Plastics - A Heated Debate

from The Food Coach

Plastic is everywhere, there's no denying it. Water bottles, food storage, toys, takeaway containers, cling wrap, the list is endless. A useful invention, granted, but can too much of a good thing prove harmful? In the case of plastics, it seems so. Certain chemicals such as Bisphenol-A have been found to cause danger to humans, with a recent US Federal Report released acknowledging the potential health problems, in particular for children.

Bisphenol-A, known as BPA, is most commonly used in plastic water bottles, baby bottles, linings of food and drink containers and cans and also in dental amalgams. The problem is that BPA doesn't remain inside the plastic; rather it migrates into food, water and even the mouths of people who've recently had a dental cavity sealed. Microwaving or heating the plastic causes the chemical to further leach out of the plastic and into food or drink, and the softer the plastic is, the higher the transference of chemicals becomes.

According to some scientists, BPA imitates the body's naturally occurring oestrogen, with studies linking the chemical to breast and prostate cancer, behavioral changes and early sexual development in rats.

"There's no doubt (BPA) can behave as oestrogen mimics," said William Trogler, a UCSD chemistry professor. "The issue is the level of exposure, in particular what people actually experience. Is the level significant or not?"

A recent study by the University of Cincinnati highlighted this fact when researchers tested polycarbonate baby bottles by exposing them to boiling water (supposed to simulate repeated use and washing) and found they released 55 times more BPA than bottles exposed only to hot water.

The plastic industry disagrees, with the website bisphenol-a.org stating that levels of BPA in plastics are only harmful if a person ingests more than 590 kilograms of canned and bottled food daily. If higher doses are safe, then lower doses must also be harmless, right? Wrong.

In the case of hormone disruption, different doses of BPA can stimulate or suppress various genes, explains Frederick vom Saal, Ph.D., a developmental biologist at the University of Missouri. "The studies didn't look at the low doses that are now proving to cause a myriad of harmful effects in animals, including chromosomal damage in female egg cells and an increase in embryonic death in mice." A follow-up to this is a study that showed a relationship between BPA blood levels and miscarriages in Japanese women, with Japanese scientists also detecting BPA in the amniotic fluid and umbilical cords of unborn children. In 2004, the US Centers for Disease Control and Prevention (CDC) found levels of BPA in 95 per cent of urine samples tested.

Bisphenol-A isn't the only plastic ingredient under suspicion. Phthalates (pronounced "thay-lates") are a group of compounds used to make plastic soft and flexible, and can be found in toys, cosmetics and the capsules of some medicines. Research on animals has shown that phthalates can lead to hormone imbalance which is linked to organ damage, cancer and developmental abnormalities.

Major organisations and companies have taken action, which implies that the plastics debate has some weight behind it. Most recently, the Canadian government has classified BPA as toxic, and the European Union has banned the use of these chemicals in children's products, with the state of California following suit. Bottle manufacturer Nalgene declared they will no longer produce bottles containing Bisphenol-A, and major US retail chains Wal-Mart and Target announced plans to switch to selling only BPA-free baby products.


Despite the best efforts, it's difficult to avoid plastic entirely, but you can minimise risk and exposure:


Don't heat foods in plastic containers in the microwave, regardless of whether they state "microwaveable safe". Glass containers such as Pyrex dishes are a much safer alternative and will last longer, so are therefore cheaper in the long term.

Likewise, never cover foods with cling wrap and then place in the microwave, especially if the plastic is likely to come into contact with the food.

Store foods, liquids and perishables in glass or ceramic containers, especially foods that are hot or are likely to be heated.

Check any plastic containers or Tupperware in the cupboards, and dispose of those that are scratched or cracked.

Avoid reusing takeaway plastic containers - help the environment by recycling them instead. If you get a coffee every morning, take your own reusable thermos mug along to the café.

Buy products labelled BPA-free, and avoid those with the recycling numbers 3, 6 or 7 printed on the underside.

Somewhere on most plastic containers is a recycling symbol and a number in a triangle to indicate the type of plastic used. In general, only containers marked 1 or 2 are easily recycled. Consult the following chart to see if the plastic you're using is safe:

Plastic Number Where it's found and is it safe?
1. Polyethylene terephthalate ethylene (PET or PETE) is used in disposable water, juice and soda bottles. It presents no known health hazards, particularly if used only once.
2. High density polyethylene (HDPE) is used in opaque milk jugs, bleach and shampoo bottles, and some plastic bags. No known health hazards.
3. Polyvinyl chloride (PVC or V) is used in cling wrap, some squeeze bottles, peanut butter jars and window-cleaner bottles. Many chemicals are added to PVC to make it soft and flexible. Some of these compounds are suspected toxins or endocrine disrupters.
4. Low-density polyethylene (LDPE) is used in grocery bags, most plastic wraps and some bottles. No known health hazards.
5. Polypropylene (PP) is used in longer-lived plastics, straws and some baby bottles. No known health hazards.
6. Polystyrene (PS) is used in egg cartons, carryout containers, disposable cups and opaque plastic cutlery. It is made from styrene, a suspected carcinogen, and other chemicals believed to be endocrine disrupters.
7. All other plastic resins, including polycarbonates (PC), which are used in clear baby bottles, 5-gallon water bottles, food can linings and dental fillings. Polycarbonates contain BPA, which has been linked to a variety of maladies.


Reheating - the safe way

By Amy Pongrass, Nutritionist

Reheating foods doesn't always have to involve a microwave - use the oven on a low setting for meals, and the stovetop for leftover soups. If you need to reheat a grain, put it in a ceramic or porcelain bowl and place in a saucepan. Fill with enough water to come half way up the side of the bowl, cover and gently steam. Otherwise you can place the grain in a sieve and pour boiling water over it to refresh and quickly heat.