make you think better. Should I take it?” He thrust in front of my face an advertisement for ginkgo root. Derived from the ginkgo tree, ginkgo biloba has been advertised for decades as a brain booster, improving memory in both young and old, even treating Alzheimer’s. These claims are testable. A number of researchers began to study gingko as they would any promising pharmaceutical. Sorry, I told the student. Ginkgo biloba does not improve cognition of any kind in healthy adults—not memory, not visual-spatial construction, not language or psychomotor speed or executive function. “What about old people?” my student asked. Nope. It doesn’t prevent or slow down Alzheimer’s, dementia, or even normal age-related cognitive decline. Other botanicals, like St. John’s wort (purported to treat depression) show similar impotence. My student left, crestfallen. “The best thing you could do is get a good night’s sleep!” I hollered after him.
Why is it that these nutrition myths can fool even bright kids like my student? First, nutrition research is really, really hard to do, and it is shockingly underfunded. The types of long-term, rigorous, randomized trials needed to establish the effects of food often go undone. Second, most foods we consume are very complex at the molecular level; wines, for example, can have more than 300 ingredients. It is often tough to discern what part of a food product is actually giving the benefit or doing the harm.
The way our bodies handle food is even more complex. We don’t all metabolize food exactly the same way. Some people can suck calories out of a piece of paper; some people wouldn’t gain weight if they inhaled milkshakes. Some people use peanut butter as their primary source of protein; others will die of an allergic reaction if they smell it on an airplane. To the eternal frustration of just about every researcher in the field, no single diet is going to work the same way for all people, and that’s because of this extraordinary individuality. This is especially true if you’re pregnant.
Neurons need omega-3s
So you can see why only two supplements thus far have enough data behind them to support an influence on brain development in utero. One is the folic acid taken around conception. The other: omega-3 fatty acids. Omega-3s are a critical component of the membranes that make up a neuron; without it, neurons don’t function very well. Humans have a hard time making omega-3s, so we have to outsource the materials to get them into our nerves. Eating fish, especially oily ones, is a good way to do it. Those of us who don’t get enough omega-3s, studies show, are at much greater risk for dyslexia, attention-deficit disorders, depression, bipolar disorder, even schizophrenia. Most of us get enough of the fatty acids in our regular diet, so it’s generally not a problem. But the data underscore a central fact: The brain needs omega-3 fatty acids for its neurons to function properly. Apparently, the Three Stooges knew this decades ago! (Larry: “You know, fish is great brain food.” Moe: “You know, you should fish for a whale.”)
If a moderate amount of omega-3s keeps you from being mentally disabled, does a whale-sized helping of it increase brain power, especially for the baby? Here the evidence is decidedly mixed, but a few studies indicate the question warrants further research. One Harvard study looked at 135 infants and the eating habits of their mothers during pregnancy. The researchers determined that mothers who ate more fish starting in the second trimester had smarter babies than those who didn’t. By smarter, I mean that the babies performed better on cognitive tests that measure memory, recognition, and attention at six months post-birth. The effects weren’t large, but they existed. As a result, researchers recommend that pregnant women eat at least 12 ounces of fish per week. What about the mercury in fish, which can hurt cognition? It appears that the benefits outweigh the harm. Researchers recommend that pregnant women eat those 12 ounces from sources possessing less concentrated mercury (salmon, cod, haddock, sardines, and canned light tuna) as opposed to longer-lived predatory fish (swordfish, mackerel, and albacore tuna).
My belly is evidence that I know how tough it is to eat properly, whether you are trying to control how much to eat, what to eat, or both. There’s Goldilocks again: You need enough, but not too much, of the right types of food. And the third factor usually doesn’t help.
3. Avoid too much stress
It was not a good idea to be in Quebec and pregnant around January 4, 1998. For more than 80 hours, freezing rain and drizzle fell relentlessly across eastern Canada—immediately followed by a steep drop in surface temperature. This meteorological one-two punch turned eastern Canada into ice hell. Under the weight of the freeze, more than a thousand towering metal power-line structures toppled like dominoes. Tunnels collapsed. Thirty people died. A state of emergency soon was declared; the army was called up. Even so, thousands of residents were without power for weeks, in freezing temperatures. If you were pregnant and could not get to a hospital for your regular checkups—God forbid if you went into labor—you were stressed out of your mind. And so, it turned out, was your infant. The effects of that storm could be seen on the children’s brains years later.
How do we know that? A group of researchers decided to study the effects of this natural disaster on babies in the womb—then follow the children as they grew older and entered the school system. The result was scary. By the time these “ice storm” children were 5, their behaviors differed markedly from children whose mothers hadn’t experienced the storm. Their verbal IQs and language development appeared stunted, even when the parents’ education, occupation, and income were taken into account. Was the mother’s stress the culprit? The answer turned out to be yes.
Maternal stress can profoundly influence prenatal development. We didn’t always think so. For a while, we weren’t even sure if mom’s stress hormones could reach her baby. But they do, and that has long-lasting behavioral consequences, especially if the woman is severely or chronically stressed in those hypersensitive last months of pregnancy. What kind of consequences?
If you are severely stressed during pregnancy, it can:
• change the temperament of your child. Infants become more irritable, less consolable.
• lower your baby’s IQ. The average decline is about 8 points in certain mental and motor inventories measured in a baby’s first year of life. Using David Wechsler’s 1944 schema, that spread can be the difference between “average IQ” and “bright normal.”
• inhibit your baby’s future motor skills, attentional states, and ability to concentrate—differences still observable at age 6.
• damage your baby’s stress-response system.
• shrink the size of your baby’s brain.
A review of more than 100 studies in various economically developed countries confirm that these powerful, negative effects on prenatal brain development are cross-cultural. David Laplante, lead author of the ice-storm study, said in a somewhat understated fashion: “We suspect that exposure to high levels of [stress] may have altered fetal neurodevelopment, thereby influencing the expression of the children’s neurobehavioral abilities in early childhood.”
Moderate vs. toxic stress
Is this stressing you out? Luckily, not all stresses are created equal. Moderate stress in small amounts, the type most women feel in a typical pregnancy, actually appears to be good for infants. Stress tends to get people moving, and we think that enriches the baby’s environment. The womb is a surprisingly hearty structure, and both it and its tiny passenger are well equipped to ride out the typical stressors of pregnancy. It is just not prepared for a sustained assault. How can you tell the brain-damaging stress from the typical, benign, even mildly positive stress?
Most toxic stresses have one common characteristic: you feel out of control over the bad stuff coming at you. As stress moves from moderate to severe, and from acute to chronic, this loss of control turns catastrophic. That can affect baby. Bad types of stress seem obvious once you know where
