware that some materials used to package popular foods and beverages are potentially dangerous.

For example…

Candy bars, fast food, microwave popcorn, stick butter and take-out pizza. These fatty foods are frequently packaged in materials made with a grease-resistant coating that contains perfluorooctanoic acid (PFOA), a chemical commonly used in stain- and water-resistant coatings.

Problem: Traces of PFOA invariably remain from the manufacturing process, according to an FDA study. PFOA is highly toxic, and once ingested, it remains in your body for years.

Animal studies have linked it to increased risk for liver, pancreatic and testicular cancers, birth defects and developmental problems, a weakened immune system and elevated cholesterol.

Self-defense: Avoid any foods wrapped in grease-resistant paper.

Ask restaurant personnel to put food directly in a paper bag (or to wrap it in foil first, for some foods) without the usual grease-resistant paper wrap or cardboard containers (especially when ordering egg breakfast sandwiches, French fries and chicken nuggets—all of which tested highest in PFOA levels in one study). Never heat foods in grease-resistant paper—this increases PFOA exposure.

When heating food in the microwave, I prefer covering it with waxed paper instead of plastic wrap (if it’s natural waxed paper and not chemically treated grease-resistant paper wrap). Use foil when not heating food in a microwave.

Also avoid microwave-ready popcorn—the bags have PFOA in the lining. Instead, buy loose popcorn and pop it on the stovetop in a pot with a small amount of oil or use an electric hot-air popper. If you can’t avoid grease-resistant packaging, as with store-bought butter, take it out of the wrapping immediately and store in a glass or ceramic container.

Bottled beverages and canned foods and beverages. Bisphenol A (BPA) is a component of hard, clear polycarbonate plastics that are used for bottled water and beverages and in the linings of many canned foods.

While BPA, unlike PFOA, is excreted from the body, 93% of Americans who have been tested have traces of BPA in their urine, according to a recent government analysis.

BPA’s health risks stem from its estrogen-like effects while in the body. Animal studies have linked BPA exposure to reproductive problems, including miscarriage, infertility and birth defects, as well as increased risk for breast and prostate cancers, liver damage, cardiovascular disease, diabetes and metabolic and nerve disorders.

BPA is present in many beverage bottles and five-gallon water-cooler bottles, as well as the epoxy lining of many food and beverage cans. Canned chicken soup and ravioli are the worst offenders.

Also dangerous: Canned tomatoes. That’s because tomatoes’ high acid content causes BPA to leach into the food more readily, as well as the cans of any kind of food that have been on the shelf for a long time. While no such period has been defined, scientists know that the leaching of BPA from can linings is an ongoing process while cans are in supermarkets or stored at home.

Self-defense: Limit your consumption of canned foods and beverages, substituting fresh produce or products in glass containers whenever possible. Eden Organic (888-424-3336, is one company now using BPA-free lining for most of its canned foods. Tomatoes are available in protective white enamel-lined cans with minute levels of BPA.

Finally, avoid drinking from plastic beverage bottles or five-gallon plastic water-cooler bottles with the numeral “7” in the recycling triangle on the bottom of the bottle or the letters “PC” (for polycarbonate).

For those concerned about tap-water quality, the best option is to install a water filter. (Learn about filtration systems at

Food and drinks packaged in Styrofoam. Polystyrene (found in Styrofoam food and beverage containers) has been found to leach into liquids and food—particularly in the presence of heat, fats, acid or alcohol. Polystyrene invariably contains residual traces of the chemical styrene, which has been linked to nerve damage and cancer risk.

Self-defense: Don’t drink beverages from Styrofoam cups—especially heated liquids such as coffee, tea (particularly tea with lemon, which appears to increase leaching) or hot chocolate…fatty liquids, such as milk…or alcoholic drinks.

The same goes for fatty liquids, such as olive oil or oil-based sauces and dressings, which also should not be stored in Styrofoam.

Avoid meats and other foods packaged with Styrofoam backing. When ordering take-out food, request non-Styrofoam containers. Never microwave food in Styrofoam.

Important: It may seem difficult to follow all of this advice all of the time, but you are likely to benefit from just being aware of the risks and limiting your exposure whenever possible.

Source: Olga Naidenko, PhD, a senior scientist with the Washington, DC-based Environmental Working Group,, a nonprofit, research-based organization dedicated to protecting public health and the environment. She specializes in the effects of toxic chemicals on human health.