It’s Friday night. You grab a can of beer from the fridge and sit back on the couch. You pop the tab and guzzle the first mouthful of … BPA, a potentially carcinogenic chemical.
BPA, otherwise known as bisphenol A, is a chemical used in the manufacturing of plastic. In the case of cans, it helps create a protective barrier between the aluminum in the can and the liquid inside.
Unfortunately, beer and soda companies are still coating their cans with BPA even though BPA is known to have endocrine disrupting effects.
Why would they do this even though research definitively shows BPA is a harmful chemical?
Beer has an acidity of about four on the pH scale (one being gastric acid and seven being distilled water). For reference, pineapple1 has a pH of about 3.3 to 4. If beer cans didn’t have a protective layer lining the aluminum, the beer would eat away at the aluminum and develop a metallic taste.
At this time, using an epoxy containing BPA is the most commercially viable way of packaging canned beer.
Canned beer isn’t the only source of BPA. Virtually all canned foods and beverages contain a BPA epoxy to protect the integrity of the can.
Think back to all the food you ate in the last twenty-four hours. How many foods did you eat from a can? Soup? Fish? Beer? Soda?
Canned food is such a large part of our life that we don’t even think about it. However, hopefully after reading this article you’re more aware of the chemicals you’re putting into your body and the hidden health effects of canned foods.
Keep reading to find out why you want to avoid BPA and how you can take steps to avoid it.
BPA was first manufactured in 1891 by Alexander P. Dianin, but it didn’t become commercially ubiquitous until after World War I2.
In 1932, a British biochemist named Charles Dodds3 discovered BPA has estrogenic properties. Dodds was curious if synthetic hormones could affect hormone production in humans. He later developed a more stable form of synthetic estrogen called diethylstilbestrol (DES).
DES would later go on to be prescribed to women for pregnancy and menstruation problems. However, in 1971 the drug was banned for causing a rare form of vaginal cancer.
BPA and DES have similar structures. In fact, they’re more similar to each other than to estrogen found in the human body4. Even though BPA was never prescribed as a drug, it would find its future in manufacturing.
Sixty years after the discovery of BPA, chemists discovered that when long chains of BPA link together, they can be used to form polycarbonate plastics. American and Swiss chemists used these polycarbonate plastics to create epoxy resins from BPA as a covering for the aluminum in your beer cans. By the end of the 1980s, BPA was being used in DVDs, water bottles, baby bottles and hospital equipment.
BPA is still used in plastic packaging around food and the coatings of cans and jars5.
A marine biologist named Rachel Carson released a book in 1962 titled Silent Spring. Her book brought attention to the possibility of various man-made chemicals in our environment having detrimental effects on our health. Carson postulated that even low dosages of some chemicals could have powerful effects on animals and that the effects of various chemicals could become compounded4. Over the next 29 years after the release of her book, researchers began further examining the effects of environmental toxins collectedly known as endocrine disrupters. Evidence that these chemicals could impair human health grew until the year 1991.
At this time, scientists came together at the Wingspread Conference to publicly present the endocrine disputing hypothesis6. Since then, research about the endocrine disrupting and carcinogenic effects of BPA have been repeatedly proven.
In 2008, the Canadian government announced that it would declare BPA toxic. Later in that same year, the FDA released an assessment confirming that they also considered BPA to be toxic and carcinogenic.
History of Canned Foods
Canned foods have a long history dating back hundreds of years. Long before the commercial usages of aluminum, in the 1700s, people used corked and sealed glass jars to increase the amount of time food could be preserved.
By the 1800s improved technology allowed the mass distribution of tin cans. This invention made transporting preserved goods much more efficient since the cans were virtually indestructible (too bad the can opener wasn’t invented for another 40 years).
By the late 1800s, cans were prolific in grocery stores, but they still weren’t used for beer.
The beer can didn’t come into existence until after the prohibition. In 1935, in Richmond, Virginia, Krueger used cans for a 3.2% beer called “Kruger’s Special Beer7.” Although there was resistance to canned beer at first, by the second world war, millions of cans were being shipped overseas to soldiers.
Why You Should Avoid BPA
Exposure to BPA has become an increasingly common occurrence in our lives. In 2008, worldwide production was estimated to be 5.2 million tons. BPA is a component of healthcare equipment, dental composites, contacts, lenses in glasses, toys, computer drives and window frames5.
How safe is BPA?
Research shows that even small amounts of BPA exposure can have health consequences. The debate about the level of safety of consuming products containing BPA continues. BPA can enter our body either through our skin, lungs, or digestive system. Food products are by far the highest source of BPA8.
Both the lining of cans and plastic wraps contain BPA. Research shows that when you heat food products containing BPA, the amount of BPA that leaks into the food increases (just another reason not to drink warm beer)9.
Health Complications of BPA Exposure
When BPA enters your body, it interacts with estrogen receptors. It’s been postulated that heighten exposure to BPA can cause endocrine problems in men and women. These problems include puberty disruption, tumor development, increased risk of breast and prostate cancer and polycystic ovary syndrome10.
Basically, your body mistakes BPA for estrogen. Estrogen is the primary female sex hormone responsible for giving women feminine body traits. The equivalent hormone in men is called testosterone.
Men and BPA
You’re probably already familiar with what happens when somebody takes testosterone. If you’ve ever seen pictures of an athlete who has benefited from the muscle-boosting effects of anabolic steroids, you know how powerful the effects of testosterone can be.
Estrogen and testosterone, for the most part, have opposite functions.
In a review published in 2016, researchers found that men exposed to higher amounts of BPA tend to have a lower sperm count and quality11 12.
However, the presence of estrogen in men isn’t entire negative. Although estrogen actually plays an important role in regulating male sexual health (in small amounts), BPA may disrupt men’s natural estrogen to testosterone balance.
There’s evidence showing that high estrogen levels in men is linked to a risk of developing prostate cancer13. However, to develop a study examining the effect a lifetime of BPA exposure has on the development of prostate cancer, researchers would need fifty or more years.
We can extrapolate from animal studies that BPA exposure may cause prostate cancer, but we can’t say how much BPA we need to come in contact with.
Women and BPA
Estrogen has been called a necessary evil for human health14. It’s a vital hormone for both genders, but levels too far above or below normal can cause chronic disease.
Elevated levels of estrogen in women can cause polycystic ovary syndrome, infertility, breast cancer and ovarian cancer.
Although the carcinogenic effects of BPA are well known, the mechanism by which it causes cancer is not well understood. It’s thought that BPA exposure may cause DNA damage and negatively influence stem cell differentiation15.
BPA and Children
Children, prenatal fetuses, and infants are at the highest risk of developing side-effects from BPA exposure.
Urinary tests show that children have higher concentrations of BPA in their bodies than adults16. Likely, this is because children have smaller body weights than adults.
The endocrine disrupting effects of BPA may be particularly detrimental to children because imbalanced hormone levels can disrupt puberty.
A study published in the Journal of Pediatric Endocrinology and Metabolism looked at the effect of BPA on young, Thai girls. They found that girls exposed to higher levels of BPA underwent puberty sooner than girls in an age-matched control group17.
Infants and unborn children may also have problems when exposed to BPA.
Research shows that children born from mothers with urinary BPA concentration greater than five micrograms per liter have lower birth weights16.
Prenatal BPA exposure is also linked to glucose intolerance and trouble metabolizing lipids in animal studies18. Although, research in humans is limited.
Infants may ingest dietary BPA through BPA bottles and breast milk.
Isn’t There an Alternative to Using BPA in Beer Cans?
The main reason why beer companies use BPA in their cans is to protect the taste of the beer. If the beer comes into direct contact with the aluminum, the acidity from the beer can cause the beer to taste metallic.
According to the president of the Can Manufacturers Institute19, at least 90% of canned goods use BPA in their linings.
Are there any alternatives?
Assuming you neither want to drink beer with a metallic taste or beer that contains BPA, the answer is not really.
What Are BPF and BPS?
The alternatives to BPA include Bisphenol S (BPS) and Bisphenol F (BPF). When they first came out, they were considered safer alternatives to BPA because they’re stable against temperature and sunlight. However, new research reveals that BPS and BPF can invoke estrogenic activity to the levels of BPA or greater15.
The chemical structure of BPF and BPS is similar to BPA, and they’re widespread in our daily lives. BPS is used to primarily in industrial products such as cleaners. BPF is used to make epoxy resins in tank and pipe linings, roads, flooring and deck toppings (among other places)20.
In a study performed in South Korea, researchers examined the effects of these two chemicals on the embryos of zebrafish21. They found that both chemicals caused an increase in thyroid hormones responsible for regulating metabolism.
Obviously, humans and zebrafish are vastly different creatures, but these results suggest that neither of these chemicals are safe alternatives to BPA.
In another study, researchers looked at the urinary concentration of BPA, BPF and BPS in 1,521 participants22. They found that participants with higher levels of BPS tended to have larger waist circumference and BMI.
Other research looking at how BPS affects gene activation found that BPS inhibits lipolysis, or the metabolism of fat23.
So, at the moment, even alternatives to BPA don’t seem to be safe for human consumption. The best way to minimize BPA consumption appears to be to avoid canned food as much as you can.
How Much BPA is Too Much?
The best way to test BPA concentrations is through a urine test. BPA has a relatively short half-life of 5-6 hours, so your body quickly excretes it.
There’s no doubt the BPA leaks into foods and beverages from cans. But how many canned food and beverages do you need to consume to change BPA concentrations in your body?
A study published in 2016 sought to answer that question by giving participants a 24-hour dietary recall survey and measuring urinary BPA concentrations24.
The study found that the consumption of one canned food that contains BPA leads to a 24% higher BPA urinary concentration than baseline.
The consumption of two canned foods leads to a 54% higher BPA concentration.
However, in this study, the consumption of canned beverages didn’t lead to significantly higher urinary BPA concentrations.
Another study comparing the amount of BPA that leaks into liquids versus solid food in the Greek market found that solid foods contained higher amounts of BPA in comparison to liquids25.
If you can’t resist the temptation to crack open a cold brewski, at least you can make up for it by cutting back on canned tuna.
Health Outlook of Regularly Drinking Canned Beer
Here’s the problem with studying BPA in food and drinks.
To understand the long-term effects of BPA, studies would have to follow people over their lifetime. Researchers can make educated guesses based on animal models and the results from short term studies. So for now, we have to be content knowing that BPA exposure is probably something we should minimize.
Drinking canned beer likely won’t have a major effect on your health unless you’re drinking a ton of it. There’s no definitive research showing that the amount of BPA leaked into beer is enough to have a significant effect on your health.
The US Environmental Protection Agency considers 0.05 milligrams per kilogram of body weight the maximum safe amount.
A study performed by the Society of the Plastics Industry26 examined how much BPA leaks into beer from the can. They estimated that a can of beer would provide 0.00011 milligrams per kilogram per pound of body weight per day. You would have to drink more than 450 beers per day to exceed the healthy limit.
So you’re probably not going to develop two heads and a tail from drinking too much beer. However, the study didn’t take into account all the other ways that humans are exposed to BPA throughout the day.
BPA pops up in many places you wouldn’t expect. In fact, cashiers tend to have higher levels of urinary BPA levels because of BPA found in receipt papers27.
Do you need to cut canned beer out from your diet completely?
Probably not. But cutting back definitely isn’t going to hurt you.
Reducing Your BPA Exposure
The vast majority of your BPA exposure comes from cans and food products. If you want to reduce the amount of BPA you consume, make small changes to your diet to eliminate packaged foods from your diet.
Hopefully, you already base your diet around natural, unprocessed foods. But if you don’t, you should make an effort to eliminate packaged foods as much as possible. Instead of buying canned tuna, try tuna steaks. Instead of canned soup, make your own from scratch.
Eliminating BPA doesn’t have to be disruptive to your lifestyle. Even if you don’t want to give up your Friday beers, consider switching to drinking beer from a bottle instead of a can.
Look for other ways that BPA sneaks into your diet. It would be a waste to take steps to eliminate canned beer from your diet if you’re going to chug a bottle of water every day.
Try to avoid commercial bottles of water, and if you’re going to carry a plastic water bottle, make sure the bottom of the bottle says BPA-free. You can also buy a water filter from a company that makes it from BPA-free plastic such as Brita.
Occasionally being exposed to BPA isn’t going to have short-term effects on your health. However, constant exposure over years can have an additive effect. If you’re pregnant, it’s particularly important that you avoid BPA products so that the development of your baby isn’t disrupted.
If you have children at home who haven’t gone through puberty yet, you may want to be extra careful with what types of containers you use for their food (hopefully you’re not giving them canned beer anyway).
By being aware of what you put into your and your family’s body, you can make more informed decisions to optimize your health.
Reboot Your Health in 30 Days With the Thermo Lifestyle
From the toxic chemicals in plastics to the endocrine disrupting additives in your meat, the Western lifestyle is slowly stealing your health. You may not immediately notice the health implications of drinking from BPA-laden containers or eating a turkey that has been injected with antibiotics, but the cumulative effects over time will leave you hormonally imbalanced and suffering from micronutrient deficiencies that can lead to disease and poor health.
Eating organic produce and grass-fed meat is a good first step to reclaim your health, but it’s just the beginning of your journey. Learning how to optimize your diet and lifestyle for hormonal and metabolic health will reinvigorate your body and help you return to a state of total wellness. The Thermo Diet will radically change how you perceive both your well-being and the world around you.
Read more about restoring your health in the toxic Western world with The Beginner’s Guide to the Thermo Diet.
Citations and Sources
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