Dietary fiber intake and ovarian cancer risk: a prospective cohort study

Abstract

There is some evidence from case-control studies that dietary fiber intake might be inversely associated with ovarian cancer risk, but there are limited prospective data. Therefore, we examined ovarian cancer risk in association with intake of dietary fiber in a prospective cohort of 49,613 Canadian women enrolled in the National Breast Screening Study (NBSS), who completed a self-administered food frequency questionnaire between 1980 and 1985. Linkages to national mortality and cancer databases yielded data on deaths and cancer incidence, with follow-up ending between 1998 and 2000. Data from the food frequency questionnaire were used to estimate intake of total dietary fiber, of fiber fractions, and of fiber from various sources. Cox proportional hazards models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI) for the association between energy-adjusted quartile levels of fiber intake and ovarian cancer risk. During a mean 16.4 years of follow-up, we observed 264 incident ovarian cancer cases. Total dietary fiber and fiber fractions were not associated with ovarian cancer risk in this study population.

Dietary Intake and Ovarian Cancer Risk: A Systematic Review

“…Finally, our results suggest that tea intake may be associated with lower risk of ovarian cancer (43), although not consistently (37), while coffee and caffeine showed no association. A meta-analysis that included 1244 cases of epithelial ovarian cancer did not support a lower risk with either coffee or tea intake (47).…”

“…Of note, nitrites from plant sources were not associated with risk. Fiber intake was evaluated as a possible protective dietary exposure in one study in Canada and while point estimates were below 1.0, neither total fiber nor specific types of fiber showed a significantly lower risk for ovarian cancer (43). Sugar intake including total sugar, total fructose and total sucrose were associated with a lower risk of ovarian cancer in the AARP cohort (44), but higher risk in a study that included 264 epithelial ovarian cancer cases in Canada (45).…”

Dietary carbohydrate intake, glycaemic load, glycaemic index and ovarian cancer risk in African-American women

“…The evidence regarding the association between fibre intake and ovarian cancer risk has been inconsistent. Although some studies found no association between fibre intake and the risk of ovarian cancer (10,14,21,44) , others found an inverse association (9,(11)(12)(13)20) . Two of these studies further examined types of fibre intake and showed that the inverse association was observed only for vegetable fibre but not for fruit or cereal fibre (11,20) .…”

“…Carbohydrates in particular have been a focus of research (6) , as long-term consumption of high levels of carbohydrates, especially sugars, could plausibly contribute to ovarian carcinogenesis (7,8) . The majority of epidemiological studies evaluating associations between intakes of carbohydrate (9)(10)(11)(12)(13)(14)(15) , total sugars and added sugars (13,(15)(16)(17)(18)(19) and fibre (9)(10)(11)(12)(13)(14)20,21) and ovarian cancer risk have been conducted in European or European-American populations with mixed results. Inconsistencies in findings have been attributed to the different type, amount and rate of digestion of carbohydrates (13) .…”

Pre-diagnosis diet and survival after a diagnosis of ovarian cancer

“…To date, no other studies have explored this association. Findings for the association between fibre intake and ovarian cancer risk have been mixed (Silvera et al , 2007a; Hedelin et al , 2011), although fibre intake has been associated with lower breast cancer mortality (Belle et al , 2011; Buck et al , 2011). A high-fibre, low-fat dietary intervention was shown to reduce bioavailable oestrogen among women diagnosed with breast cancer, a plausible mechanism in the context of improving ovarian cancer survival (Rock et al , 2004).…”