Are Preservatives Bad for You?

Growing up, I never wondered how food lasted on grocery store shelves or in the pantry. That box of mac n cheese or jar of alfredo sauce was just made to sit in the pantry so it did. Now, as an adult, it seems so obvious. How do they get that stuff to last? 

Preservatives. 99% of the time, artificial preservatives. 

It’s not just pantry food either, it’s some cold things. In one sense, cold items are less likely to have preservatives because more of them are designed to be eaten fresh. But at the same time, many still have preservatives to extend that time. Think meats and cheeses, which typically have nitrites to help them last and reduce the risk of foodborne illness

I know in the natural living world, preservatives can get a bad rap. They’re sometimes talked about this evil addition to our food that should absolutely be avoided. But what’s the truth? Are preservatives bad for you? Should we avoid eating foods with added preservatives? 

Let’s explore that.

It depends on how they’re used

Why preservatives are important

So are preservatives bad for you?

Which preservatives should you avoid?

A note about “safe” limits

General advice on dealing with preservatives

Summary / TLDR

It depends on how they’re used

Something you’ll run into a lot when considering what is “safe” or not to use is the necessity of considering how it’s being used and consumed. 

One thing may be perfectly safe on the skin but questionable in food. Titanium dioxide is a great example of this. Though some think it’s safe for use in food, others find it questionable and potentially toxic. However, for use on the skin, it’s been shown to be perfectly safe. So, potentially, to be safe you would avoid consuming titanium dioxide but be fine with a sunscreen that has it. 

A lot of this has to do with the fact that our skin and digestive systems absorb particles differently. First of all, the stomach breaks down particles more, so the breakdown of certain particles can cause problems if they’re made too small to be properly excreted. But also, the stomach is just going to absorb more things than the skin, because that’s what it’s designed to do, and distribute it throughout the body. That means it’s more likely that something that really shouldn’t be floating around our body will negatively impact us. If it’s just on our skin, it more than likely won’t break down or absorb enough to really hit our system. But obviously that can only be taken so far.

Bottom line: We should generally be more careful and strict with what we’re willing to consume than with what we put on our body, because it will impact us more and is more likely to have an impact in the first place.

Because of this, we’re going to focus on preservatives in food for the rest of the post. I may do something on preservatives in topical products some day. We’ll see.

Why preservatives are important

First off, it’s important to clarify whether we are talking about natural or artificial preservatives. There are several natural preservatives and a couple of them have been used for probably all of time. The most commonly and easily used throughout time would probably be salt. Salted meat, salted butter, and so on last longer than unsalted versions. 

This practice is still used today. If you take a look at a box of salted butter at the grocery store, you’ll see two ingredients: cream and salt. Contrary to what people may think, that salted butter is supposed to add salt to your recipe, the salt is there previously as a preservative. It may offer some flavor enhancement, but that’s not the purpose of it’s use. 

Unsalted butter simply uses a different preservative, typically a product of fermented milk, that helps it last twice as long. Some countries don’t allow this, but it’s probably more commonly purchased in the US than unsalted butter.

Other natural preservatives are ascorbic acid (vitamin C), citric acid, tocopherols (vitamin E), and betanin.

Thinking historically, adding preservatives like salt to your food is very important. First, people didn’t have year round access to everything and they couldn’t just go to the store to pick up an extra pork roast. They had to farm and hunt their food or at least rely on local farmers and hunters at the market. So then you have to try to stretch out the amount of time you can make these limited resources last (kind of like using a greenhouse to extend your growing season) by preserving some of them. 

Additionally, the reason food goes bad is because there are tiny microbes and bacteria that, as food ages, start to interact with the food and turn it “bad.” This natural decomposition process has negative byproducts that make humans (most animals really) sick. Some are more dangerous than others. Some foods rot more quickly than others and have more dangerous decomposition products than others. The idea of adding preservatives to tackle this problem is that, by reducing the rate at which these microbes are causing the decomposition, you reduce the risk of humans consuming microbes and byproducts that will make them sick. 

That pretty much sums up the main reason we use preservatives the way we do now. Preservatives are helpful for keeping things on the shelves longer for the way we gather our food today (from the grocery store) and there’s been a big public health focus on reducing foodborne illness over the last 100 years. 

We’ve found ways to do this much more effectively through artificial preservatives. Some artificial preservatives simply stave off the microbes that cause food to go bad for longer and others kill them. This is a great thing when just considering shelf life and reducing food borne illness. In this sense, preservatives of any kind are very GOOD for you.

But are artificial preservatives bad for you in other ways?

So are preservatives bad for you?

Well, maybe. Overall, I would say preservatives are a great thing. Getting food poisoning or a dangerous disease from eating bad food is a very real danger made much smaller by the use of preservatives today. However, there are some groups calling attention to the fact that some preservatives may not be that good for you. 

To that I say, it depends on the preservative. Some will say it’s any artificial preservative, but I don’t think there’s enough evidence for that. 

Natural preservatives obviously seem fine, but some people will even have qualms with that, like that we should be careful how much salt we are adding to our diet through use of salt as a preservative. Which… yes. But if you’re eating a decent diet and not just loading up on processed foods, that shouldn’t be a problem. 

Some people say any artificial preservative is a no go. I think it’s fine to want to avoid artificial preservatives for the most part, but it’s a little bit of a red flag when someone says you should boycott an entire group of something without any context or actual evidence for why. All the artificial preservatives we use are deemed “generally recognized as safe” in the amounts we use them at, but I’d argue there are certainly a few to avoid that do seem to have some evidence behind them to the tune of possible cancer development and other issues. 

Which preservatives should you avoid?

There are a few preservatives that many are choosing to avoid now because evidence is emerging that they’re likely having adverse effects on humans. Let’s look at those.

BHA/BHT

Butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) are considered by some as toxic and others say it’s totally safe. It’s surprisingly controversial. Though not really that surprising. I feel like everything I cover on this blog is like this.

So what does science say? Well, regardless of toxicity, BHA and BHT are actually anticarcinogens. That’s because BHA and BHT are basically fake vitamin E, which is an antioxidant. However, this doesn’t necessarily mean that BHA and BHT aren’t also carcinogenic. Oddly enough, compounds can perform in multiple contradictory ways sometimes. 

In this case, some evidence shows that BHA is likely safe while BHT may be somewhat carcinogenic and particularly affects the liver.

However, when all the data is taken together, it looks like any effects of BHA and BHT are controlled for by usage limits. This report by the European Commission Scientific Committee on Consumer Safety is a really interesting read if you feel like nerding out on the details of BHA and BHT research. It does not include all research and is slightly dated, but it is thorough and still representative of findings. 

To boil it down at the risk of losing some of the depth of the issue, BHA, again, appears largely safe and BHT appears to be safe with some concerns that are controlled for by usage limits. 

There is decent evidence that BHT causes liver changes that negatively impact health in animal studies and this is likely the cause for other issues such as hormone-related issues. BHT has been basically ruled out as an endocrine disruptor and levels have been set for BHT use that should far side step any development of liver issues like seen in the animal studies. 

So could BHT cause health issues? It’s mildly possible. As usual, if you prefer to avoid it because of that small possibility, do your thing. I tend to worry more about endocrine disrupting compounds because the dose is difficult to control due to the hypersensitivity of the endocrine system. But the evidence seems to show that the primary actor of BHT is not on the endocrine system and that any impacts to this are secondary. So I wouldn’t worry about this one too much personally. 

But overall, BHA and BHT, especially at the levels we consume, are unlikely to cause any kind of harm. The allowed levels are way lower than what we see to cause any change in animal studies. Obviously if you just eat excessively, you’re always at a higher risk of excessive consumption of a variety of compounds. And to be clear, consuming BHA/BHT at high levels would be dangerous. But that is highly unlikely to happen thanks to use limits currently in place. But generally speaking, you should be fine.

Nitrites

Nitrates and nitrates are used pretty commonly, especially in meats, to prevent spoilage and add color and enhance flavor. And as with so many of the things I share on here, whether they’re bad for you or not is a little more complicated than a lot of people make it out to be.

First, though nitrates and nitrites are considered artificial preservatives because of the way they are added and because they are made rather than occurring naturally, nitrates and nitrites themselves are naturally existing compounds. 

(I feel like so many of the issues I talk about come down to chemistry, I’m sorry! But that’s the stuff of life!) 

And though you will hear all about how you should avoid nitrates and nitrites added to foods, that may lead you to believe that’s because nitrates and nitrates are just bad. That’s not the full story though. Did you know that vegetables actually have higher levels of nitrates than processed meats? They’re not inherently bad.

Nitrates and nitrites are related, nitrates being a compound that can turn into nitrites through normal body processes, so I’ll talk about them the same way here. The problem with nitrates and nitrites is this: Nitrates can either break down into something good for you (nitric oxide) or something bad for you (nitrosamines). (Healthline actually has a very easy to follow rundown on all of this if you want to go a little deeper on this.)

Nitric oxide is actually helpful for issues like high blood pressure and thus nitrites are used as medicine for this purpose. Nitrosamines, on the other hand, have been considered a carcinogen with decent evidence that they can increase risk of developing cancer in a variety of organs and may be genotoxic.

So what determines whether nitrates and nitrites will become nitric oxide or nitrosamines. Mostly, the right circumstances/environment. Chemistry typically seeks balance in the easiest way it can find it. The reason nitrites are problematic is that they are “unbalanced” and less stable, so they want to regroup with other elements. A lot of the time they do this with oxygen, which is when they become nitric oxide.

However, if there are plenty of amines available (amines are protein, so this ties in why meat can be an issue), they may form nitrosamines instead. This is especially true when meat is cooked at high temperatures (which it often is) because heat helps break the amines apart so they are free to bond with the nitrites in the first place. 

Though vegetables technically have higher rates of nitrates than processed meats, they don’t have much protein and are not typically cooked at temperatures as high as those used for meats. This is why it’s important to distinguish that it’s not just nitrates/nitrites or even whether they are naturally occurring or added. It has a lot more to do with the total combination of processes coming together to create the perfect storm.

To boil all this down to simple language: Nitrates and nitrites can be problematic because they can break down into nitrosamines, which are harmful to humans. However, they are the most concerning in processed meats because of the combination of other elements as well as the methods used to cook them that lead to the perfect situation for nitrosamines to form. This is why it is considered wise to avoid added nitrates and nitrites as much as you can. 

However, do not be fooled by products that state they contain “natural nitrates” or “nitrates only naturally from celery powder.” Nitrates are nitrates, the body doesn’t know the difference between artificial and natural. They will be processed the same way. Natural nitrates from celery will have the same effect. 

If you are going to avoid added nitrates and nitrites, you want to completely avoid them, not just artificial ones. 

And as with all things, nitrates and nitrites are mostly okay when we limit our consumption of them. With this one I would say it is probably wise to be even more mindful to limit your consumption. A balanced diet can also help reduce the production of nitrosamines even when we consume nitrates and nitrites. If you want to completely avoid them, that’s great. It’s also not going to kill you to have a little here and there.

Propyl gallate

Propyl gallate is another preservative that essentially could be toxic if consumed at high doses but practically isn’t toxic because we don’t consume it in high enough doses.

Propyl gallate may have some toxicological effects in general as ecotoxicity tests show that it may cause cell death in certain species. I’ll admit that’s not something I completely understand nor can extrapolate. Some animal studies find that propyl gallate probably is a force behind negative impacts on fertility and gestation as well as potential DNA damage.

Other evidence shows that, specifically for use in animal feed, propyl gallate is safe and even potentially beneficial for animals when capped at various levels considered safe for each animal. This indicates that there are unsafe levels but we’ve established them and can safely utilize the substance under those levels. 

This may seem kind of confusing. Some say it’s bad, others say it’s safe. If you’ve been around here for a while you’ll know that’s kind of the case with most things. Sometimes it’s a matter of interpretation, sometimes it’s bias, sometimes it’s just looking at one side of the picture. 

One thing I can say for sure is that the issue with propyl gallate (and really most of these additives) is that the issue occurs when intake is excessive. The same can be said of any naturally occurring vitamin or mineral. If taken in excess, it negatively impacts the body. 

So will propyl gallate harm you? Probably not in the quantities we consume it in. But there could be minor effects we aren’t accounting for or general overconsumption could lead to issues. 

Sodium benzoate

Sodium benzoate may be much more straightforward. Obviously, there’s still nuance and complexity, but the evidence more clearly paints the picture that sodium benzoate is likely harmful. Probably not necessarily at the concentrations we consume it in, but that threshold is much lower than for other substances.

Because of this, there is a big push that “safe levels” should be closely followed and possibly even reevaluated as more evidence comes out.

One thing that’s helpful is that a lot of the evidence says the same or at least similar things. It appears that sodium benzoate negatively impacts kidney and liver function, as well as hormone function, embryonic development, and oxidation.

Granted, most of these effects are found in animal studies, so it’s not completely generalizable to humans. I haven’t been able to find a lot of quality evidence related to humans. However, the consistency of these findings in animal studies leads to probable impacts for humans. 

The other thing about these findings is that, while there is definitely dose dependence, the threshold appears much lower. 

All in all, I’d be more wary of sodium benzoate than some of the other preservatives on this list, though I still wouldn’t freak out about it. The levels we consume are unlikely to have major effects. But because sodium benzoate does appear to have endocrine impacts, which are more sensitive to small changes, it’s something to be more mindful of.

A note about “safe limits”

Theoretically, the outlined “safe” limits for concentrations of anything within a product are so far below what any research has shown to have any kind of effect that you can rest assured you’re unlikely to experience harm from consumption of that compound.

It’s my philosophy to generally trust the science and the recommendations but to also take my brain to it to say what seems reasonable and what I’m willing to risk messing with or not. If you want to learn more about how “safe” limits are set as well as problems and non-problems with that, I have a post coming out about this soon.

And as always, if you want to try to totally avoid something because of any remote possibility a negative effect could occur, do your thing! 

General advice on dealing with preservatives

Preservatives are probably fine. They’ve been tested and the allowable concentrations have been set far below what may cause harm. At the same time, there is a level that could be harmful, so that can feel sketchy. But really, eating too many carrots or too much of a vitamin or mineral can be harmful so the fact that something could cause harm at some level isn’t the best measure for what we do or don’t consume.

At the same time, you don’t necessarily have to consume preservatives. There are options available that contain less or even no preservatives now, though they can be difficult to find and you should be mindful of deceptive marketing (like when they say nitrites only naturally from celery salt,” same end result). For meat, try to source locally and buy products with no added nitrates and nitrites.

For other preservatives, you can mostly avoid them by limiting the amount of processed food you consume. I know that seems like the answer to everything here. It’s not the only way to live your life, but it is certainly an “easy” way to avoid so many things that are or are potentially bad for your health. Fact of the matter is we add stuff to food to make it last on the shelves or taste better or look better so it will sell better and we probably pay for that in some ways. 

It’s not plausible for everyone to make their own this or that or to avoid processed food. The easiest way to do it is probably just to omit foods from your diet you don’t have time to make and don’t want to eat processed. A diet of veggies, fruit, meat, and some grains, seeds, and so on, can fill your dietary needs, probably save you money, and help you avoid a lot of the junk added to our food. 

So will preservatives kill you? Probably not. But you can also relatively easily avoid them and reap probably several health benefits. 

Summary / TLDR

Artificial preservatives in food can be a controversial topic. I didn’t cover every single one of them here but most of the major ones. What I found in the research is that the limits for concentrations of these preservatives seem reasonable. 

This is one of those topics I expected to be like yes! Preservatives are bad for you! But honestly I just couldn’t find evidence to support that. As I’ve said a couple times, yes, too much of them can be, but too much of very good things can be as well. And also, the use of preservatives has probably saved more lives by preventing foodborne illness than it has negatively impacted anyone. Generally speaking, preservatives are a very good and necessary thing!

There are possibly unintended and unseen consequences of artificial preservatives that are difficult to research and quantify and that may be missed here. However, overall, it seems that likely artificial preservatives are not something you should be very concerned about.  

Now, the exception to this would be some details around nitrites and sodium benzoate. 

First, sodium benzoate may have endocrine disrupting effects, so I’d be more wary of it. Of all the preservatives we looked at here, this one appeared the most problematic. It’s likely fine to consume because the concentrations are very limited, but it is questionable. If I were to pick one for you to choose to avoid, it would probably be sodium benzoate. 

Second, nitrites are problematic in meat because of this “perfect storm” idea. Nitrites themselves can be harmless and potentially even beneficial. But nitrites combined with protein and heat can create a compound that is arguably harmful to multiple organ systems as well as carcinogenic. For this reason, I would say it’s likely wise to limit your consumption of nitrates/nitrites in meat. Don’t freak out about it, but be mindful of it. 

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