Cut fat young to reduce breast cancer risk
already an obession among many western girls, could help lower the
risk of breast cancer later on.
Reducing fat intake during puberty could help lower the risk of breast cancer later on, report researchers in today's Journal of the National Cancer Institute.
The researchers from the Fox Chase Cancer Center in Philadelphia, US, found that a small reduction in dietary fat in adolescents was associated with changes in the levels of certain sex hormones. It is elevated levels of these sex hormones which have been linked with an increase in breast cancer risk among adults.
Dr Joanne F. Dorgan and her colleagues conducted a study alongside the Dietary Intervention Study in Children to examine whether diet influences sex hormone levels during adolescence. The study involved 286 girls aged 8 to 10 who were randomly assigned to a low-fat dietary intervention group or to a group receiving usual care (eg educational materials available to the public). The researchers measured blood sex hormone levels at the start of the study and one, three, five, and seven years later.
After five years, girls in the intervention group had 29.8 per cent lower oestradiol, 30.2 per cent lower non-sex hormone binding globulin-bound oestradiol, 20.7 per cent lower estrone, and 28.7 per cent lower estrone sulphate levels during the first half of their menstrual cycles and 27.2 per cent higher testosterone levels during the second half of their menstrual cycles compared with girls in the usual care group.
After seven years, girls in the intervention group had half the progesterone levels during the second half of their menstrual cycles as did girls in the usual care group.
Girls in the intervention group reported consuming less total and saturated fat overall than girls in the usual care group. Girls in the intervention group also reported consuming more dietary fibre.
Although their study found that a low-fat diet resulted in reductions in oestrogen hormone concentrations, the authors say that "whether these differences ultimately influence breast cancer risk is unknown." A parallel study was conducted in boys, and results will be reported separately.
