Baby formula: missing key fats?

Baby Formula: Missing Key Fats?

Infant formula isn't just any old food. The nation learned that lesson the hard way in the late 1970s, and it may be about to learn it again. In 1978, a California-based company named Syntex accidentally left chloride out of its two formulas, Neo-Mull Soy and Cho-Free. As a result, hundreds of babies suffered from poor muscle control, delayed speech development, and slowed growth.

But the damage may not have ended there, says Carol Laskin, one of the parents who started an organization to represent the victims.

Now that the children are second-and third-graders, preliminary studies suggest that they are more likely than their peers to have learning disabilities and speech and language disorders. (1) "At each step where you need to do more abstract thinking, it seems that more kids shake out," says Laskins.

In 1980, spurred by the chloride disaster, Congress passed the Infant Formula Act, which mandates the Food and Drug Administration to see that formula contains all the nutrients that babies need.

But a growing body of evidence suggests that all of the formulas now on the market are missing an ingredient that babies may require for optimal health. And it may take years before the FDA requires (or even allows) the industry to add it to their products.

The parents of bottle-fed babies shouldn't panic. this isn't another Neo-Mull Soy. But even if the effects of this new deficiency are more subtle, and possibly reversible, they demand immediate attention...simply because it's formula.

"Infant formula has to be as good as possible because it is the sole source of norishment for a very fragile individual during peak brain development," says Laskin. "If your child weighs five pounds less, that's okay. If the brain doesn't develop properly, that isn't okay. The consequences last forever."

The Missing Hex. The ingredient now missing from infant formula is docosahexaenoic (doh-KOH-suh-HEX-uh-ee-NOH-ick) acid, or DHA, which is one of the two major omega-3 fatty acids found in the fish oils that may help prevent heart disease.

But DHA isn't just for hearts. It is one of the most prevalent fats in the human brain and the retina of the eye.

Nature seems to want babies to accumulate DHA. During the last half of pregnancy, the fetus holds on to more DHA than to other fats that it get s from its mother's bloodstream.

Human breast milk contains DHA. In fact, the milk from mothers of premature babies (who get less DHA before birth) has even more DHA than the milk from mothers of full-term babies.

Formula has no DHA.

"Our results and preliminary studies reported by others support an essential role for omega-3 fatty acids in normal eye and brain development," says Ricardo Uauy, of the University of Texas Southwestern Medical Center in Dallas.

While Uauy believes the evidences is strong enough to require DHA in infant formulas, other researchers do not. But they do agree on one point: formulas should at least contain linolenic acid, an omega-3 fatty acid that babies can convert, at least to some extent, to DHA. And several powdered formulas--Isomil, Similac, Gerber, amd Carnation--have virtually no linolenic acid.

"I'm concerned about powdered formulas without linolenic acid," says Susan Carlson, of the University of Tennessee in Memphis. "I don't think they should be sold."

Babies Are Our Business. Even though more mothers breast-feed now than in the 1950s and 1960s, the formula business is booming. In 1989, an estimated 60 to 70 percent of two-months-olds were bottle-fed. By four months of age, 75 to 80 percent are on the bottle. The numbers are even greater among low-income babies.

Infant formula comes either as a liquid or as a powder that has to be reconstituted with water. Liquid formulas are usually made with soybean oil, a good source of linolenic acid. (That's true of all brands, whether they contain milk or soy protein.)

Unfortunately, powdered Isomil, Similac, and Gerber formulas are made with coconut and corn oils, which contain little linelenic acid. What's more, corn oil is loaded with linoleic acid, which can impede an infant's ability to convert linolenic acid to DHA.

Abbott Lab's Isomil and Similac powdered formulas have no linolenic acid "because of the technical difficulty of adding it without rancidity," says company spokesperson Jed Weiner.

But Mead Johnson has recently found a way to add linolenic to its powdered Enfamil and Pro-Sobee, says spokesperson Holly D'Amour. "Our stability studies show no difference between Enfamil and Pro-Sobee with or without soy oil." Gerber's formula (which is made by Mead Johnson) still has no linolenic acid, but the company ways it expects to add it by the end of 1990.

Several small brands--Wyeth's S.M.A. and Nursoy and Carnation's Good Start--are not made with linoleic-rich corn oil, so they need less linolenic acid. S.M.A. and Nursoy probably have enough linolenic; Good Start probably should have more.

At Least Linolenic. Some of the strongest evidence that babies need linolenic acid was published years ago by Martha Neuringer and William Connor, of the Oregon Health Sciences Center in Portland.

"Monkeys that are deficient in all omega-3 fatty acids perform worse in terms of vision and behavior than monkeys fed formula that contains soybean oil," says Connor.

He and Neuringer found that 12-week-old monkeys fed a linolenic-acid-rich formula averaged about 20/45 vision, but monkeys fed no linolenic acid and extremely high levels of linolenic acid had only 20/90 vision. What's more, at the age of 21 months, the deficient monkeys' eyes took longer to recover from a bright flash of light. (2)

Now the question is whether babies can convert linolenic acid to DHA efficiently enough to meet their needs. In other words, is there enough evidence to require not just linolenic acid, but DHA, in formulas? So far, the experts disagree.

Do Babies Need DHA? Levels of DHA in red blood cells drop precipitously during the first months of life in babies fed linolenic-rich formula, but not in those fed breast milk or DHA-supplemented formula. (3), (4)

Still, low blood levels don't prove that babies require DHA. Scientists need evidence that DHA deficiency causes harm. And so far, they differ over whether that evidence is in.

In new, unpublished studies, researchers Uauy and Carlson have independently found that premature babies fed DHA-deficient, linolenic-containing formula have poorer vision six months after the date they should have been born than preemies fed DHA-containing formulas that companies have made available for experiments. (5), (6)

But questions remain:

* Do botle-fed babies catch up? "[DHA-containing fish] oil improves visual acuity and retinograms at four months, but by 9 to 12 months, there's no difference at all," says Carlson, who followed her infants longer than Uauy followed his.

Still, she adds, "these infants are probably deficient in [DHA] in the first six months. We could do better by them."

* Does DHA slow weight-gain? In Carlson's study, the preemies fed DHA-containing formula gained weight slightly more slowly. But Uauy calls her results "equivocal" for several reasons. One is that the DHA-supplemented babies didn't get arachidonic acid, another fat found in human milk.

It's also possible that something in the fish oil that was added to Carlson's formula--other than the DHA--slowed tha babies' growth. But that doesn'r deter Uauy, or even the more cautious Carlson. "I think DHA is important for development," she says. "We just haven't yet figured out the best way to put it into formula."

* Do only premature babies need DHA? So far, well-designed studies have only been done on preemies, who are at greater risk for omeg-3 deficiency. But Uauy has preliminary evidence that full-term babies also better if they're fed human milk rather than formula.

Babies Can't Wait. Despite its mandate to ensure that infant formula is as complete as possible, the FDA isn't moving fast enough on omega-3s.

"We're going to request that the American Academy of Pediatrics study the issue for us," says the FDA's John Wallingford. If the Academy decides that preemies do need linolenic acid or DHA, the FDA will then ask it about full-term babies.

But that could take years, especially if the Academy recommends adding DHA. Unlike soybean oil, DHA is not already on the Generally Recognized As Safe (or GRAS) list.

(When manufacturers asked the FDA for permission to add a non-GRAS nutrient--the amino acid taurine-to formula, the FDA took three years to act, even though human milk contains taurine. In the end, the agency decided not to officially respond, effectively approving the new ingredient.)

Meanwhile, tens of thousands of parents are buying powdered formulas that have no linolenic acid, when experts agree formulas should have DHA's precursor, if not DHA itself.

Oregon's William Connor believes that what babies eat during their first six months is critical, and that damage caused then can't be repaired later. How many infants will pass through those first six months before the FDA acts?

"The brain gets bigger right after birth," says Connor. "By the age of two, it's close to adult size. Man's future depends on what his food is as an infant."

(1) J. Pediatr. 115: 97, 1989.

(2) Proc. Nat. Acad. Sci. 83: 4021, 1986.

(3) Am. J. Clin. Nutr. 36: 106, 1982.

(4) Pediatr. Res. 21: 507, 1987.

(5) Pediatr. Res. 27: 292A, 1990.

(6) Pediatr. Res. 25: 285A, 1989.