Not all toxins are created equal. In fact, the meaning of the term “toxin” has really become watered-down due to overuse. Anything can be a toxin if you have enough of it, even water.
But what you and I care about are chemicals that can cause severe health damage in even small amounts. And that’s what we’re looking at here.
Out of the minefield of chemicals you interact with daily, these 3 are among the worst:
- Mercury and other heavy metals
BPA, short for Bisphenol A, was created in 1891. Yes, over 100 years ago.
It took about 40 years before anyone thought to study the safety of the chemical, and over the last 30 years or so, it has been a highly controversial substance.
It is used primarily to make certain plastics, which are then used in food packaging in the form of bottles and cans.
How BPA is Toxic
The endocrine system is the hormone regulating system, and any disruption to it is cause for serious worry. BPA is an endocrine disruptor, which essentially means that it interrupts the proper function of certain hormones.
What does all this mean for your health?
Well, this is where I need to let you in on an important caveat. BPA is very hard to study. It exists in small amounts, and there’s no real way to directly measure its effect on human health.
The best we can do is to look at other animal studies, where we can feed rats continuous doses of BPA, or conduct epidemiological studies, where we look for associations between BPA and health consequences.
Neither option is ideal because they rarely produce clear-cut answers. This is why there is a large amount of studies that say BPA has no or minimal health effects, while others indicate significant effects that I’m about to go over.
In one study of 1455 American adults, a higher level of urinary BPA was significantly associated with a higher risk of diabetes, heart disease, and liver damage (5).
There are also concerns over reproduction and birth defects, which is a common side effect of endocrine disruptors.
A study in pregnant rats showed that BPA is transferred from the mother to the fetuses (8). When it comes to birth weight and size, the science is murky. Some studies found a positive correlation between BPA and birth weight (higher BPA, higher weight), while others found no correlation at all, or the opposite (9)(10).
None of these studies which focused on reproduction were particularly rigorous. It’s clear that more research needs to be done before we make any conclusions either way.
Regardless of whether BPA causes birth defects, we know it’s toxic in people. The question then becomes, how much BPA will start to cause health issues? Unfortunately, we don’t have a concrete answer, and probably won’t anytime soon. Until then, it makes sense to minimize ingestion as much as possible.
What is BPA in?
In order to avoid it, you need to know where BPA is found.
The good news is that most BPA comes from what we use to eat and drink. It’s not actually in food, water, or air in serious concentrations (11). BPA moves around fairly freely, so it often transfers from containers or other products onto our food, which is when we ingest it.
Most cans are lined with resin that has BPA. This includes most types of cans, ranging from fish cans, to spaghetti sauce cans, to soft drink cans. Health Canada tested soft drink cans (I believe that’s “soda” cans to Americans) and found a significant amount of BPA in 20 out of 38 products. So while it’s not in every product, it’s quite common. They also tested soft drinks with glass bottles and found no BPA as expected (12).
In addition, BPA is also present in many water bottles. If the bottom of the bottle has a recycle code of 3 or 7, there’s a good chance it has BPA. If the plastic is heated enough, it’s possible for it to break down and allow BPA to leach out much easier (13)(14).
There are also other sources of BPA that you really have no control over, like medical devices, safety equipment (like helmets), and even some dental materials. There’s not really too much you can do about these, just make sure to wash your hands really well after going to the hospital (I hope you already do).
Other weird sources of BPA: BPA often makes its way into recycled paper products. It’s fairly common in receipt paper, and even in pizza boxes. Luckily, as someone who eats Paleo, you don’t have to worry about the pizza boxes. However, it’s still a good idea not to touch receipts and then touch food.
How can you reduce your exposure to BPA?
It’s great to be Paleo, isn’t it? You probably have very few cans in your kitchen. If you do have cans of fish, try to buy fresh whenever possible instead, even if it’s a bit more expensive.
You also probably don’t drink soda or beer, so you’re good there too. If you were to drink any of those, opt for a glass bottle instead.
The main area of concern for you and I are water bottles. If you can, get a reusable BPA-free water bottle – Nalgene is best known for these. If you reuse disposable bottles, try to replace them fairly frequently and keep them away from heat.
Overall, the Paleo-er is pretty well set up to avoid the bulk of BPA.
I’m not going to go into the science behind the toxicity of mercury too much, because we’ve known for a long time that it is definitely toxic, even in fairly small amounts. However, there is a reason I included it in this article, specifically for Paleo fanatics.
Here’s what happens:
Mercury is produced or used for a variety of industrial processes. To produce chlorine via the chloralkali process, over 90,000 kg of mercury is produced and subsequently released to the environment (15).
Mercury is also produced by burning coal or waste. The mercury then typically ends up in aquatic ecosystems. Fish ingest it either directly, or they eat other sea life that contains mercury.
Note: From here on, I’ll be referring to methylmercury as just mercury. It’s the form that it usually exists in in nature and in animals. It’s very hard to get rid of, and remains in an adult for 70 to 90 days (16).
The problem is, we eat fish and other sea life. Why wouldn’t we? They are the best source of omega-3 fats, which are crucial for good health.
But the fact of the matter is, ingesting too much mercury is a problem. In 2003, a study revealed that about 8% of people in the United States had higher mercury levels than the safe level determined by the EPA (17).
Once a sufficient level of mercury has been accumulated, effects of the toxicity will start to present as:
- adverse neurological effects (20)
- increased chance of stroke (21)
- increased risk of developing CVD (21)
- poor infant brain development and cognition (22)
Interestingly enough, mothers with high levels of omega-3 fats and low levels of mercury had children with the highest cognition scores (23).
How can you reduce your mercury intake?
I wouldn’t recommend dropping fish altogether, as we know it can be a big part of a healthy diet. What you should do, however, is limit your consumption of fish that are high in mercury.
I put together a chart of the mercury levels of common fish based on FDA data:
Don’t take these numbers as gospel, as much of that data is over 10 years old. However, the relative amounts should still be about the same.
Stick to the fish on the “good” side, avoid those on the “bad” side, and you shouldn’t have too much trouble with mercury accumulation.
The final toxin we’re looking at is actually a class of substances called phthalates.
Phthalates are typically added to plastics to increase flexibility. Like BPA, they aren’t tightly bound to anything, they can easily end up in the environment, where they eventually end up in air, food, and dust.
But unlike mercury, phthalates don’t accumulate in the body. They are excreted fairly rapidly. However, this doesn’t mean that they can’t harm us.
To start with, they exhibit anti-androgenic activity, which means they disrupt androgens. Androgens are a type of hormone, but the one you know best is testosterone.
It’s unlikely that all phthalates have the exact same effects, but they will be similar.
One study showed a significant association between phthalates in urine and preterm deliveries (24). Fertility and reproductive issues are typically the consequence of anti-androgens. They have also been linked to reduced sperm motility (25).
In addition to problems before birth, phthalates can also cause problems in infants. One study looked at levels of two common phthalates, MEP and MBP, in maternal breast milk. They found that the higher the level of MEP, the lower the free testosterone in male children. Additionally, the higher the MBP or MEP, the higher the levels of sex hormone-binding globulin, which binds to estrogen to impair its bioavailability (26).
Another study found that newborn children of mothers with high phthalate levels had more alertness problems. They were then retested 4-9 years later and the problems remained (27).
Finally, phthalates in high concentrations have also been shown to cause premature sexual development in girls (28).
In summary, phthalates are especially bad for expecting mothers and developing children.
Where are phthalates found?
The big problem is that phthalates are everywhere. Here are just some of the products in which they are commonly found:
- hair spray
- plastic bags
- garden hoses
- cleaning material
- medical vinyl gloves
This isn’t to say that every detergent or shampoo contains phthalates, because they don’t. However, they are commonly found in them.
One report in 2002 tested levels of the two most common phthalates in cosmetic products – DEP and DBP – and found:
- 71% of all cosmetics had DEP. This included deodorants, hair spray, hair mousse, and hand and body lotions.
- 100% of fragrances contained DEP
- 86% of hair gels contained DEP
The good news is that phthalate use seems to be going down. Results from a 2010 FDA survey show that only about 10% of cosmetic products overall contain any of the common phthalates. However, 11 out of 25 fragrances surveyed still contained phthalates, as did 8 out of 17 hair products. Keep in mind that this survey is far from exhaustive.
How to avoid phthalates
You’re not going to be able to avoid phthalates 100% in the modern age. However, we can try to limit our exposure to them.
Here are a few things you can do to avoid phthalates:
- don’t wear makeup, or find a phthalate-free brand if necessary
- only use phthalate-free fragrances
- don’t use hair gels or sprays
- Avoid conventional cleaners (which often contain fragrances). Try to stick to water or natural cleaning ingredients like vinegar, lemon, or baking soda for the most part.
Yes, everything might be a toxin, but that doesn’t mean that they are all equally as dangerous.
The 3 toxins we looked at in this article are fairly common, but can mostly be avoided, or at the very least reduced to an exposure level that is unlikely to cause any significant health problems.
If any of this surprised you or left you with questions, leave me a comment below and I’ll try to clear things up.
(Related: 8 Herbs That Detox Your Body Naturally)