Nut and peanut butter intake are not directly associated with the risk of endometrial or ovarian cancer: Results from a Dutch prospective cohort study

BACKGROUND & AIMS: Nut intake has been associated with reduced cancer-related mortality and cancer risk. However, very few studies investigated the association between nut consumption and the risk of endometrial and ovarian cancer, with inconclusive results. We prospectively examined the relation between total nut, tree nut, peanut, and peanut butter intake and the risk of endometrial and ovarian cancer in the prospective Netherlands Cohort Study (NLCS).

METHODS: In 1986, 62,573 women aged 55-69 years were included in the NLCS. At baseline, all participants filled in a questionnaire and a subcohort of 2589 women was randomly selected. After 20.3 years of follow-up, 389 endometrial and 347 ovarian cancer cases with complete data were included in the analysis. Hazard ratios (HRs) were calculated in multivariable-adjusted Cox regression analyses, using a case-cohort approach.

RESULTS: Compared to nonconsumers, the HRs (95% confidence intervals) for women consuming 10 + g total nuts/day were 1.23 (0.82-1.87) for endometrial cancer and 0.84 (0.57-1.24) for ovarian cancer. For tree nut, peanut, and peanut butter intake, also no significant relations with endometrial or ovarian cancer were observed. In the endometrial cancer analyses, significant interactions of total nut intake with body mass index and cigarette smoking status were found.

CONCLUSIONS: The results of this study suggest that intake of total nuts, tree nuts, peanuts, and peanut butter is not related to the risk of endometrial or ovarian cancer. The observed interactions in the endometrial cancer analyses, in particular with cigarette smoking status, require confirmation in other studies.