If you spend much time reading Internet blogs or nutrition Web sites, you may think that omega-3s are a cure-all! Alternatively, if you read nutrition news as soon as it comes out, you may conclude omega-3s don’t do anything at all! What is the truth?
That question isn’t easy to answer. Omega-3 fatty acids are simply a type of fatty acid with more than one double bond with the first double bond occurring at a special position on the fat. That means that omega-3s are liquid fats (that is, oils) found in plant foods such as flax, soy and leafy greens and in animal foods such as fatty fish.
They have been claimed to fix problems as diverse as heart disease, rheumatoid arthritis and even autism and ADD! However, a recent large study published in the Journal of the American Medical Association found no benefit to omega-3 supplements in lowering risk of heart disease, stroke, or cardiac events.
Another review of research published in December showed that there were no studies of sufficient quality to even include in a review of the effects of omega-3s on developmental disorders such as ADD or autism. These studies have had problems such as small sample size, offering very different doses in each study, lack of a control group or a very short follow-up time. The number and quality of studies done in children are many times fewer than those done in adults. Yet, many parents swear by the effectiveness of omega-3 supplements for their kids.
Right now, we can say that there seems to be good evidence that consuming fatty fish may reduce triglycerides (a type of fat in the blood) and may reduce risk of cardiovascular disease. There is also a little bit of evidence that omega-3 fatty acids may help reduce behavioral symptoms of ADD and ADHD and may improve insulin sensitivity (that is, could reduce risk of diabetes).
For adults, experts recommend a combined 500 mg daily of EPA and DHA (two omega-3s found in fish) to reduce cardiac risk or up to 1000 mg per day for those with heart disease already. Recommendations for kids are harder to come by. The Food and Nutrition Board of the National Institutes of Medicine has set 700 mg per day of omega-3 as a level of adequate intake (AI) for 1-3 year olds. 900 mg is considered adequate for 4-8 year olds and 1200 mg for 9-13 year olds.
Because many studies have shown a benefit to eating fatty fish and fewer have shown that taking supplements is helpful, let’s start with food. A 3 oz portion of the following fish could provide the recommended amounts: striped bass (800 mg), herring (1800 mg), salmon (900-1800 mg), Atlantic mackerel (1000 mg), sardines (1400 mg), trout (800-1000 mg), bluefin tuna (1300 mg). Vegetable sources of omega-3 such as flaxseed, soy, walnuts, and chia seeds may have some benefit, but they do not contain the same type of omega-3 fat and may not have the same benefits.
Many folks worry about the possibility of mercury contamination in fish, a particular concern when feeding children. A large study several years ago found that the health benefits of consuming fish probably outweigh the risks; however, one still needs to be careful to consume safe sources of fish and those with likely high levels of contamination. To avoid excess mercury in fish, avoid eating shark, swordfish, king mackerel, and tilefish (golden snapper). Also avoid feeding your kids more than about 6 oz a week of fish (twice weekly).
Sustainable sources of fish for our area according to the Monterrey Bay Aquarium which are also high in omega-3s include Spanish and Atlantic Mackerel, Alaska wild salmon, striped bass, farmed US rainbow trout, and US Bigeye Atlantic tuna.
When cooking fish for your kids, remember that eating more baked and broiled fish is associated with improved health outcomes. Eating more fried fish is associated with worse indicators of heart health.
If you do choose a supplement for your child, avoid liver oils. These can be excessively high in vitamin A and vitamin D and could contain environmental contaminants. Instead look for ultra-pure supplements which are free of mercury. Some high quality products which provide the recommended levels of omega-3s include Nordic Naturals Ultimate Omega-Junior soft gels with 325 mg EPA and 225 mg DHA in 2 soft-gels, Nordic Naturals 3-6-9 Junior liquid with 338 mg EPA and 225 mg DHA in ½ teaspoon of liquid, and Coromega-3 Kids Squeeze with 350 mg EPA and 230 mg DHA per packet. All omega-3 gummies on the market are too low in omega-3s to be of benefit.
Chowdhury. BMJ. 2012.
Gebauer. AJCN. 2006
Mozaffarian. Am J Cardiology. 2006
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Kathleen Davis is an outpatient dietitian at Cook Children’s Medical Center.