Rice cereal has traditionally been the first complementary food given to American infants, but there is no good reason not to introduce meats, vegetables, and fruits as the first complementary foods.
Introducing these foods early and often promotes healthy eating habits and preferences for these naturally nutrient-rich foods, according to Dr. Frank R. Greer, who is a professor of pediatrics at the University of Wisconsin in Madison and also a member of the American Academy of Pediatrics's Committee on Nutrition.
“Complementary foods introduced to infants should be based on their nutrient requirements and the nutrient density of foods, not on traditional practices that have no scientific basis,” Dr. Greer said in an interview.
In fact, the AAP's Committee on Nutrition is working on a statement that will include these new ideas, Dr. Greer said in an interview. Currently, there are no official AAP recommendations for introduction of complementary foods, which are any nutrient-containing solid or liquid foods other than breast milk or formula given to infants, excluding vitamin and mineral supplements. By 6 months of age, human milk becomes insufficient to meet the requirements of an infant for energy, protein, iron, zinc, and some fat-soluble vitamins (J. Pediatr. Gastroenterol. Nutr. 2008;46:99–110).
Rice cereal has been the first complementary food given to infants in the United States for many reasons, including cultural tradition. By the 1960s, most U.S. infants (70%-80%) were fed cereal by 1 month of age. By 1980, rice cereal predominated, as it was considered to be well tolerated and “hypoallergenic”—given growing concerns about food allergies, he said.
However, newer thinking is that the emphasis for complementary foods should be on naturally nutrient-rich foods. This includes protein and fiber, along with vitamins A, C, D, and E and the B vitamins. In addition, saturated and trans fats should be limited, as should sugar, said Dr. Greer.
In light of this thinking, rice cereal is a less than perfect choice for the first complementary food given to infants. Rice cereal is low in protein and high in carbohydrates. It is often mixed with varying amounts of breast milk or formula. Although most brands of formula now have added iron, zinc, and vitamins, iron is poorly absorbed—only about 7.8% of intake is incorporated into red blood cells.
In contrast, meat is a rich source of iron, zinc, and arachidonic acid. Consumption of meat, fish, or poultry provides iron in the form of heme and promotes absorption of nonheme iron, noted Dr. Greer. Red meat and dark poultry meat have the greatest concentration of heme iron. Heme iron is absorbed intact into intestinal mucosal cells and is not affected by inhibitors of nonheme iron from the intestinal tract. Iron salts present in infant cereal are generally insoluble and poorly absorbed (with the exception of iron fumarate).
By 6 months, roughly a third of U.S. infants have been introduced to fruit (71%) and vegetables (73%), but only 21% have been introduced to meat. In a 2008 study in Pediatrics, researchers reported that 15% of infants have less than one serving of fruit or vegetable per day by 8 months of age (Pediatrics 2008;122[suppl. 2]:S91–7).
The early introduction of a variety of complementary foods is important for several reasons. Early experiences promote healthy eating patterns, said Dr. Greer. It's known that food flavors are transmitted to breast milk; infants whose mothers eat fruits and vegetables during lactation will have greater consumption of fruits and vegetables during childhood (Public Health Nutr. 2004;7:295–302). It's also been shown that infants are more accepting of food after repeated exposure (Am. J. Clin. Nutr. 2001;73:1080–5). Dr. Greer reported having no conflicts of interest.
Strategy Shifts on Allergenic Foods
Delaying or avoiding the introduction of allergenic foods during a critical window in the first year of life doesn't appear to prevent the development of food allergies and may even put children at increased risk, according to Dr. Greer.
There is a lack of evidence to support food allergen avoidance in infants, he said. Any benefits appear to be largely in the first 3–4 months of life, when exclusive breastfeeding is of the greatest benefit for prevention of atopic disease.
Oral tolerance is an antigen-driven process and depends on regular exposure to food antigens during an early window. Allergen avoidance may be unsuccessful or detrimental in allergy prevention in infants. There is some evidence that continued breastfeeding during new food introduction is beneficial in preventing atopic disease.
In 2008, the AAP recommended that complementary foods should not be introduced before 4–6 months and noted that there is no indication that delayed introduction of certain foods, including allergenic foods such as wheat, fish, egg, and peanut-containing products, protects against atopic disease (Pediatrics 2008;121:183–91).