Study looks at health impact of bisphenol A (ZT)

Sept. 20, 2008  from MayoClinic

By Jennifer Nelson, M.S., R.D. and Katherine Zeratsky, R.D.

5 comments posted

• Read comments
• Post a comment

An important article in the Sept. 17 issue of the Journal of the American Medical Association discusses the health effects of the chemical bisphenol A. What is this compound and what are its effects? What might happen as a result of this study?

Bisphenol A is a chemical in plastics. It is widely found in the lining of food containers, plastic bottles, compact discs, carbonless paper, and many medical devices. It also is used to coat metal products (food cans and bottle tops), and even water supply lines. Some dental sealants also contain this ingredient.

Animal studies done in the 1980s and '90s identified that low doses have adverse effects on the brain, reproductive system, and metabolic processes related to insulin balance and liver function. It may also be related to cancer or even obesity and heart disease. Although it is not immediately lethal, studies show that greatest sensitivity to bisphenol A occurs during periods of early development and that the substance accumulates over time in the body and environment.

Because of this, the greatest concern is during fetal development, in infancy — and then over the remaining life cycle. Such animal studies have called into question the acceptable daily intake levels set by the U.S. Food and Drug Administration and the Environmental Protection Agency.

For many reasons, governmental protection agencies require an accumulation of both animal and human studies using accepted research and measurement techniques to link chemical compounds to adverse health effects. It's looking like this is beginning to happen. The JAMA study by Lang and colleagues is the first large-scale, population-based human study that links bisphenol A with some of the most common diseases we face: heart disease, type 2 diabetes, and liver enzyme abnormalities.

It's important to understand that this epidemiologic study points only to the association of bisphenol A and health risk — it cannot be inferred that bisphenol A causes such problems.

So what can we do in the meantime? I want to direct your attention to MayoClinic.com's April 22, 2008, "Pregnancy and you" blog: "Try glass when shopping for baby bottles." My colleague Mary Murry gets you and your infant off to a great start.

The National Institute of Environmental Health Sciences recommends that you can also reduce exposure to you and your family by:

• Limiting canned items — especially those with linings. These include mostly acidic items like canned tomato sauces and canned pasta items. Buy those in glass. Better yet, buy fresh.
• Avoiding plastic bottles that are designed to be used numerous times — like plastic sports bottles, and even those refillable multi-gallon jugs you take to the store. The National Institute directs you to also avoid plastic containers with the number 7 listed on them — usually encircled with the recycle symbol.
• Not microwaving plastic food containers and not putting hot foods into them. Likewise, don't wash these types of containers in the dishwasher. Heat, detergents and scrubbing can break down bisphenol A and increase exposure. Instead opt for glass or other non-plastic cooking and serving containers.

Some health care providers are also recommending using powdered infant formula instead of ready made. Liquid formulas have more bisphenol A. Ask your health care provider to help you make this transition.

Canada has recently declared bisphenol A to be a toxic chemical and is implementing actions to limit use and therefore exposure to humans, and the environment — and by inference, in our whole food supply. It is hoped that the results of this new study will prompt our government and others to at least re-evaluate the acceptable daily intake levels, fund the necessary studies that can determine if bisphenol A causes ill health, and be vigilant in protecting us from ultimately ourselves.

With concern for our health,

Jennifer