Diet, menopause, and risk of hormone-related cancers

Background: The timing of menopause can predict the duration of vasomotor menopausal symptoms (VMS), as well as the risk of hormone-related cancers such as ovarian, endometrial and breast cancer. Although evidence suggest an association between diet and the timing of menopause and its associated sequelae, current evidence are limited and conflicting. Thus, this thesis studied the associations between diet and age at natural menopause, the presence of VMS and the risk of hormone-related cancers. Methods: Two of the largest and most complete datasets in the world were used to explore this topic: the UK Women's Cohort Study (UKWCS) and the International collaboration for a Life course Approach to reproductive health and Chronic disease Events (InterLACE). Results: In the UKWCS, prospective analyses demonstrated that high intakes of oily fish and fresh legumes were associated with a delayed onset of menopause. Conversely, refined pasta and rice was associated with an earlier menopause. Specific dietary patterns were also linked to the onset of natural menopause. Furthermore, survival analyses demonstrated that intakes of processed meat and total meat were associated with a higher risk of breast and endometrial cancer. Higher intakes of tomatoes and dried fruits were inversely associated with breast and endometrial cancer respectively. Using InterLACE consortium, a pooled analysis of three studies showed that soy product consumption was protective against the incidence of VMS. Conclusion: This work has demonstrated, for the first time, how diet can play a role in influencing age at natural menopause in the UK. Further evidence for an association between diet and the presence of VMS and the risk of hormone-related cancers was provided. The complexity and cultural variations in diet suggest the need for further observational studies as well as randomized control trials to confirm whether specific dietary changes could modify the timing of natural menopause.