TY - JOUR T1 - CAloric restriction and incidence of breast cancer AU - Michels KB, Ekbom A Y1 - 2004/03/10 N1 - 10.1001/jama.291.10.1226 JO - JAMA SP - 1226 EP - 1230 VL - 291 IS - 10 N2 - Context  Restricting caloric intake is one of the most effective ways to extend lifespan and to reduce spontaneous tumor occurrence in experimental animals, but whether similar associations hold in humans has not been appropriately studied.Objective  To determine whether caloric restriction in early life reduces the risk of invasive breast cancer.Design, Setting, and Participants  Retrospective cohort study using data from the Swedish Inpatient Registry, the Swedish Cancer Registry, the Swedish Death Registry, and the Swedish Fertility Registry. Participants were 7303 Swedish women hospitalized for anorexia nervosa prior to age 40 years between 1965 and 1998. Women were excluded (n = 31) if they were diagnosed with cancer prior to their first discharge from hospitalization for anorexia nervosa.Main Outcome Measure  Incidence of invasive breast cancer.Results  Compared with the Swedish general population, women hospitalized for anorexia nervosa prior to age 40 years had a 53% (95% confidence interval [CI], 3%-81%) lower incidence of breast cancer; nulliparous women with anorexia nervosa had a 23% (95% CI, 79% higher to 75% lower) lower incidence, and parous women with anorexia nervosa had a 76% (95% CI, 13%-97%) lower incidence.Conlusions  Severe caloric restriction in humans may confer protection from invasive breast cancer. Low caloric intake prior to first birth followed by a subsequent pregnancy appears to be associated with an even more pronounced reduction in risk. SN - 0098-7484 M3 - doi: 10.1001/jama.291.10.1226 UR - http://dx.doi.org/10.1001/jama.291.10.1226 ER -