Several animal studies have found that reducing caloric intake by one-third to one-half for the animals' lifetime prevents various types of cancer, but the implications of short-term caloric restriction are largely unknown. However, reproducing these types of studies in humans raises ethical and practical issues.
During World War II, a famine in the western part of The Netherlands resulted from a food embargo imposed by German authorities. Between 1983 and 1986, about 15,000 women participating in a Dutch breast cancer screening program who were between ages 2 and 33 during the 19441945 famine responded to a questionnaire about their famine experience. Sjoerd G. Elias, Ph.D., of the Julius Center for Health Sciences and Primary Care at the University Medical Center Utrecht, The Netherlands, and colleagues used data gathered from these women to study the effects of the famine on subsequent breast cancer risk.
Women were given a famine exposure score--absent, moderate, or severe exposure to famine--based on information about hunger, cold, and weight loss. The risk of breast cancer increased with increasing severity of famine exposure. For example, women who experienced severe exposure to famine had a 48% increased risk of breast cancer compared with women who were not affected by the famine. The association between famine exposure and breast cancer risk was highest among women who were between ages 2 and 9 during the famine compared with women exposed at older ages. The risk was also stronger among women who never gave birth compared with women who had children.