(CNN) -- When people find out I'm a dietitian, they often ask me what not to eat. I often find myself trying to gracefully redirect the topic. Although it's true Americans eat too much of various types of food, a fixation on risk and avoidance seems to have eclipsed efforts to eat wholesome, delicious foods.
The fixation on risk is especially heightened when it comes to nutrition during pregnancy.
A May 2009 article in the Journal of Reproductive Medicine said, "Avoidance of toxins during pregnancy is paramount to the proper development of the fetus and infant." The article explored how much seafood pregnant women eat and highlighted data from the Medical University of South Carolina that showed nearly a third of pregnant women surveyed said they never ate fish.
The U.S. Food and Drug Administration recently found the average expectant mother in the U.S. eats 1.89 ounces of seafood a week, less than half of a serving.
Seafood is one of the only naturally rich sources of a special kind of healthful omega-3 fat called docosahexaenoic acid, or DHA, that is vital to normal brain development. "Without adequate amounts of these fatty acids," advises the Food and Agricultural Organization of the United Nations, "normal brain development does not take place."
This year, the U.S. Department of Agriculture recommended that mothers-to-be eat seafood during pregnancy and set guidelines that, for the first time ever, include a minimum amount -- at least 8 and up to 12 ounces of seafood per week, from choices that are lower in methylmercury. Pregnant women are advised not to eat uncooked protein of any kind, so no sushi.
The USDA said that "moderate evidence indicates the omega-3 fatty acids, in particular DHA, from at least eight ounces of seafood per week" for expectant and breast-feeding mothers is associated with "improved infant health outcomes, such as visual and cognitive development." In other words, starting in the womb, fish is brain food.
Why do people eat so little seafood despite calls to eat more, especially during pregnancy? The science of seafood and pregnancy has been misunderstood for many years, partially because of confusion over 2004 FDA advice.
That FDA wanted to communicate three simple recommendations for expectant moms:
1. Eat up to 12 ounces of seafood a week, of which 6 ounces can be albacore tuna.
2. Avoid four higher-mercury species -- shark, swordfish, tilefish and king mackerel.
3. Check local guidance for eating recreationally caught fish.
But pregnant women, and other groups not targeted by FDA, hear "eat less fish."
A Harvard study published last year showed that, among several focus groups of pregnant women from Boston, no one received encouragement to eat fish from their doctors, but many moms-to-be were told to limit seafood consumption.
Recently, another concern has grabbed attention -- the risk of eating fish from Japan. The FDA announced it is taking precautions to ensure foods entering the U.S. are safe -- including screening seafood. It's important to remember that less than one tenth of 1 percent of the seafood Americans eat comes from Japan.
Maybe redirecting my nutrition conversations, and the nationwide nutrition conversation, away from risk isn't the answer. If people want to talk about risk, then let's talk about risk. A fish- and omega-3-deficient diet can introduce heart disease, dementia, macular degeneration and suboptimal brain development.
Education, understanding and perspective, not hand-wringing and hyperbole, drive consumers to make informed choices about seafood and nutrition.
The opinions expressed in this commentary are solely those of Jennifer McGuire.