Interesting Psychology Team
2. Baby Brain Development Food
Women have strange experiences with food preferences during pregnancy, suddenly loving foods they used to loathe and loathing foods they used to crave. It’s not just pickles and ice cream, as any pregnant woman can tell you. One woman developed a craving for lemon juice on a burrito—a need that lasted for three months.
Another wanted pickled okra. A surprising number crave crushed ice. Women can even desire things that aren’t food. An item that regularly makes the Top Ten List of Weird Pregnancy Cravings is baby talcum powder. So is coal. One woman wanted to lick dust. Pica is a common disorder: a craving lasting longer than a month for eating things that aren’t food, like dirt and clay.
Is there any evidence you should pay attention to these cravings? Is the baby telegraphing its nutritional needs? The answer is no. There is some evidence that iron deficiencies can be consciously detected, but the data are thin. Mostly it’s a matter of how a person uses food in her daily life.
An anxious person who is comforted by the chemicals in chocolate might grow to crave chocolate whenever she feels stressed. And a woman will feel stressed a lot during pregnancy. (This craving for chocolate reflects a learned response, not a biological need, though I think my wife would probably disagree.) We actually don’t know why a pregnant woman’s crazy cravings occur.
That doesn’t mean the body doesn’t have nutritional needs, of course. The pregnant mom is a ship with two passengers but only one galley. And we’re looking to stock this kitchen with the right ingredients for brain growth. Of the 45 nutrients known to be necessary for growth of the body, 38 have been shown to be essential for neurological development. You can look on the back of most pregnancy-formulated vitamin supplements to see the list. We can look to our evolutionary history for some guidance on what to eat to get these nutrients.
Since we know something of the climate through which we developed for millions of years—one that supported ever-increasing brain girth—we can speculate about the type of foods that helped it along.
Caveman cuisine
An old movie called Quest for Fire opens with our ancestors seated by a fire, munching on a variety of foods. Large insects buzz about the flames. All of a sudden, one of our relatives shoots out his arm, clumsily grabbing an insect out of thin air. He stuffs it into his mouth, munches heartily, and continues staring into the fire. His colleagues dig around the soil for tuberous vegetables and scrounge for fruit in nearby trees later in the movie.
Welcome to the world of Pleistocene haute cuisine. Researchers believe that for hundreds of thousands of years, our daily diet consisted mostly of grasses, fruits, vegetables, small mammals, and insects. Occasionally we might fell a mammoth, so we would gorge on red meat for two or three consecutive days before the kill spoiled.
Once or twice a year we might get sugar, running into a beehive, but even then only as unlinked glucose and fructose. Some biologists believe we are susceptible to cavities now because sugar was not a regular part of our evolutionary experience, and we never developed a defense against it. Eating this way today (well, except for the insects) is called in some circles the paleo diet.
So, it’s a bit boring. And familiar. Eating a balanced meal, with a heavy emphasis on fruits and vegetables, is probably still the best advice for pregnant women. For the non-vegetarians in the crowd, a source of iron in the form of red meat is appropriate. Iron is necessary for proper brain development and normal functioning even in adults, vegetarian or not.
Miracle drugs
There is a lot of mythological thinking out there about what you should and should not eat—not just during pregnancy but your whole life long. I had an honors student at the University of Washington, the thoughtful type of kid who has to sit on his hands not to answer a question. One day he came up to me after class, breathless. He was taking an entrance exam for medical school and had just found out about a“miracle” drug.“It’s a neurotonic!” he exclaimed.“It improves your memory. It’ll 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 bilobahas 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 or dementia. It can’t even affect 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 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, so far, only two supplements 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 critical components of the membranes that make up a neuron; without it, they don’t function very well. Humans have a hard time making omega-3s, so we have to out-source the materials to get them into our nerves.
Eating fish, especially oily ones, is a good way to do it. If you don’t get enough omega-3, studies show, you 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.”)
So, if a moderate amount of omega-3 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 babies who 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 (sword-fish, mackerel, and albacore tuna).
I certainly know that eating properly is tough, whether you are trying to control how much you eat, what you 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.
