If you’ve turned on the TV lately, you’ve probably seen the commercial for Enfagrow Toddler Next Step, a new powdered drink made by formula manufacturer Enfamil. The advertisement starts with a close-up of a puzzle missing a single piece, cuts to an adorable toddler doing said puzzle, and hits you with this nail-biter: “Is something missing from your toddler’s nutrition?” The voiceover lady goes on to explain that your child is probably not getting enough of the omega-3 fatty acid DHA (docosahexaenoic acid), “an important nutrient that can help nourish the brain.” In fact, she says, “toddlers only get about 25 percent of the amount of DHA many experts recommend.” Luckily, Enfagrow can fill that gap!
Do toddlers need those supplements? Parenting magazine explains that DHA “jump starts the production of a hormone that’s crucial for brain development” for infants and toddlers. BabyCenter recommends omega-3 supplements for kids who don’t eat fatty fish at least once a week (and no, store-bought fish sticks don’t count). On the other hand, the Cornucopia Institute, a nonprofit organization that supports sustainable and organic agriculture, published a report in 2010 in which it warned that the omega-3 fatty acids added to infant and children’s drinks are “dangerous and unnecessary” and can cause diarrhea, rashes, and even seizures. So what’s the deal—are omega-3 supplements critical or harmful?
It seems that the answer to this question is a reassuring neither. Although omega-3 fatty acids such as DHA are important building blocks for the developing brain, and average consumption by American kids these days is quite low, there is little evidence to suggest that children become smarter or healthier when they take omega-3 supplements. In fact, there’s no clear consensus on how many omega-3 fats kids actually need. Most scientists and doctors agree, too, that it’s smarter to get nutrients through whole foods when possible—so if you want to engineer a nutritionally perfect toddler, feed her omega-3–rich salmon (among other things), not supplements. If, however, she prefers to throw her seafood than to eat it—in other words, if she isn’t getting any omega-3s from her diet and you can’t do anything about it—supplements can’t hurt. After taking a close look at the evidence, I’m confident that the safety concerns raised about the omega-3s added to formulas and kids’ drinks are not based in solid science.
First, some background on why there’s so much hype about these fats. Our bodies can’t make omega-3 fatty acids from scratch. We can make some DHA and EPA (eicosapentaenoic acid, another important omega-3 fat) from the precursor ALA (alpha-linolenic acid, an omega-3 fat found in walnuts and flaxseeds), but we do so very inefficiently. As a result, it’s best to get DHA and EPA directly from fatty fish, their most concentrated source. These fats are what you might call good fats—they don’t make us fat, but rather, they help our bodies, and particularly our brains, function properly. About 15 percent of the fat found in the brain is DHA, where the molecule helps brain cells function and react quickly. Omega-3s are also used to build parts of the eye, to maintain proper cell structure throughout the body, and to make hormones known as eicosanoids, which are important for a range of physiological functions both in the brain and elsewhere. Animals who are fed omega-3–deficient diets end up with learning and visual problems; some studies have also found associations between abnormal fatty acid levels in children and behavioral or developmental problems such as ADHD, autism, and reading and memory difficulties.
But before you run out to stock up on Enfagrow, there are some important caveats to consider. Just because fatty acid deficiencies have been linked to developmental problems doesn’t mean that the deficiencies cause the problems. In fact, researchers studying these links theorize that kids with developmental disorders or cognitive problems may have trouble metabolizing fatty acids—in other words, the disorders may cause omega-3 deficiencies, not vice versa. Supporting this notion, several studies and systematic reviews have shown that giving kids with these disorders omega-3 supplements does not improve their symptoms. Also, some studies have found higher than normal levels of certain fatty acids in kids with developmental problems.
Overall, there’s no good evidence to suggest that children who take omega-3 supplements fare better than those who don’t. I said “good evidence” because there are indeed some studies suggesting that kids who consume more omega-3s have better cognitive skills, but these are mostly observational or cross-sectional studies, which can be fraught with problems. Some analyze fatty acid levels in kids at a single point in time and compare these measurements to parent- or teacher-reported behaviors to see if low fatty acid levels correlate with poor behavior, but a single blood measurement may not accurately reflect a child’s usual omega-3 intake; plus, parental behavior reports are often biased. Other studies compare kids who happen to consume more omega-3s with kids who happen to consume less, but these kids often differ in many ways. They eat different diets overall, have different parents, live in different neighborhoods. If my son has higher blood DHA levels than similarly aged little boys who are growing up below the poverty line, it’s not the fatty acids that explain why he is more likely to go to college.
Some experts also cite breastfeeding statistics as evidence that the more omega-3 fats our kids get, the better they fare. Breastfed kids have historically scored higher on cognitive tests than have nonbreastfed kids, and breast milk contains more omega-3s than regular formula does. But does this mean that the extra omega-3s in breast milk are driving this cognitive edge? Again, no: There are many differences between breastfed and nonbreastfed children, and it’s very difficult to properly control for these factors, even though some studies try. One cleverly designed 2006 study found that, after carefully controlling for the mother’s IQ—apparently, on average, breastfeeding moms are smarter—there is no evidence that breast milk itself boosts intelligence. (Also, most infant formulas are now fortified with extra DHA anyway.)