One of the most dangerous compounds in most fruit and vegetable juices you buy in plastic bottles is a chemical known as bisphenol-A, or BPA. You won't ever see it listed on the label because it's not added to the juice. It's in the plastic bottle itself.
BPA is one of the chemicals used to make plastics hard. It's released from the plastic back into the juice when plastic is heated. This could happen if the juice had been transported from the factory to the store in an hot train car or in a truck that did not have air conditioning, if the pallet of juice bottles was left out on a hot loading dock or if left your purchases in a hot car or a hot closet.
This plasticizer leaches out of the bottle more quickly if the juice inside it is acidic. And it's also released by microwaving.
BPA released from plastics is not just a problem with juice, although one of the worst products for BPA contamination is a line of children's beverages called JuicyJuice. BPA is found in frozen dinner containers, cookie cartons, “cardboard” containers, milk containers, canned foods, DVDs, computer keyboards, upholstery, clothing, and even in some capsules used for medications. Nearly every human being is exposed to BPA nearly all the time. The problem with BPA is that it can imitate estrogen, and it can also make you fat.
BPA is a member of a category of chemicals known as xenoestrogens. These are chemicals that aren't estrogen, but that can act in the body in the same manner as estrogen. All over the world, more and more adult men have lower and lower sperm counts. All over the world, more and more girls are experiencing their first periods at younger and younger ages. The Endocrine Society has documented cases of girls who have been exposed to large amounts of BPA who started menstruating at the age of 6.
BPA isn't just a xenoestrogen. It also is a peroxisome proliferator receptor agonist. What that means is that BPA helps insulin do its job. Insulin transports sugar out of the bloodstream, but it also helps store fat. Your fat cells don't store fat if you are eating so little that they start burning fat, but it you do overeat, even a little bit, BPA makes sure that the fat is stored, preferentially in fat pads over your belly and buttocks.
If it sounds like plastic bottles make your butt fat, that's more or less the right idea. Drinking juices or any other beverages that have been stored in plastic containers, especially if the liquid has been exposed to heat, just isn't a healthy thing to do.
So what's the answer? Do you have to give up buying juice at the store?
Cardboard containers can also release BPA, but usually not as much. If you have to buy store-bought juice, get it in cardboard containers. Juice that has been bottled at the store the same day it is squeezed it also OK even if it is in plastic bottles.
But by far the best way to avoid plasticizers in your juice to make the juice yourself. Home-squeezed juice is free of plastic chemicals that can wreck your health, and it has maximum taste and flavor. Juicing at home is always the healthiest way to enjoy fruit and vegetable juice.