Female university students best fit the profile for high risk of developing breast cancer, a Spanish study has found.
Nicolas Olea examined the data on 500 women admitted to the Hospital Clinico, in Grenada, Spain, between 1996 and 1998 for cancer-related surgery.
He has concluded that the risks of developing breast cancer were linked to reproductive habits - and young female university students fit all the criteria that Dr Olea describes as making women more prone to the disease, such as the use of cosmetics and "the abuse of alcohol and tobacco".
Dr Olea added that female students do not generally adhere to guidelines for breast cancer prevention, which include having a first child before the age of 19, giving birth to more than four children and accumulating more than 36 months of breast-feeding.
The risk of breast cancer is four times higher among women who do not fit the preventative profile.
During pregnancy and lactation women's oestrogen levels decrease. In high concentrations, this hormone - necessary for normal reproductive functioning - is linked to breast cancer.
Female university students were exposed to excessive amounts of oestrogen in the environment, Dr Olea suggested. Oestrogen or oestrogen-mimicking substances, such as parabens and ftalos, can be found in some cosmetics and ultraviolet filters.