 A number of so-called case control studies like this one have found that giving kids coddle of oil supplements may increase their risk of asthma later in life. Case control studies are done by asking about past behavior in cases, those with asthma, versus controls, those without asthma, to see if certain past behaviors are more common among the disease group. The problem is you're asking people to remember what they were doing years ago, and most people can't remember what they had for breakfast last week. And you can't rule out something called reverse causation. Maybe coddle of oil didn't lead to the asthma. Maybe the asthma led to the use of coddle of oil. So be nice to see a cohort study. You take people without asthma at the beginning, and you see if those that you know are taking coddle of oil are more likely to develop it. That gets around the problem of recall bias and reverse causation. And here it is. 17,000 people free of asthma. We know who's taking coddle of oil and who isn't. And then we see who gets asthma over the next 11 years. And they indeed found coddle of oil intake was significantly associated with the development of asthma. They think it may be the excessive vitamin A in the coddle of oil that was causing the problem, but there are a number of things in fish oil we may not want our children exposed to. Researchers recently looked at 13 over-the-counter children's dietary supplements containing fish oil to assess potential exposure to PCBs, toxic industrial pollutants that have contaminated our oceans. These were detected in all products. Could you just stick to the supplements made from the small short-lived fish like anchovies instead of big predator fish like tuna, or use the purified fish oils? No. They found no significant difference in PCB levels between the supplements labeled as molecularly distilled, or however high up the food chain the fish were. So while children's dietary supplements containing the long-chain omega-3s from fish oils may claim to benefit young consumers, daily ingestion of these products may provide a vector for contaminant exposure that may offset the positive health effects. What positive health effects are they talking about? Well, infants given DHA, fortified formula, may have better development of their eyes and brains compared to infants getting non-DHA, fortified formula. DHA is one of these long-chain omega-3 fatty acids. But what was the source of the DHA? Not fish. It was algae-derived DHA, so you can get the benefits of the omega-3s without the contaminant risks. Of course, breast milk is the gold standard. Significantly better than either of the formula-fed infants. So the best source of omega-3s is mom.