SPECIAL REPORT Nutrition Vol. 13, No. 3, 1997

What We Eat May Determine Who We Can Be

We’ve long recognized the impact of diet on the body. It is commonly accepted that dietary fat composition affects the heart and other organs and that improved diet makes stronger, healthier people. Now let’s turn our attention to the brain. Radi- cal as it may sound, the notion that diet may affect intelligence and behavior should not be strange.

The one thing most people think they need to know about diet is that less fat is better than more. But there are many different kinds of fats with many different functions. The brain, for example, consists of 60% structural fat, and a fatty acid known as DHA (docosahexaenoic acid) is the most abundant component.

In May 1996, I asked pediatricians and neonatologists in the United States to join me in urging the Food and Drug Administration (FDA) to apply the principle that breast milk is the best and safest form of nutrition for infants and that formulas should emulate it. I also took the opportunity to make them aware that DHA and another fatty acid known as ARA (arachidonic acid) are important examples of this principle.

The occasion was a review of infant nutritional needs in order to recommend how they should be reflected in the level of nutrients in term infant formulas. My letter, reprinted in the May, 1996 issue of Nutrition (Vol. 12, No. 5), apparently struck a chord. The response was strong and passionate. More than 1000 pediatricians wrote me, each conveying a deeply personal and heartfelt message typified by the following:

As a pediatrician who cares for many low-income (and, unfortunately, mostly formula-fed) infants, and as a nullip- arous adoptive mother (i.e., my own children depend on infant formulas), I wholeheartedly agree with you that infant formulas should simulate breast milk as closely as possible. Breast-feeding is clearly the best infant feeding method, but when it can’t be used, then we owe it to our children to give them the very best substitute we can.

DHA is essential for brain and eye development, and ARA is associated with immune function and infant growth. As the most prevalent long-chain fatty acids (over 20 C) in human breast milk, they provide yet more reasons why mothers should breast-feed. Thus, my new devotion is an extension of my long-standing one. But just because children are not breast-fed doesn’t mean they shouldn’t have every possible nutritional advantage. That’s why formulas should match as closely as possible the composition of human breast milk, and DHA and ARA should be included.

The FDA review concerns infant nutritional needs and for- mula “requirements,” and it will take time. But there is no reason why the addition of DHA and ARA to infant formulas must wait. We have all the evidence we need to support inclu- sion: DHA and ARA are natural components of human milk, they are safe and available in natural food forms that closely mimic those found in human milk, and clinical data verify their importance when added at human milk levels. An expert

committee convened by the World Health Organization and Food and Agriculture Organization has concluded that DHA and ARA should be included in infant formulas for both preterm and full-term infants, and other scientific and clinical bodies have come to similar conclusions. Following routine FDA prod- uct approval procedures, they could be added now.

In fact, delay is costly. After birth, babies who are breast-fed continue to receive DHA from their mother’s breast milk at a time when significant brain growth is taking place, but formula- fed infants who are not supplemented with DHA are deprived of this important building block. To illustrate incalculable quality- of-life issues with limited conventional cognitive test standards, I refer to studies indicating that for every year of delay, more than 2 million formula-fed full-term babies born annually in the United States may experience a disadvantage of 3 to 6 IQ points compared with breast-fed full-term babies (the difference is even greater for low birth weight infants). Meanwhile, DHA is already in some European and Asian formulas.

I am often asked what difference a few IQ points make. At the least, they measure how someone performs on an IQ test. At most, they are a relative measure, among others, of individual potential. At three o’clock in the morning when I can’t sleep until I come up with just the right word for an article, I would give almost anything for some additional IQ points. And, if someone offered them to me at any time, I wouldn’t refuse- it can’t hurt-because in my lifetime, society has become in- creasingly complex. Three IQ points may not mean as much to one person as they do to another, and it may be difficult to measure the difference from person to person, but indications are that social economic consequences and costs across the entire society are enormous.

There are a number of things that can be done now. Encourage breast-feedi& DHA and ARA provide yet another powerful reason to breast-feed. As such, they should be used to encourage breast-feeding, particularly among those groups whose nutritional needs are not be- ing adequately met but whose incidence of breast-feed- ing-uniquely designed to satisfy infant nutritional needs-is frighteningly low. Improve dietary DHA intake for both mother and child. During pregnancy, DHA is transferred to the developing infant through the placenta. The highest rate of transfer occurs in the last trimester, the period of most rapid brain growth. After birth, DHA is rechanneled into breast milk so the infant can obtain the DHA necessary for the sig- nificant brain development that continues to occur during the first 12 mo of postnatal life.

But DHA dietary levels in the United States have dropped over the last 50 y as a result of a decline in dietary sources such as eggs and animal organs. DHA levels in the breast milk of U.S. women are among the lowest in the world.

To assure their babies have enough DHA, pregnant and nursing women should consider taking DHA supplements

Nutrition 13:220-221, 1997 OElsevier Science Inc. 1997 Printed in the USA. All rights reserved. ELSEVIER

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SPECIAL REPORT 221

(which are available) and/or following a diet rich in DHA sources like seafood or eggs (for many, eggs raise a concern about cholesterol intake). Studies show that DHA supplementa- tion of pregnant and lactating women increases DHA available to the fetus and the nursing baby. DHA supplementation not only helps assure that women have an adequate supply of DHA for their babies, it also helps replenish their own store of DHA, which is depleted by the developing infant during pregnancy.

3. Urge formula manufacturers to add DHA and ARA. For babies who are not breast-fed, commercially available infant formulas are their only nutritional option. Al- though several leading formula manufacturers have the right to include supplemental DHA and ARA, which are available in some European formulas, infant formula sold in the United States is not currently supplemented with DHA or ARA. And, adding them does not depend on the FDA to conclude its review of infant nutritional needs and formula requirements.

4. Encourage the U.S. Women, Infants and Children (WIC) and other government-subsidized infant nutrition pro- grams worldwide to demand formulas with DHA and ARA. Of the governmental programs affecting the future of the United States, the WIC program is arguably the most important because of its impact on infant nutrition (arguably one of the most important things any govem- ment program can do). WIC buys infant formula for disadvantaged children. As such, it is the largest infant formula purchaser in the United States. Thus, while all of us could use a bit more DHA, the predominant share of formula-fed infants who are deprived of this important building block comes from among those groups who can

least afford it-those whose nutritional needs are not adequately met but whose incidence of breast-feeding, uniquely designed to satisfy infant nutritional needs, is frighteningly low compared with other groups.

5. Consider the strategic implications of DHA on human potential. Make the relationship between DHA supple- mentation and cognitive and behavioral development a national priority. Develop nutrition policy, raise aware- ness, and expand research through the National Institutes of Health, organizations with infant and general nutrition responsibilities, and analogous bodies worldwide. Indo- nesia has begun such an effort.

The average American’s diet is low in DHA resulting from the decline over the last 50 y of dietary sources such as animal organ meats and eggs. The health benefit of reducing saturated fats from these sources is generally accepted, but along with the reduction of “bad” fats, “good” fats like DHA have been reduced, too. It may be no coincidence that the incidence of depression, attention deficit hyperactivity disorder, and aggres- sion has risen over that same period of time. Studies have correlated low levels of DHA with each of these conditions. What we don’t yet know is whether there is a connection. Are low levels of DHA the cause?

First, we must answer the question, “Is it what we eat?” (After all, it is what we are.) Then we can begin to understand who we can be.

FRANK A. OSKI, MD Distinguished Professor of Pediatrics

Former Chairman of Pediatrics Johns Hopkins University School of Medicine

Baltimore, Maryland, USA