Design a preliminary research proposal to study the relationship Essay

Design a preliminary research proposal to study the relationship between breast cancer and fruit & vegetable consumption - Essay Example In the last decade there were determined following risk factors for breast cancer occurrence: family history of breast cancer, early menarche, personal history of breast cancer and previous abnormal breast biopsy, late menopause, race, age, the continuous use of the hormonal preparations, null parity, refuse of breast feeding, obesity etc. Nevertheless the role of dietary factors in breast cancer epidemiology is still unclear. The recent national survey conducted in the United Kingdom was designed as a cohort study assessing the diet of British citizens. This survey (Cancer Research UK EPIC-Oxford study) was aimed to determine the impact of dietary factors on the hormone production and relative risk of breast cancer (van Gils et al., 2005). The primary statistical analysis showed the presence of correlation between the blood levels of estrogens and intake of phytoestrogenes, food fibres, saturated and trans fatty acids, refined sugars etc. Contrarily, there were determined characteristics of the diet having preventive impact on the breast health. Thus low-protein diet and diet restricted in fat and sugars was correlated with lower breast cancer risk. Some investigators discussed the role of fruits and vegetables in the prevention of breast cancer (Freudenheim et al., 1996, Gandini et al., 2000; Smith-Warner S., 2001; Adzersen et al., 2003). The WCRF/AICR guideline (1997) includes recommendations to decrea se the quantities of animal food (red meat, fat) and alcohol and to enrich diet with fruits and vegetables (see table 1 in the Appendix). Some researchers found that both vegetables and fruits intake can decrease breast cancer risk. For example Freudenheim et al. (1996) suggested that the intake of vegetables decreases a risk of premenopausal breast cancer. The authors explain protective impact of the vegetables by the high content of the antioxidant agents (e.g.beta-carotene, lutein and zeaxanthin) in green vegetables. Similar data were obtained in the meta-analysis performed by the group of Italian researchers (Gandini et al., 2000). They confirmed the existence of the association between lower breast cancer risk and the intake of vegetables and fruits. On the other hand van Gils et al. (2005) stated in their prospective study that there were "observed no association of risk with either total consumption of vegetables and fruits or with vegetable subgroups" (p. 191). Accordingly to this statement there was developed a deduction about the absence of any significant protective effects for vegetable or fruit intake in relation to breast cancer risk. But the hypothesis about the possibility of such effects is still applicable for the observation of specific subgroups of females. Yorkshire Breast Cancer Research Group reported about the significant declining mortality from breast cancer in this England's largest county (Pisani & Forman, 2004). Authors did not discuss the role of diet in this declining, but they considered that it was rather a result of the long-term effects of both mammography screening and increased use of systemic therapy (p. 152). Yorkshire community took part in the EPIC-Oxford study; nevertheless there were not assessed issues of traditional Yorkshire meal characterising with prevalence of starchy and fatty food (e.g. Yorkshire pudding, Yorkshire parkin, fat rascals etc). Thus regional