A century ago, babies who couldn't be breast-fed usually didn't survive. Today, although breast-feeding is still the best nourishment for infants, infant formula is a close enough second that babies not only survive but thrive.
Commercially prepared formulas are regulated by the Food and Drug Administration.
The safety of commercially prepared formula is also ensured by the agency's nutrient requirements (see "Nutrient Requirements") and by strict quality control procedures that require manufacturers to analyze each batch of formula for required nutrients, to test samples for stability during the shelf life of the product, to code containers to identify the batch, and to make all records available to FDA investigators.
The composition of infant formula is similar to breast milk, but it isn't a perfect match, because the exact chemical makeup of breast milk is still unknown.
Human milk is very complex, and scientists are still trying to unravel and understand what makes it such a good source of nutrition for rapidly growing and developing infants. However, John C. Wallingford, Ph.D., an infant nutrition specialist with FDA's Center for Food Safety and Applied Nutrition, notes that "infant formula is increasingly close to breast milk."
More than half the calories in breast milk come from fat, and the same is true for today's infant formulas. This may be alarming to many American adults watching their intake of fat and cholesterol, especially when sources of saturated fats, such as coconut oil, are used in formulas. (In adults, high intakes of saturated fats tend to increase blood cholesterol levels more than other fats or oils.) But the low-fat diet recommended for adults doesn't apply to infants.
"Infants have a very high energy requirement, and they have a restricted volume of food that they can digest," says Wallingford. "The only way to get the energy density of a food up is to have a high amount of fat."
While greater knowledge about human milk has helped scientists improve infant formula, it has become "increasingly apparent that infant formula can never duplicate human milk," write John D. Benson, Ph.D, and Mark L. Masor, Ph.D., in the March 1994 issue of Endocrine Regulations. "Human milk contains living cells, hormones, active enzymes, immunoglobulins and compounds with unique structures that cannot be replicated in infant formula."
Benson and Masor, both of whom are pediatric nutrition researchers at infant formula manufacturer Abbott Laboratories, believe creating formula that duplicates human milk is impossible. "A better goal is to match the performance of the breastfed infant," they write. Performance is measured by the infant's growth, absorption of nutrients, gastrointestinal tolerance, and reactions in blood.
Wallingford agrees, explaining that while FDA's regulations on what goes into infant formula are to ensure there are enough nutrients, "that's just a starting point. What's really important is how infants thrive."
Cow's Milk or Soy?
Normal, full-term infants should get a conventional cow's-milk-based formula, says John N. Udall Jr., M.D., chief of nutrition and gastroenterology at Children's Hospital of New Orleans. However, adverse reactions to the protein in cow's milk formula or symptoms of lactose intolerance (lactose is the carbohydrate in cow's milk) may require switching to another type of formula, he says.
Symptoms that may indicate an adverse reaction to cow's milk protein include vomiting, diarrhea, abdominal pain, and rash. With lactose intolerance, the most common symptoms are excessive gas, abdominal distension and pain, and diarrhea. Since some of the symptoms overlap, a stool test may be necessary to determine the culprit. Usually, lactose intolerance will produce acidic stools that contain glucose. If the protein is the problem, stools will be nonacidic and have flecks of blood.
The main alternative to cow's milk formula is soy formula. About 20 percent of the formula sold in the United States is soy. "Lactose intolerance is probably the biggest reason to switch to soy formula," says William J. Klish, M.D., chairman of the American Academy of Pediatrics Committee on Nutrition.
The carbohydrates in most soy formulas are sucrose and corn syrup, which are easily digested and absorbed by infants. However, soy is not as good a protein source as cow's milk. Also, babies don't absorb some minerals, such as calcium, as efficiently from soy formulas. Therefore, according to the American Academy of Pediatrics, "Healthy full-term infants should be given soy formula only when medically necessary."
For a child who can't tolerate cow's milk protein, Klish recommends the use of hydrolyzed-protein formula. Although hydrolyzed-protein formulas are made from cow's milk, the protein has been broken up into its component parts. Essentially, it's been predigested, which decreases the likelihood of an allergic reaction.
The infant formulas currently available in the United States are either "iron-fortified"--with approximately 12 milligrams of iron per liter--or "low iron"--with approximately 2 milligrams of iron per liter.
"There should not be a low-iron formula on the market for the average child because a low-iron formula is a nutritionally deficient formula," says Klish. "It doesn't provide enough iron to maintain proper blood cell counts or proper hemoglobin." (Hemoglobin is a blood protein that carries oxygen from the lungs to the tissues, and carbon dioxide from the tissues to the lungs.)
In addition, studies have shown that school children who had good iron status as infants because they were fed iron-fortified formula performed better on standardized developmental tests than children with poor iron status. However, Wallingford says that "FDA has permitted marketing of low-iron formulas because some pediatricians prefer to use them, with the caveat that the physician would be monitoring iron status and prescribing iron supplements when appropriate."
Why is there low-iron formula on the market? "In the past there have been a lot of symptoms that have been attributed to iron, including abdominal discomfort, constipation, diarrhea, colic, and irritability," says Klish. "Also there was some concern about too much iron interfering with the immune system. All of those concerns and questions have been laid to rest with appropriate studies."
Another reason for originally producing low-iron formulas was that human milk contains low amounts of iron--less than a milligram per liter. However, it is now understood that an infant absorbs virtually 100 percent of the iron from human milk, but considerably less from infant formula.
Researchers continue to try to determine the best amount of iron for infant formula. While low-iron formulas don't supply enough iron, the best amount of iron for formulas has not been established. "We did not have much data at the time the regulations were written for different intake levels of iron," says Wallingford. He explains that the current amounts give good developmental results, "but, based on European experience, half [of the high level] is probably good enough to do the same thing." Currently, the Federation of American Societies for Experimental Biology is evaluating what the best levels may be and will make recommendations to FDA on what levels of iron to require in formulas. The study is also reviewing the level of all other nutrients in infant formula, as well as the need for nutrients not currently included.
Both milk and soy formulas are available in powder, liquid concentrate, or ready-to-feed forms. The choice should depend on whatever the parents find convenient and can afford.
Whatever form is chosen, proper preparation and refrigeration are essential. Opened cans of ready-to-feed and liquid concentrate must be refrigerated and used within the time specified on the can. Once the powder is mixed with water, it should also be refrigerated if it is not used right away. The exact amounts of water recommended on the label must be used. Under-diluted formula can cause problems for the infant's organs and digestive system. Over-diluted formula will not provide adequate nutrition, and the baby may fail to thrive and grow.
Until recently, the American Academy of Pediatrics felt that municipal water supplies were safe enough without boiling the water before mixing with the formula. But because of the contamination of Milwaukee's water with the parasite Cryptosporidium in 1993, "the whole business of boiling water has come up again," says Klish. "The academy is now again recommending boiling water for infant formulas."
Klish advises heating the water until it reaches a rolling boil, continue to boil for one to two minutes, and then let it cool. "That should take care of all the bacteria and parasites that might be in the water," he explains.
The American Academy of Pediatrics does not have any recommendations about bottled water. Klish says bottled water is fine, but it still needs to be boiled. "There's no reason to think that bottled water is any safer than city water," he says.
Bottled water must meet specific FDA quality standards for contaminants. These are set in response to requirements that the Environmental Protection Agency has established for tap water.
A new regulation published in the Nov. 13, 1995, Federal Register sets standard definitions for different types of bottled waters, helping resolve possible confusion about what different terms mean.
The regulation also requires accurate labeling of bottled waters marketed for infants. If a product is labeled "sterile," it must be processed to meet FDA's requirements for commercial sterility. Otherwise, the labeling must indicate that it is not sterile and should be used as directed by a physician or according to infant formula preparation instructions.
What about sterilizing the bottles and nipples? "Dishwashers tend to sterilize bottles and nipples fairly well," says Klish. They can also be sterilized by placing in a pan of boiling water for five minutes.
Warming the formula before feeding isn't necessary for proper nutrition, but most infants prefer the formula at least at room temperature. The best way to warm a bottle of formula is by placing the bottle in a pot of water and heating the pot on the stove.
Don't Try This at Home
Homemade formulas should not be used, says Nick Duy, a consumer safety officer in FDA's Office of Special Nutritionals. Homemade formulas based on cows' milk don't meet all of an infant's nutritional needs, and cow's milk protein that has not been cooked or processed is difficult for an infant to digest. In addition, the high protein and electrolyte (salt) content of cow's milk may put a strain on an infant's immature kidneys. Substituting evaporated milk for whole milk may make the homemade formula easier to digest because of the effect of processing on the protein, but the formula is still nutritionally inadequate and still may stress the kidneys.
Today's infant formula is a very controlled, high-tech product that can't be duplicated at home, says Udall.
Isadora B. Stehlin is a member of FDA's public affairs staff.
The milk, however, should be whole milk. Low-fat and skim milk do not have enough fat and calories to supply the nutritional needs of a 1-year-old, explains John Udall, chief of nutrition and gastroenterology at Children's Hospital of New Orleans. At that age, "the child is growing so quickly, and the fat is so important for brain and central nervous system development," he says. "The recommendation that our daily intake of fat should compose less than 30 percent of our caloric intake does not apply to children under 2 years of age."
New on the market are special toddler formulas that claim to be better than milk. The formulas are good nutritionally, says Udall, but they're not necessary. "A well-balanced diet with milk and juices would be just as good in a healthy, normally active, normally growing child," says Udall.
William Klish, chairman of the American Academy of Pediatrics Committee on Nutrition, says that if a child needs to take a vitamin supplement, the toddler formula, fortified with a full range of vitamins and minerals, including iron, can serve that purpose. In addition, the toddler formulas don't need refrigeration, making them a convenient choice for snacks away from home.
The scheme involved the purchase of bulk infant formula labeled "for export only" from a legitimate manufacturer. The bulk formula was then packaged in the 1-pound cans that looked like Similac, an authentic formula made by Ross Products Division of Abbott Laboratories, Columbus, Ohio.
The agency did not receive any reports of illness attributable to the counterfeit formula.
The California counterfeit scheme has been completely suppressed, but it is just part of a diversion market in numerous products. One of FDA's concerns is the conditions the formula is subjected to during the illegal manufacturing operations.
Production records like those normally kept by legitimate manufacturers don't exist, explains Jim Dahl, assistant director of FDA's Office of Criminal Investigations. "How it was transported, what temperature conditions, what sanitary conditions, how cans were treated, how long they were held in those conditions, all of that is unknown," he says.
To protect their babies, parents need to be on the lookout for any changes in formula color, smell or taste, Dahl says. He also advises parents and retailers to: