2 years to 5 years

Focus on: Brain Development
"Simple choices that parents make early on have a profound effect on their child's brain development," says David Perlmutter, MD, FACN, who practices in Naples, Florida. Ensure that your child's brain and nervous system develop fully with these tips.

Know about brain food. A child's brain uses 225 percent more glucose than an adult's brain, says Perlmutter. And just like babies, toddlers and preschoolers need adequate amounts of DHA and iron to feed their hungry brains. These nutrients can come from food—DHA from fish; iron from green leafy vegetables or organ meat. However, because these foods often are not at the top of a 3-year-old's list of favorite chow, usually supplementation is warranted, Perlmutter says. Children ages 2 to 5 require 200 mg of DHA and 8 to 10 mg of iron daily, he says.

Avoid bad fats. Seventy percent of the brain is made up of fat, and the body builds its brain cells from the fats that are consumed, Perlmutter says. DHA speeds up the transmission of messages among the brain's neurons and "is vital for the formation of synapses, dendrites, and other important cells that support brain development," he says. But other fats—particularly trans fats found in processed foods, fast foods, and some frozen foods—actually interfere with normal cellular function, resulting in a slower, less efficient brain.

Eat organic. Kids who eat organic foods have six to nine times less exposure to toxic pesticides than children fed a conventional diet (Environmental Health Perspectives, 2003, vol. 111, no. 3). Pesticides, especially widely used organophosphates, are toxic to the developing brain and can impair concentration and increase hyperactivity in some children, says Perlmutter. Because pesticide residue is "stored in fat cells and remains in the body indefinitely," exposure in young children can be particularly toxic, he says. If you can't afford to buy all organic produce, choose organic at least for those foods higher in pesticides, including apples, spinach, bell peppers, cherries, celery, imported grapes, and strawberries.

Get the lead out. Chemical exposures are pervasive in the modern world, says Leo Trasande, MD, a pediatrician and researcher at Mt. Sinai Medical Center in New York. Lead, mercury, polychlorinated biphenyls (PCBs), and other toxins have been associated with cognitive and other neurological impairments in hundreds of thousands of children each year. Simple steps to limit children's exposure include testing your home for lead-based paint, inspecting plumbing systems for lead contamination, using only filtered or cold tap water for drinking and cooking (hot tap water is likely to contain higher levels of lead), and cleaning with only natural, nontoxic products. Perlmutter also recommends avoiding soft plastic toys, such as teething rings and bath toys made with polyvinyl chloride, which can contain lead, phthalates, and other toxins.

Choose safer fish. Fish, rich in DNA, is the ultimate brain food. Fish higher on the food chain can be contaminated by mercury and PCBs, says Trasande. Good choices include wild Alaskan salmon, tilapia from the United States or Central America, and northern U.S. and Canadian shrimp, according to www.kidsafeseafood.org, a website devoted to helping families make healthy seafood choices. Parents should also give their kids only those fish oil supplements that have been screened for—and are free of—mercury and other contamination.

Engage the brain. Most waking hours during the first five years of your child's life should be spent engaged in "brain-building endeavors" such as reading, musical training, or imaginative play, Perlmutter says. These activities teach the brain how to learn and stimulate "the neurons to make more connections, which will make the brain stronger, faster, more efficient, and ultimately smarter," he says. In comparison, watching lots of television—even educational programs—at an early age can actually dull the brain, making future learning more difficult, he adds.

Food sensitivities. Many children can have trouble tolerating a particular food such as dairy or gluten, though only a small number have actual food allergies. Food sensitivities can cause diarrhea, abdominal cramping, and other digestive ailments, but they have also been linked to more serious problems. Studies have shown that kids with gluten sensitivity, also known as celiac disease, are at greater risk for displaying symptoms associated with attention deficit hyperactivity disorder, or ADHD, says Perlmutter.

Be sun safe. Young kids, particularly those with fair complexions, produce less melanin, the skin's primary defense against the sun's harmful rays. So whether you're at the beach or on the ski slopes, make sure your children are wearing hats, sunglasses, and sunscreen. Choose an SPF 30 sunscreen formulated for children that protects against both UVB and UVA rays.

Watch for asthma. Childhood asthma has more than doubled since 1980 and now affects more than 10 percent of all children. In about half of these kids, the symptoms of asthma—wheezing, shortness of breath, and tightness in the chest—appear before age 5, Perlmutter says. If your child has asthma, Perlmutter recommends keeping him away from environmental triggers such as pollen, dust mites, tobacco smoke, and household chemicals; and limiting his exposure to stress, another asthma trigger. Some researchers believe that an inactive lifestyle—one that keeps children inside and exposed to indoor asthma triggers such as phthalates (which are added to many household products, including perfumes, beauty products, and children's toys)—may be partially to blame for the increase in childhood asthma.

Next page: 5 years to 10 years