1755P - Carbohydrate quality index and incidence of obesity-related cancers: The Seguimiento Universidad de Navarra (SUN) project

Background

Obesity is a strong risk factor for cancer, with more than 40,000 diagnosed cancers every year attributed to obesity. The role of nutrition in obesity-related cancers (ORC) needs to be better understood to develop tailored prevention strategies. The quality, rather than the quantity, of carbohydrate intake, seems to play a significant role. We investigated the relationship between dietary carbohydrate quality and risk of developing ORC in the "Seguimiento Universidad de Navarra” (SUN) Mediterranean cohort.

Methods

A total of 18,446 Spanish university graduates [mean age 38 years (SD 12), 61% women, mean BMI 23.5 kg/m2 (SD 3.5 kg/m2)], with no personal history of cancer, were followed-up for a median of 13.7 years. Baseline carbohydrate quality index (CQI) was assessed using 4 previously defined criteria: high dietary fibre intake, low glycemic index, high whole-grain: total-grain ratio and high solid carbohydrate: total carbohydrate ratio. Subjects were classified into tertiles according to their CQI score. Obesity-related incident cases were confirmed by an oncologist using medical records and by querying the National Death Index blindly to dietary exposures.

Results

During follow-up, 269 incident cases of obesity-related cancer were confirmed. A higher quality of carbohydrate intake, as measured by the baseline CQI, was associated with a lower risk of ORC with multivariable-adjusted hazard ratio (HR) for the upper (T3) versus the lowest tertile (T1) of 0.68 (95% confidence interval: 0.48, 0.97). Particularly, a higher dietary fibre intake was inversely associated with ORC, HR T3 vs. T1 = 0.58 (0.38, 0.89).

Conclusions

In this Mediterranean cohort, we observed a significant inverse association between a better global quality of carbohydrate intake and the risk of obesity-related cancers. This finding suggests that strategies for cancer prevention should emphasize the quality of carbohydrate intake, and particularly the dietary fibre intake.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

University of Navarra.

Funding

Spanish Government-Instituto de Salud Carlos III, and the European Regional Development Fund (FEDER) (RD 06/0045, CIBER-OBN, Grants PI10/02658, PI10/02293, PI13/00615, PI14/01668, PI14/01798, PI14/01764, PI17/01795, PI20/00564 and G03/140), the Navarra Regional Government (27/2011, 45/2011, 122/2014), and the University of Navarra.

Disclosure

All authors have declared no conflicts of interest.