There are many clear-cut studies out there and even older ones with amazing information that is worth sharing. In this fascinating study, it is clearly shown how even a single intake of BPA (from a beverage can of normal size) can cause a rapid and significant increase in blood pressure. The connection between BPA and hypertension is known for some time; but this study was particularly provocative in showing the magnitude of the effect. I encourage you to click on these links and see the data for yourself.
Bottom line: “The study found that when people drank soy milk from a can, the level of BPA in their urine rose dramatically within two hours – and so did their blood pressure. But on days when they drank the exact same beverage from glass bottles, which don’t use BPA linings, there was no significant change in their BPA levels or their blood pressure.” A very well-done study with clear results.
There are many endocrine disruptors (aka estrogen mimickers) that we encounter in modern society. This collection of exogenous (or xeno-) estrogens can have a dramatic effect on our natural hormone balance (or lack of it). One of most potent and pervasive endocrine disruptors is bisphenol-A (aka BPA), a common ingredient in plastics used to line metal food and beverage cans to prevent corrosion.
BPA is also used to make many cash register receipts slippery. When we hold the receipts, we absorb the BPA. If we’ve just used hand sanitizer, this effect is significantly greater. If the can lining includes BPA, it dissolves into the food, and we absorb it during consumption. Unfortunately, not rocket science. And the cumulative effect can be quite significant. In the face of much negative press about BPA in this light, many manufacturers are turning to other plastics with different names that have – unfortunately – the same or worse endocrine-disrupting properties.
We can put a lot of effort in eating more whole, natural, unprocessed foods. But it’s important to consider the container too. Substances in containers leach into food and beverages. Especially with heat and sustained storage.
I recommend that you choose fresh foods and glass bottles over cans and plastic containers. I do not recommend microwaving in any kind of plastic (a glass bowl topped by a paper towel works just fine). Unless a product certifies its cans are BPA-free, you can safely assume they do include BPA (it’s still an industry-standard practice). The same applies to organic food brands. Contamination of BPA in the food is also likely to be enhanced in canned acidic foods (e.g. tomatoes or foods including vinegar).
Think of that next time you are in the supermarket and chose glass containers.