There are many reasons why I avoid eating canned soup. For one, the sodium content tends to be astronomical. There’s also the cost and lack of flavor, compared to fresh, homemade soup. A big factor in my avoidance, though, is the potential toxins in soup, including BPA.
It seems everything is toxic these days, geez.
BPA stands for bisphenol-A. This chemical is often found in the linings of food packaging, where it protects food from spoiling. The irony is that BPA is hazardous to health in a variety of ways, including being a known endocrine disruptor.
This is why BPA is banned for use in food packaging in the European Union. In the U.S., though, the Food and Drug Administration (FDA) still considers it ‘safe’. That means many food manufacturers still use it in their cans and plastic food packaging.
We know that BPA is bad for health. But how much of a problem is it really?
Do we absorb BPA from food?
The rule of thumb in toxicology is that the dose makes the poison. So, how much BPA do we need to be exposed to before it starts showing up in the body and causing damage?
One small study with robust methodology found that:
healthy adults who ate canned soup for five days had levels of BPA in their urine 1221% higher than after they consumed fresh soup made without canned ingredients.
In real terms, the participants’ urine contained 1.1 micrograms per liter of BPA after eating fresh soup, versus 20.8 mcg/L after canned soup. On average, participants had BPA levels 22.5 mcg/L higher after eating canned soup compared to a week of fresh soup.
This study and several other studies demonstrate that we do absorb BPA from food. This wouldn’t necessarily be a problem if BPA didn’t have harmful effects on our health.
The harmful effects
Researchers have known about the harmful effects of BPA on human health for decades. Most of the negative impact of this chemical comes from its role as an endocrine disruptor. That means BPA upsets hormone balance in the body.
Specifically, BPA mimics estrogen, meaning it can either block or activate estrogen receptors and throw the body’s natural estrogen levels and activity off kilter.
BPA is also bad news for neurons, with harmful effects on cognitive, behavioral, and emotional health.
Some research even suggests that maternal BPA exposure can compromise gut microbiota in infants.
Finally, scientists looking into BPA’s effects on the liver recently stated in a 2024 paper that:
“Notably, BPA is implicated in every stage of non-alcoholic fatty liver disease (NAFLD) onset and progression, surpassing hepatitis B virus as a primary cause of chronic liver disease worldwide.”
The authors took care to note that BPA is just one of the problems though, with BPA alternatives also posing a hazard, in addition to microplastics, nanoplastics, and additional plastic derivatives.
The size of the problem
Many food manufacturers have begun replacing BPA in packaging over concerns about health (and their bottom line). Unfortunately, the chemicals used to replace BPA are often very similar but have been subject to far less scrutiny.
In fact, many of the chemicals replacing BPA are simply other bisphenols that seem to behave in the same way as BPA.
The upshot is that BPA-free cans may still pose a health hazard, just not one we can spot from looking at the label.
The most common BPA replacement seems to be bisphenol-S (BPS). Others include bisphenol-F and bisphenol-A diglycidyl ether (known as BPF and BADGE).
These chemicals are not inert and may be just as troublesome as BPA itself. They also accumulate in human tissues and upset hormone balance just like BPA.
BPF in particular seems to negatively affect male fertility and female fertility, reducing:
- Testosterone
- Luteinizing hormone
- Follicle stimulating hormone
- Sperm production.
If you’re trying to conceive, it’s especially important to avoid BPA and its alternatives as much as possible.
Despite knowing about these harmful effects of BPF and other BPA replacements since at least 2015, federal regulators in the U.S. continue to allow their use.
Is it still in cans?
Consumers have long pushed for can manufacturers to eliminate BPA, and that campaign has been quite successful. Does this mean that most canned soup is safe these days?
Almost, but not quite.
According to the Can Manufacturers Institute, a 2019 report found that:
Nearly 100% of cans are made with new linings instead of BPA.
These new linings tend to be made from:
- Acrylic
- Polyester
- Non-BPA epoxies
- Olefin polymers
- Legacy vinyl linings.
The CMI claims that new linings are deliberately designed to avoid endocrine disruption. It also states that “The industry does not intentionally add BPF, BPB and BPS substitute in can linings.”
Per the report, of the 234 samples collected in Washington State, only two had a BPA-based liner. Both cans were imported products (coconut milk from Thailand and peaches from Australia).
What’s in cans these days?
Most canned foods in the CMI report used polyester linings and coatings for the base and top. However, several soup cans had acrylic or vinyl linings alongside polyester.
Here’s a quick breakdown of these lining types:
| Vinyl | Polyester | Acrylic resins | Oleoresins |
|---|---|---|---|
| Typically polyvinylchloride (PVC) | Persistent in the environment | Don’t biodegrade well | Often made using plant-derived materials (such as tree resin) |
| Often made with phthalates | Toxic to aquatic life | Toxic in the wider environment | Tend to be more biodegradable |
| Potential endocrine disruption | Tend to contain polystyrene | Very little known about their composition | |
| Vinyl is a known carcinogen | Polystyrene contains styrene, a known carcinogen and endocrine disruptor | Very little research into health effects | |
| Can affect normal child growth and development |
The worst canned products for BPA
If it’s not possible to avoid BPA lined cans entirely, I recommend prioritizing avoiding acidic canned food. That means:
- Tomatoes and tomato-based products, including soups, salsa, and sauces
- Fruits, including peaches, apples, strawberries, etc.
- Pickles
- Jams and jellies
- Sauerkraut.
Glass is the better packaging option for all of these as it is inert and can be recycled.
Check the lids of glass jars and bottles. Many lids also contain BPA or some other undesirable lining material. Invest in BPA-free reusable lids if you are canning fresh foods at home.
Some of these foods are also available in TetraPaks, although you’ll also want to check which chemicals are used to line those.
Finally, whether you’re stocking up on canned goods or buying fresh food at the store, beware of the receipt. These are another major source of BPA or BPS exposure!