Dietary fatty acids and endometrial cancer risk within the European Prospective Investigation into Cancer and Nutrition

Abstract

Background: Diet may impact important risk factors for endometrial cancer such as obesity and inflammation. However, evidence on the role of specific dietary factors is limited. We investigated associations between dietary fatty acids and endometrial cancer risk in the European Prospective Investigation into Cancer and Nutrition (EPIC).

Methods: This analysis includes 1,886 incident endometrial cancer cases and 297,432 non-cases. All participants were followed up for a mean of 8.8 years. Multivariable Cox proportional hazard models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI) of endometrial cancer across quintiles of individual fatty acids estimated from various food sources quantified through food frequency questionnaires in the entire EPIC cohort. The false discovery rate (q-values) was computed to control for multiple comparisons.

Results: Consumption of n-6 γ-linolenic acid was inversely associated with endometrial cancer risk (HR comparing 5th with 1st quintile_Q5-Q1=0.77, 95% CI = 0.64; 0.92, p_trend=0.01, q-value = 0.15). This association was mainly driven by γ-linolenic acid derived from plant sources (HR_{per unit increment}=0.94, 95%CI= (0.90;0.98), p = 0.01) but not from animal sources (HR_{per unit increment}= 1.00, 95%CI = (0.92; 1.07), p = 0.92). In addition, an inverse association was found between consumption of n-3 α-linolenic acid from vegetable sources and endometrial cancer risk (HR_{per unit increment}= 0.93, 95%CI = (0.87; 0.99), p = 0.04). No significant association was found between any other fatty acids (individual or grouped) and endometrial cancer risk.

Conclusion: Our results suggest that higher consumption of γ-linolenic acid and α-linoleic acid from plant sources may be associated with lower risk of endometrial cancer.

Keywords: Diet; Endometrial cancer; Epidemiology; Fatty acids.

Fig. 1

Associations between plant and animal sources of gamma- and alpha-linolenic acids with endometrial cancer risk gamma-linolenic acid (18:3n-6): The percentage of contribution next to the food sources was calculated for each food (sub-) group based on the mean daily intake reported in the dietary questionnaire. It represents the contribution of the corresponding source to the gamma-linolenic acid intake. Contribution of the plant sources (potatoes and other tubes (0.5%), vegetables (2%), fruit, nuts and seeds (0.2%), cereal and cereal products (14%), fat (19.7%), condiments and sauces (27.6%), soups and bouillons (0.3%) and miscellaneous (0.7%)) to γ-linolenic acid = 65.0% vs. animal sources (dairy products (6.6%), meat and meat products (13.7%), fish and shellfish (2.8%) and egg and egg products (7.8%)) = 30.9% alpha-linolenic acid (18:3n-3): The percentage of contribution next to the food sources was calculated for each food (sub-) group based on the mean daily intake reported in the dietary questionnaire. It represents the contribution of the corresponding source to the alpha-linolenic acid intake. Contribution of the plant sources (potatoes and other tubes (0.3%), vegetables (0.3%),legumes (1.7%), cereal and cereal products (27.9%), fat (33.4%), sugar and confectionery (0.7%) non-alcoholic beverages (0.1%), condiments and sauces (22.4%) and soups and bouillons (0.3%)) to α-linolenic acid = 87.1% vs. animal sources (dairy products (3.8%), meat and meat products (3.5%), fish and shellfish (0.7%), egg and egg products (0.4%) and butter (2.3%)) = 10.7% HR = Hazard Ratio; CI = confidence interval. The multivariable model was adjusted for BMI (continuous), number of full-term pregnancies (number of live born and/or still born children; 0, 1–2, 3–4; >4; missing), smoking status (never, former, current), oral contraceptive or HRT use (never or ever), menopausal status at enrolment (premenopausal; postmenopausal; perimenopausal/unknown menopause), age at menarche (continuous) and total energy intake (continuous)