Episode 202: BPA Overview

Episode 202: BPA Overview

Written by Cameron Carlisle, MSIV, Ross University School of Medicine. Comments by Hector Arreaza, MD.

You are listening to Rio Bravo qWeek Podcast, your weekly dose of knowledge brought to you by the Rio Bravo Family Medicine Residency Program from Bakersfield, California, a UCLA-affiliated program sponsored by Clinica Sierra Vista, Let Us Be Your Healthcare Home. This podcast was created for educational purposes only. Visit your primary care provider for additional medical advice.

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Arr: Welcome to another episode of Rio Bravo qWeek. My name is Hector Arreaza, I’m an associate program director and faculty in the Rio Bravo Family Medicine Residency Program. Today my co-host is Cameron Carlisle, who is a 4th-year medical student finishing his last rotation of med school. Welcome, Cameron, please introduce yourself.

Arreaza: What are we talking about today, Cameron?

Cam: Dr. Arreaza, did you know you’re probably carrying around a chemical in your body that mimics estrogen? In fact, a 2004 CDC study found over 92% of Americans had detectable levels of Bisphenol A (BPA) in their urine. 

Today’s topic is BPA.

BPA is everywhere: receipts, water bottles, canned foods, baby bottles, and even our dental fillings. It’s one of the most ubiquitous endocrine-disrupting chemicals (EDCs), which interferes with the body’s hormone systems. That’s why today’s episode is about making the invisible visible. 

Our goals for today’s podcast:

• Break down what BPA is
• Show how it affects the human body
• Explain how you and your patients can limit exposure
• Empower both clinicians and the public with real, practical information

Arreaza: Thanks for clarifying BPA today. It seems like we always have to learn about a new carcinogen or toxic substance that we are exposed to. I remember when I was a child, Yellow #5 became very concerning for the general public but it is still being used in our foods. So, it’s good you are talking about this. 

What Is BPA?

Cam: Bisphenol A (BPA) is an industrial chemical used since the 1950s, primarily in polycarbonate plastics and epoxy resins. It makes plastic clear, and is often found in:

• Water bottles
• Canned food linings
• Baby bottles (pre-2012)
• Takeout containers
• Cash register receipts
• Dental sealants

Arreaza: So, I’ve seen the “BPA-free” labels many times, and today I’m glad you are going to shed some light about it.

Cam: What’s alarming is that BPA leaches out of these products, especially when exposed to heat, acidity, or repeated use. A Harvard study found that people who drank from plastic bottles for just one week had a 69% increase in urinary BPA levels (Carwile & Michels, 2009).

Arreaza: That’s a lot of people 69%. Section 3: What happens when BPA gets into our body? How BPA Works in the Body

Cam: BPA is classified as an endocrine disruptor, meaning it can bind to estrogen receptors and mimic or block natural hormone functions.

It affects:

• Reproductive systems (both male and female)
• Neurodevelopment
• Thyroid signaling
• Pancreatic β-cell function
• Metabolism and fat storage

Even low-dose exposure can disrupt cellular function. BPA acts as a xenoestrogen (foreign estrogen) and has been shown to alter DNA methylation, leading to epigenetic changes that persist across generations (Manikkam et al., 2013).

Arreaza: So, BPA can cause epigenetic changes that can be inherited. BPA can persist for generations in your offspring.

BPA’s Health Impacts – What the Research Says

Here’s where it gets serious. Let’s go system-by-system:

1. Reproductive Health

• Females: Linked to PCOS, infertility, and early puberty (Peretz et al., 2014).
• Males: Reduced sperm count and motility; altered testosterone levels.

2. Pregnancy and Birth Outcomes

• Increased risk of preterm birth, gestational diabetes, and low birth weight (Snijder et al., 2013).
• Studies show BPA crosses the placenta, directly affecting the fetus.

3. Neurological Development

• Associated with ADHD, anxiety, and impaired executive function in children exposed in utero (Mustieles et al., 2015).

4. Metabolism and Diabetes

• BPA exposure is linked to insulin resistance, obesity, and type 2 diabetes, even at low doses (Lang et al., 2008).

5. Cancer

• Animal and human data link BPA to increased risk of breast and prostate cancer via estrogenic mechanisms.

6. Mortality

• A 2020 JAMA study found individuals with higher BPA levels had a 49% increased risk of all-cause mortality compared to those with lower levels (Gao et al., 2020).

Arreaza: You are scaring me. I wonder what my BPA level is in my blood. Actually, BPA can be detected in urine. This is the most common approach for population-level biomonitoring, because BPA and its metabolites are mostly excreted in urine. Studies have found that BPA is present in most people, even up to 85–99% in large cohorts. 

Cam: That’s literally everyone. 

Sources of BPA Exposure

Let’s talk about things we use every day:

• Thermal receipts (like from Target or Starbucks): BPA can transfer onto your skin and be absorbed, especially if your hands are wet or lotioned.
• Canned soups: One study showed that eating canned soup daily for five days led to a 1000% increased urinary BPA levels (Carwile et al., 2011).
• Plastic water bottles left in the car on hot days or plastic food trays for microwaving = chemical leaching.
• Baby bottles and pacifiers (pre-2012): primary concern for newborns.

Arreaza: So, Cameron, you were exposed to BPA as a baby.

Cam: Here’s the jaw-dropper: We ingest up to 5 grams of plastic per week, roughly the weight of a credit card (WWF, 2019; University of Newcastle). This includes microplastics like BPA, which enter through food, water, and air.

Arreaza: So, it translates into 40 lbs of plastic in a lifetime, by age 70. What can we do as family physicians?

Family Medicine and Preventive Care

As family physicians, we are at the frontlines of prevention. Our role includes:

• Anticipatory guidance: during prenatal visits, well-child visits, and chronic disease management
• Screening opportunities: ask about storage habits, microwave use, and receipt handling
• Environmental health counseling: AAFP recommends addressing endocrine disrupting chemicals (EDCs) when relevant to a patient’s concerns.

It’s not just about treating diabetes or obesity. It’s about recognizing that environmental exposure may be a root cause.

Arreaza: Prevention is my favorite topic!

Cam: One helpful clinical practice:

Arreaza: What else can we do to reduce BPA exposure?

Practical Steps to Reduce BPA

Here’s what patients and doctors alike can do today:

• Switch to BPA-free products, but be careful, as replacements like BPS or BPF may also be harmful (Rochester & Bolden, 2015).
• Avoid microwaving or dishwashing plastic containers.
• Use digital receipts.
• Filter tap water using carbon filters, which can reduce microparticle ingestion.
• Choose fresh produce over canned goods when possible.

Also, wash your hands after handling receipts, especially before eating or touching your face.

Arreaza: What is our government doing to protect us?

Public Health and Policy Updates

Regulations are slowly catching up:

• The FDA banned BPA in baby bottles and sippy cups in 2012.
• The European Union has stricter limits, and France banned BPA in all food packaging in 2015.
• California’s Proposition 65 requires BPA warning labels.

Arreaza: Proposition 65, passed by direct voter initiative in 1986, “WARNING: This product contains chemicals known to the State of California to cause cancer and birth defects or other reproductive harm.”

Arreaza: The FDA is planning to phase out petroleum-based food dyes (certified color additives) from the American food supply – marking a significant milestone in the efforts to protect the public. 

Cam: Many products still contain BPA analogs (BPS, BPF), which are not yet well-regulated.

This is where clinician advocacy matters, where we can guide public opinion and support legislative change.

Arreaza: So, millions of pounds of toxic substances are produced by many industries in the US. As physicians, we have to stay informed and update our patients.

Cameron: How can we wrap up this episode?

Conclusion and Takeaways

• BPA is a hormone disruptor hiding in plain sight.
• People are exposed to BPA every day, but small lifestyle changes can dramatically reduce it.
• Family medicine has a role in education, prevention, and advocacy.

Let’s all be part of the solution for our health and future generations. Stanley (tumblers) are not sponsoring this episode, and we did not receive any money from them. 

Arreaza: That’s it for today’s episode of Rio Bravo qWeek. If you enjoyed this episode, share it with a colleague or medical student who may need to know about BPA. I’m Dr. Arreaza, signing off.

Cameron: Hopefully, in the future I will talk to you about more endocrine disrupting chemicals. Thanks for listening.

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Even without trying, every night you go to bed a little wiser. Thanks for listening to Rio Bravo qWeek Podcast. We want to hear from you, send us an email at [email protected], or visit our website riobravofmrp.org/qweek. See you next week! 

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References:

1. Carwile, J. L., & Michels, K. B. (2009). Urinary bisphenol A and obesity: NHANES 2003–2006. Environmental Research, 111(6), 825–830.
2. Carwile, J. L., et al. (2011). Canned soup consumption and urinary bisphenol A: A randomized crossover trial. JAMA, 306(20), 2218–2220.
3. Centers for Disease Control and Prevention (CDC). (2004). Fourth National Report on Human Exposure to Environmental Chemicals.
4. Gao, X., et al. (2020). Urinary bisphenol A and mortality risk. JAMA Network Open, 3(8), e2011620.
5. Lang, I. A., et al. (2008). Association of urinary bisphenol A with medical disorders and laboratory abnormalities in adults. JAMA, 300(11), 1303–1310.
6. Manikkam, M., et al. (2013). Epigenetic transgenerational inheritance of disease. PLOS ONE, 8(1), e55387.
7. Mustieles, V., et al. (2015). Bisphenol A and neurodevelopmental outcomes in children. Environmental Health Perspectives, 123(7), 689–695.
8. Peretz, J., et al. (2014). Bisphenol A and reproductive health. Environmental Health Perspectives, 122(8), 775–786.
9. Rochester, J. R., & Bolden, A. L. (2015). Bisphenol S and F: A systematic review. Environmental Health Perspectives, 123(7), 643–650.
10. Snijder, C. A., et al. (2013). Fetal growth and prenatal exposure to bisphenol A. Environmental Health Perspectives, 121(3), 393–398.
11. World Wildlife Fund (WWF). (2019). No Plastic in Nature: Assessing Plastic Ingestion from Nature to People.
12. University of Newcastle (Australia). (2019). Human Consumption of Microplastics.
13. Theme song, Works All The Time by Dominik Schwarzer, YouTube ID: CUBDNERZU8HXUHBS, purchased from https://www.premiumbeat.com/.