When you crack open a can of seltzer or pop open the top of your water bottle, you're likely only thinking about your thirst. But you should probably also be thinking about the risk that comes with that gulp, because according to a new study, the bisphenol-A (BPA) that's used to make canned goods and plastic bottles causes a significant increase in blood pressure.
If you're looking for a portable thirst quencher, you might want to adopt something made of glass.
BPA has been known to to cause cancer, disrupt hormones, and prove toxic and harmful to brain development in infants and children. But we've generally assumed that the adverse health effects of BPA only become apparent after long-term, continuous exposure. Now, however, scientists have found that BPA can show its impact pretty immediately — by causing a spike in blood pressure.
In the study, published in the journal Hypertension, researchers had 60 participants drink soy milk from either a can or a glass bottle, which doesn't contain BPA, on different occasions. They found that when people drank from a can, the levels of BPA in their urine rose dramatically within two hours — and so did their blood pressure. Conversely, when the other participants drank the same beverage from glass bottles, there was no significant change in their BPA levels or blood pressure.
The urine in people who drank from two cans contained 16 times more of the chemical than if they had consumed the same amount of milk from glass bottles, so it's clearly getting into our systems.
More importantly, though, scientists found that those who drank from the cans had a increase in systolic blood pressure of 5 mmHg, while those who drank from glass bottles showed no increase.
Senior author Yun-Chul Hong said that this is concerning because high blood pressure — or hypertension — is a well-known factor for heart disease. Thus, the study suggests that BPA exposure is a risk factor for heart disease.
While the researchers didn't identify the causal mechanism behind their findings, they suspect it has to do with BPA's effect on estrogen receptors, which are involved regulating blood pressure.
It's important to note, though, that the size of the study was relatively small and only examined women (half of whom already had high blood pressure) — not exactly a perfect sample of the general population — but nonetheless, the discoveries are alarming.
Hong told the Times that he recommended people choose fresh foods and glass bottles over cans and plastic containers. He also urged manufacturers "to develop and use healthy alternatives to BPA for the inner lining of can containers."
Now, these findings are not a reason to panic. One swig from a plastic water bottle is probably not going to give you a heart attack. But these scientists have clearly identified an issue here that we could make an effort to avoid — by drinking from BPA-free containers. So while you may think drinking from a mason jar is too kitschy for you, we think you can pull it off.