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Many Omega-3 Fish Oil Supplements Are Rancid – Here’s Why

Rows of fish oil tablets.
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No one likes the smell of rancid fish. The sour, fishy aroma is a potent signal to our bodies: danger – do not eat. And yet, a significant proportion of the fish oil supplements millions of us glug down every day may be rancid, too.


According to one recent analysis of 72 omega-3 supplements sold in the US, 68% of flavored supplements and 13% of unflavored supplements exceeded acceptable oxidation levels. The first figure is particularly alarming; it raises the concern that a majority of flavored omega-3 supplements sold in the US are actually rancid, their acrid taste masked by artificial flavorings.


But why is this mass oxidation occurring? And does it pose a health risk to consumers? Technology Networks asked one of the researchers behind the pivotal study, Leigh Frame, an associate professor of clinical research and leadership at George Washington’s School of Medicine and Health Sciences.

Leo Bear-McGuinness (LBM):

How did you carry out your research?


Leigh Frame, PhD (LF):

Consumer Lab does a lot of supplement testing, typical purity, potency, sterility, those type of tests, and they had decades’ worth of data sitting around. And we thought, “Wouldn’t it be interesting to look over a large period of time to get an idea of what the whole industry is operating right like?” Because, if you only have a few supplements, it’s a little bit difficult to figure out what’s going on.


So, this [the Consumer Lab study] was looking over a large period of time with lots of different supplements to really get an idea of what’s going on in the industry. And what we found was many of them were rancid. These were products that were bought in the way that a consumer would buy them, from a store or Amazon, that sort of thing. They weren’t bought direct from the producer. So, if you just randomly buy a supplement off the market, the odds that you’re going to buy one that is rancid and thus not effective are pretty high.



LBM:

What’s turning so many supplements rancid, then?


LF:

Oxygen is the devil in terms of any type of oil, but especially omega-3s. They’re very sensitive to oxidation. You put them in your body, and they are reacting with free radicals and protecting you, and the same thing will happen in the environment. But, if they’ve done that, when you ingest them, they no longer are effective. So, the supply chain is certainly part of it. Storage is another part. Were they stored at room temperature? Were they stored at 80 degrees [Fahrenheit] outside? Was it humid? All of those things really add to this. But one thing that I think is really important is – how long were they sitting on the shelf? Has it been sitting on a shelf for a couple of years before you took it? All of those things can really add up. For the consumer, that’s probably the biggest concern – the freshness of the product. How long has it been there?


There are things you can do to potentially overcome that, ways that have better manufacturing processes, ways to have better packaging, ensuring that there’s a valid expiration date. So, it’s a little bit difficult to determine what that should be because it depends on the temperature. But here's what I tell people – you can test your own. So, you buy an omega-3 supplement, if you crack one open, and if it doesn’t smell good, then the product is not good. That’s a relatively easy hack to figure out if your product that you bought is OK. Now it’s fine, you have to do everything in your power to make sure it doesn’t get rancid, so perhaps keeping it in the fridge. Or a lot of people now are freezing their omega-3s and taking them frozen, because that actually helps with some of the fishy tastes and the GI [gastrointestinal] symptoms.



LBM:
Is it the case that this rancidity is being covered up by added flavorings?

LF:
That’s entirely possible. We can’t know for sure, because they [the flavorings] interfere with the testing for rancidity. 


LBM:

Does rancidity just affect oil-based supplements?


LF:

Yeah, it’s definitely all oil-based supplements. If you buy a vegetable oil off the shelf, it is likely to oxidize. And so, a lot of times these supplements will have antioxidants in them to prevent some of that, and that’s one method, but it’s really more of the handling and the storage, and some of that you can control. Once you’ve gotten it, you can take care of it, but, prior to that, you don’t have a lot of control over that. So, the best thing they can really do is be aware that this is an issue with oil supplements, and don’t stockpile a bunch of them; buy them directly from your supplier, and then take them immediately for, like, a period of 30 days.

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But the other thing is having a reputable supplier, which is unfortunately very difficult these days. Everybody gets everything on Amazon now, but who knows where Amazon’s getting it from? Is it coming directly from the manufacturer? In which case, that’s probably a great place to buy it, because you’re getting it very quickly. Or is it some third-party supplier that knows how quickly their product is turning over? 



LBM:
Should consumers be concerned? 

LF:

I think when people spend their money on supplements, they’re thinking of it as an investment. So, if you are buying a product that is not going to have the effect that you are investing in, I think they'll be very upset with that. They could be using their money elsewhere to get better effects, maybe actually eating fish, which I'd love to see them do.


And there’s some question whether there is even a health benefit with fish oil. What is the quality of the supplements? Are we delivering them in the right form? Do they have enough of the really quality omega-3 fatty acids?


If these supplements are high quality, contain the right things and you can maintain them in a way that keeps them fresh enough, then, yes, there’s probably benefits, but there are a lot of factors where this can go wrong. I think, for the consumer, it’s very frustrating to hear over and over again in the headlines that omega-3 is good for you, and then when they go out and buy a product, it might not actually be giving them the benefits, and they’re basically wasting their money.



LBM:

Is it the case, then, that eating fish conveys more health benefits than taking fish supplements? 


LF:
Very true, probably. With my nutrition science hat on, those studies of people eating fish, [I think] what were they not eating? Like, did they eat less red meat because they were eating more fish? That’s a very complex thing, and we wouldn't necessarily expect a pill to give you all of those benefits, but if there truly are omega-3 benefits – and, mechanistically, there’s tons of research – if you were able to get just some of that benefit with a supplement, it would be better for all these people that are not going to get the benefit, right? They’re not going to be eating fish to that level. It’s to supplement the diet.


LBM:
Regarding the rancidity, is anything going to change in the supplement industry? Does the industry need more regulation?

LF:

It's a great question. The FDA regulates supplements more like foods than drugs. Drugs have to be proven safe; foods and supplements are basically assumed to be safe until proven otherwise, which is not ideal, because what happens is we get these things out in the market, and then we find out people are getting sick, and then they get pulled off.


We’re seeing this right now with cinnamon. Cinnamon is getting pulled off the market left and right in the United States right now because we found that it has lead in it. But the only reason we found out that it had lead in it is because people were getting sick. We’re not routinely testing all the cinnamon brands on the shelf for lead. You could maybe argue that we should be, but we aren't, and part of that is just to do with the infrastructure out there.


We don’t have the governmental finances to be able to mandate that, and even if we did, the cost to the consumer would be really high. If you are requiring every cinnamon product or every fish oil product to be tested, then the cost of that product is going to go up. And you will actually see this in the supplement market right now; you'll see some companies charge quite a lot for their supplements, and you're like, “Well, it’s the same thing.” But that’s not what you’re paying for; you’re paying for the testing that they’re doing on the back-end and all the safety mechanisms that they’ve put into their system to make sure that it is safe and it isn't rancid. But most people don’t know that, and so they don't want to spend $80 on a supplement. They want to spend $10 on it, and they don’t understand why that’s not going to be the same thing.