Fish Allergies and Omega-3 Supplements

woman holding fish oil supplement and water
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I'm sure you've seen this advice: "Eat fish — it's heart-healthy!" But how can you get those important health benefits if you're allergic to fish?

The heart-healthy benefits of fish are mainly in the oil. The American Heart Association recommends regular consumption of two types of fat known as omega-3 fatty acids — DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid) — that are found in particularly high concentrations in fatty fish like herring, trout and sardines.

People who don't eat fish due to a simple aversion have the option of taking omega-3 fish oil supplements.

But for people who are allergic to fish, that may not be an option, although research and medical opinion is mixed.

For example, one very small study involving six people who were allergic to finned fish concluded that those people handled fish oil supplements without any allergic reaction.

However, a case report in the medical literature involving a woman with documented seafood allergy found that she suffered from severe allergy symptoms — swelling, shortness of breath and chest tightness — after having taken prescription fish oil capsules. Her symptoms abated within five days of throwing out the fish oil, which she did after a trip to the emergency room.

Most fish oil supplement makers do (prudently) recommend against consuming the pills if you're allergic to fish. Fortunately, those who are allergic to fish have other options to get their omega-3 fatty acids.

How to Get Omega-3s If You're Allergic to Fish

Several vegetarian options do exist for omega-3 supplements. These include flaxseed oil, hemp oil and algae.

However, you should be aware that the human body does not use the omega-3 fatty acids in plant sources as efficiently as those in seafood. Micro-algae supplements, like spirulina, are considered the most efficient sources of DHA, which the body can convert to EPA.

If your doctor has recommended omega-3 supplements for any reason, you should mention your fish allergy and ask if she considers vegetarian supplements equivalent for your purposes.

For example, she may recommend a particular type of vegetarian omega-3 supplement, she may want to adjust your recommended dosage, or she might suggest that you adjust your diet to include certain foods that are naturally high in these fatty acids.

Supplemented Foods: Read Your Labels

More and more, unlikely foods are being touted as including heart-healthy omega-3 fats. Whenever you see this claim on a package, read the label closely to ensure that the source of the omega-3's in the food is not fish. Foods that are often supplemented in this manner include margarine, cereal and juices.


David BC et al. Achieving Optimal Essential Fatty Acid Status in Vegetarians: Current Knowledge and Practical Implications. American Journal of Clinical Nutrition. Sept. 2003. 78(3): 640S-646S. 17 May 2008.

Howard-Thompson A et al.

Flushing and pruritus secondary to prescription fish oil ingestion in a patient with allergy to fish. International Journal of Clinical Pharmacy. 2014 Dec;36(6):1126-9.

Mark BJ et al. Are fish oil supplements safe in finned fish-allergic patients? Allergy and Asthma Proceedings. 2008 Sep-Oct;29(5):528-9.

Surette, ME et al. The Science Behind Omega-3 Fatty Acids. Canadian Medical Association Journal. Jan. 2008. 178(2): 177-80.

Van Horn, L et al. The Evidence for Dietary Prevention and Treatment of Cardiovascular Disease. Journal of the American Dietetic Association. Feb. 2008. 108(2): 287-331.

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