BPA: How Your Genes Influence BPA Detoxification

Key takeaways:
~BPA and its alternative BPS are pervasive in daily life, found in plastics, food containers, receipts, and even dust, with over 90% of people exposed to detectable levels.
~ Research shows BPA disrupts hormones, increases inflammation, and impacts health conditions such as obesity, insulin resistance, and male fertility, with genetic variations influencing individual susceptibility.
~ Genetic variants influence how well you detoxify BPA, leaving some people more at risk than others.
~ Reduce BPA exposure by avoiding specific sources like plastic containers and thermal receipts, while supplements and detox methods like sweating and probiotics may help reduce its effects.

BPA and BPS: Ubiquitous Exposure to Plastics

BPA, a chemical found in some plastics, has been linked to a variety of effects on people, including obesity, insulin resistance, and epigenetic effects on babies.

BPA is everywhere in our food supply. In fact, a CDC report showed that 93% of people have BPA in their urine.[ref]

This article explains the peer-reviewed research and the links to genetic variants involved in getting rid of BPA.

Two questions that I wanted answers to about BPA:

1. 1. Is BPA really a problem?
   2. Does BPA affect everyone the same way —or do genetic variants play a role?

I’m diving into the research on the topic, looking past the hyped-up ‘sky is falling’ type of headlines to see if there really is a reason for concern.

What is BPA:

• Bisphenol-A is a component of some plastics (recycling symbols 3, 6, and 7).
• It is considered to be an endocrine disruptor because of the similarity of the molecules to estrogen.
• It is now ubiquitous in the environment, and >90% of people have detectable levels in their blood.

What is BPS:

With scary headlines about BPA, many companies have opted to make BPA-free plastics using Bisphenol S. Research now shows that BPS has hormonal and endocrine-disrupting properties similar to BPA.[ref]

How are we exposed to BPA:

While we often think of BPA as something to avoid in plastic water bottles, our routes of exposure are much greater than just in plastic containers.

For example, BPA can be found in

• teabags that contain plastic[ref]
• thermal printed receipts (some)[ref], especially when combined with hand sanitizer[ref]
• food and beverage contact paper – e.g. wrappers, paper plates, cardboard food boxes[ref]
• canned foods often have BPA in the can liner[ref]
• pantyhose[ref]
• composite dental resins and sealants[ref] as well as brackets for bonding braces[ref]
• most food – whether through plastic contamination or through the BPA in the soil[ref][ref]
• hot beverages, such as coffee from a plastic cup[ref]

A recent study examined reference levels, animal studies, and autoimmune studies. The results showed that the majority of people are exposed to BPA in food by more than two orders of magnitude over the European tolerable daily intake (TDI).[ref]

What do human studies show about BPA?

Animal studies clearly show that BPA can cause weight gain, alter hormone levels, disrupt reproduction, affect offspring, etc.[ref]

While animal studies are important and have their place, I’m going to focus here on recent human studies that take into account current human levels of exposure.

Changes to insulin:
A study published in the Journal of the Endocrine Society looked at the effect of BPA on insulin secretion and glucose levels. The researchers gave an oral dose of BPA at 50 ug/kg body weight, which is the daily limit set by the EPA as being safe daily exposure over a lifetime. They found that this BPA dose increased initial insulin release (oral glucose tolerance) but then showed no statistical difference with the later phase blood glucose response. This is an important study because they used the EPA guidelines for an amount of BPA that was not supposed to elicit a response.[ref] I found it interesting that there was a large variation between individuals in their BPA levels over time after ingestion — individual rates of BPA metabolism varied a lot!

Exposure starts before birth:
Another recent study looked at BPA and PFOAs in over 6,000 newborns to determine if there was an effect on birth size. Researchers found that over 90% of the infants had detectable levels of BPA in their blood, and over 99% had detectable PFOA and PFOS. The study did find that average BPA levels were higher in twins born with lower birth weight, possibly because higher BPA levels also correlated with a greater number being born before 37 weeks of age.[ref] Most remarkable to me is that 90% of babies were born with BPA in their blood. The infants in the study were born between 2008-2010 in NY.

Male fertility and testosterone reduction:
BPA was shown in a recent study (and several previous studies) to reduce sperm motility in men.[ref] Previous studies also showed decreased testosterone levels in male teenagers with higher levels of BPA.[ref] Other research shows that BPA disrupts the activation of androgens, leading to reduced testosterone and increased belly fat.[ref]

Linked to obesity:
A small study published in 2018 found that children and teens with higher BPA exposure (the top third of the group) had a 12-fold increased risk of obesity.[ref] This was just one study in a long line of human studies that showed that higher BPA exposure increases weight.[ref][ref][ref][ref][ref][ref] In addition to the effect on testosterone and abdominal weight gain, BPA stimulates the overexpression of GPR30 in fat cells, which prevents the burning of the fat for energy.[ref]

Inflammation:
A study from August 2018 found that BPA at normal exposure levels alters insulin response in a way that is independent of adipogenesis (fat creation).  The study found that BPA causes a low-level inflammatory response.[ref] This is in line with previous epidemiological studies that tie higher BPA levels to insulin resistance in men, women, and children.[ref][ref][ref]

Myocarditis and cardiovascular disease:
Estrogen receptors are located in mast cells and cardiac muscle cells in the heart. A 2019 study in mice found that exposure to BPA in their drinking water increased their susceptibility to viral myocarditis and pericarditis. The higher BPA levels also activate mast cells in the heart.[ref] Additionally, activation of neuropeptide Y (NPY) by BPA not only increases obesity but also contributes to the pathogenesis of heart disease.[ref]

Altered lipid profile in babies:
A study of maternal BPA, BPS, and BPF levels showed that babies born to mothers with higher bisphenol levels had altered fatty acid profiles.[ref]

Lifehacks for getting rid of BPA:

Stopping exposure to BPA:
This seems like a logical first step, but it can be more difficult than you may first think. Take a look at this list of common exposure routes to BPA and figure out where it makes sense to focus your attention.

Realistically, it isn’t possible to cut out all exposure. Instead, choose the areas where you will get the most impact.

Common sources of BPA, and BPS exposure, include:

• plastic water bottles
• teabags that contain plastic[ref]
• plastic food containers
• thermal printed receipts (some, not all)[ref], especially when combined with hand sanitizer[ref]
• pantyhose[ref] and polyester
• composite dental resins and sealants[ref]
• brackets for bonding braces[ref]
• most food – whether through plastic containers or through the soil[ref][ref]
• drinking hot beverages, such as coffee, from plastic or disposable cups[ref]
• clothing (82% of infant clothing tested had BPA)[ref] athletic clothing and socks are big sources of transdermal BPA

Dust your house:
One route of exposure that is especially important in children is through contact with dust. One estimate showed that dust contributed to about 10% of BPA exposure.[ref] A good reason to get out a dust rag and take care of all those dust bunnies.

6 Natural Supplements and the Detoxification of BPA:

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