By J. Decker Butzner1,2, MD, FRCPC and Marion Zarkadas2 MSc, RD (Courtesy Celiac News March 2004)
Benefits of Breast-Feeding
Breast milk is the best source of nutrients and many other factors for the growing infant. Its unique composition of proteins, vitamins, minerals, enzymes, hormones, growth factors and anti-infective properties provide the infant with optimal nutrition and protection from infection for the first six months, the time of most rapid growth throughout life. The psychological advantages of breast-feeding for both mother and infant are well recognized. In addition, research indicates that breast-fed infants are less likely to develop obesity, type-I diabetes mellitus, lymphoma, Crohn’s disease and perhaps celiac disease. For mothers who choose not to breast-feed, or in the rare situation where breast-feeding is contraindicated, human infant formula adequately meets the infant’s nutritional requirements.
Only at four to six months do weaning foods need to be introduced, initially in the form of iron supplemented rice cereal. Foods from all food groups are gradually added over the second-half of the first year of life. Most infants adapt to a schedule of three meals a day, sometime between the ages of 10 and 14 months. In addition infants reduce the frequency of breast-feeding over this period, as they become accustomed to increasing amounts of solid foods and other liquids. As the demand for breast milk decreases, the mother’s supply gradually diminishes and weaning from breast milk may be gradually accomplished.
Weaning from breast milk is initiated by substituting a human infant formula for part, and subsequently all, of breast-feeding. Homogenized cow’s milk should not be introduced into the diet until the infant is well established on a wide variety of food groups with an adequate supply of iron, generally around a year of age.
Does breast-feeding protect against celiac disease?
The short answer to this question is that continuing breast-feeding while gluten-containing foods (i.e., foods containing wheat, rye and barley) are being introduced into a child’s diet, protects toddlers and young children from presenting with the classic symptoms of celiac disease. In Sweden there was a recent “epidemic” of celiac disease due to changes in infant feeding practices. They now recommend that gluten containing foods be introduced into the diet in small amounts after five through six months of age, preferably while the child is still given breast milk and not infant formula. It remains to be seen whether this recommendation will reduce the lifetime risk of developing celiac disease, or just delay its development to an older age.
The mechanisms by which breast-feeding protect against celiac disease need to be clarified. The duration of protection is unknown. In spite of these limitations, parents should be encouraged and supported to breast-feed their babies. All experts agree that human milk is the most appropriate food for human infants because it is uniquely adapted to their needs.
In order to reduce the risk of developing celiac disease in early childhood, gluten should be introduced into the infant’s diet gradually in small? amounts at age five to six months, while breast-feeding is continued. Breast-feeding for at least one month after the introduction of gluten may further reduce the risk of developing celiac disease in early childhood. It is not known if this will reduce lifetime risk or just delay the age of developing celiac disease. Additional genetic and environmental factors likely play a role in the development of celiac disease.
Unfortunately the Swedish study did not define what a “small” amount was.
Research supporting this recommendation
Here are the data to support the recommendation about the protective effect of breast-feeding on celiac disease. In Sweden, between 1973 and 1984, the annual incidence rate of symptomatic celiac disease in children under the age of two years remained quite stable at about 65 cases per 100,000 person years. In 1985, a dramatic increase in cases was observed. The incidence rate in children below two years of age increased by four times to 200-240 cases per 100,000 years from 1987-1994. After 1995, the incidence returned to the historical level of 50-60 cases per 100,000 person years.
To understand what caused the epidemic, a group of Swedish researchers collected national data on length of breast-feeding, gluten intake of children at weaning, and medical recommendations on how to wean babies. They examined trends throughout the 18-year period that bracketed the epidemic. Their analysis demonstrated that waiting until a child was at least six months of age before introducing gluten into the diet, reduced the risk of developing celiac disease by approximately 25% when compared with introducing gluten-containing cereals at an earlier age. They also found that the percentage of Swedish women who were breast-feeding their infants at six months of age, increased over the time of the study from a low of 37% in 1980 to a high of 76% in 1997. They found that a mother, who regularly breast-fed while she introduced gluten-containing foods, reduced the chance that a child would develop celiac disease by 40% as compared to a child who had previously been weaned from the breast.
When a woman continued breast-feeding for greater than one month beyond her infant’s introduction to gluten-containing foods, the risk of the child developing celiac disease fell by 65%, compared to children that had been previously weaned. They also found that the epidemic was related to the introduction of a specialized wheat-fortified infant weaning formula. As a result of these findings, the age of introduction of this product in Sweden has been delayed, and gluten is now being introduced in smaller amounts.
These researchers concluded that the epidemic was due, at least in part, to a change in at least three factors associated with infant feeding, namely: the amount of gluten given; the age at introduction of gluten; and whether breast-feeding was ongoing or not when gluten was introduced. By altering these factors, the annual incidence of celiac disease decreased to pre-epidemic levels. It remains to be determined if these alterations will provide a lifetime of protection against the development of celiac disease or just postpone its development to an older age.
The reason for caution in stating that breast-feeding will prevent celiac disease comes from multiple epidemiological studies from Scotland, Great Britain and Finland, which demonstrated a dramatic fall in the incidence of symptomatic disease in children in the mid-1970’s. Subsequently, these dramatic declines have been associated with an upward shift in age of diagnosis in children and adolescents, who present mostly with extraintestinal complaints.
These studies hypothesize that the dramatic falls observed were in some part due to changes in infant feeding practices but this was not closely examined. What was noted in each study was that the cumulative incidence of celiac disease, that is the total number of cases observed by about 18 years of age, did not differ over time. Only the age of presentation did. Interestingly, recent data from Sweden suggests that during the epidemic, the median age of diagnosis was unchanged while the decline in incidence noted at the end of the epidemic, was accompanied by an increase in the median age of diagnosis from 1.1 to 3.7 years. These older Swedish children however, did not receive the currently recommended feeding protocol. Further data are needed to determine if this trend will continue.
In addition, there have been three “case control” studies which suggest that exclusive breast-feeding compared to formula or mixed feeding, either reduces the risk of celiac disease or delays the onset of symptoms in young children. A case control study is a study where a child who develops celiac disease is compared with an age and sex matched control that does not develop the disease. Case control studies rely on people remembering details about past behaviours and recall bias is common. In these studies, the question asked was “how the child was fed in early infancy”. Each study demonstrated that the risk of celiac disease was highest in those infants breast-fed for the shortest period. Once again, these investigators could not comment on whether prolonged breast-feeding would continue to have a protective effect in adolescence and adulthood or just delay the development of celiac disease.
Ivarsson, A. et al. Epidemic of coeliac disease in Swedish children. ACTA Paediatr 2000:89:165-71.
Ivarsson, A. et al. Breast-feeding protects against celiac disease. Am J Clin Nutr 2002:75:914-21.
Nash, S. Does exclusive breast-feeding reduce the risk of celiac disease in children? Br J Community Nurs. 2003:8:127-32.
Troncone, R. et al. The controversial epidemiology of coeliac disease. ACTA Paediatr 2000:89:140-141.
Division of Gastroenterology and Nutrition, Department of Pediatrics, Alberta Children’s Hospital and the University of Calgary, Calgary, Alberta
Member of the Professional Advisory Board of the Canadian Celiac Association