Breast feeding and acute appendicitis

BMJ 1995; 310 doi: (Published 01 April 1995) Cite this as: BMJ 1995;310:836
  1. Alfredo Pisacane, senior lecturera,
  2. Ugo de Luca, senior registrarb,
  3. Nicola Impagliazzo, postgraduate traineea,
  4. Maria Russo, postgraduate traineea,
  5. Carmela De Caprio, postgraduate traineeb,
  6. Giuseppe Caracciolo, professorb
  1. a Dipartimento di Pediatria, Universita di Napoli, 80131 Naples, Italy
  2. b Divisione di Chirurgia, Ospedale Santobono, USL 40 Regione Campania, Italy
  1. Correspondence to: Dr Pisacane.
  • Accepted 18 January 1995

Acute appendicitis is the commonest reason for abdominal surgery in many countries, but its cause is unknown.1 The hygiene hypothesis attributes the rise in appendicitis that occurred in the United Kingdom at the beginning of this century to improvements in sewage disposal and water supplies in the late 19th century.2 These improvements in hygiene greatly reduced the exposure of infants to enteric organisms that programme the immune system of the gut, thereby rendering the bowel more susceptible to triggering infection later in life. Knowledge about risk factors for appendicitis is, however, poor, and the roles of diet,3 housing, and amenities such as hot water and bathroom facilities are doubtful.4 Because breast feeding can modify the exposure or the type of immune response to some microbial agents during infancy, we investigated the relation between infant feeding and acute appendicitis in a case incident, population based case-control study.

Patients, methods, and results

All 222 children admitted to Santobono Paediatric Hospital, Naples, between 1 January and 30 November 1993 with histologically confirmed acute appendicitis were recruited for the study. All these children were living in the Naples area. Their mothers were interviewed during the stay in hospital by two nurses unaware of the objectives of the study. Controls were 222 children randomly selected from around 3000 attending 10 randomly selected primary schools in the Naples area that had been enrolled in a child health survey. All the mothers sampled agreed to be interviewed at home by the same two nurses during 1993.

Relative risk was calculated by odds ratios with confidence intervals by Cornfield's method. Confounding and effect modification were investigated by stratified analysis. The table shows the characteristics of the groups.

The mean duration of breast feeding was 96.9 days (SD 115.6) for cases and 130.2 days (134.8) for controls (Mann-Whitney U test; two-tailed P value 0.001). Stratified analysis showed that no factor among those we analysed (birth weight, sex, type of delivery, maternal education, and number of other children in the household) confounded or modified the association between feeding and illness.


Our data indicate that children with acute appendicitis were less likely than controls to have been breast fed for a prolonged length of time.

There are several reasons why prolonged breast feeding may be associated with a decreased risk of acute appendicitis. The immune components of human milk provide an antigen avoidance system that can decrease the severity of infection and probably the inflammatory reactions associated with it.5 This milder inflammatory response could programme the immune system of the infant, its effects lasting for several years, and it could be associated with a more tolerant lymphoid tissue at the base of the appendix. Alternatively, prolonged breast feeding may be a marker of some unknown socioeconomic characteristic that could be associated with a low risk of illness.

Acute appendicitis may represent another case in which the infant environment is an important determinant of adult disease, even if our data generate rather than test a hypothesis and need to be confirmed by further research.

Characteristics of cases and controls. Values are numbers of subjects unless stated otherwise

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