Dietary Carbohydrate, Glycemic Index, Glycemic Load, and Breast Cancer Risk Among Mexican Women.
BACKGROUND
Very few studies have focused on the relationship among dietary carbohydrates, glycemic index (GI), glycemic load (GL), and breast cancer risk in Latin American women. Our objective was to assess the associations among dietary carbohydrate, GI, GL, and risk of breast cancer, and to further investigate these associations by levels of overweight/obesity and physical activity.


METHODS
We used data from a Mexican population-based case-control study. We recruited a 1,000 women with incident breast cancer and 1,074 matched control women ages 35 to 69 years between 2004 and 2007. We used conditional logistic regression models and energy-adjusted carbohydrates, GI, and GL using the residual method.


RESULTS
Total carbohydrate intake was associated with an increased risk of breast cancer among premenopausal women. The odds ratio in the highest versus the lowest quartile was 1.3 (95% confidence interval = 1.0, 1.7; P trend = 0.03). In stratified analyses by body mass index (BMI), the positive association between carbohydrate and risk of premenopausal breast cancer was only observed among overweight women. The odds ratio comparing the top with the bottom quartile was 1.9 (95% confidence interval = 1.2, 3.0; P trend = 0.01) among women with BMI ≥ 25 kg/m. No association was observed among women with BMI < 25 kg/m.


CONCLUSIONS
Our findings suggest that high carbohydrate diets are associated with an increased risk of breast cancer among premenopausal Mexican women.
From the aNutrition and Metabolism Section, International Agency for Research on Cancer, Lyon, France; bPierre Hainaut, University of Strathclyde School of Global Public Health @ International Prevention Research Institute, Lyon, France, cInstitut Albert Bonniot/INSERM 823, Grenoble, France; dInstituto Nacional de Salud Pública, Cuernavaca, Morelos, Mexico; and eAutonomous Metropolitan University, Iztapalapa Mexico City, Mexico.
Amina
A
Amadou
Julie
J
Degoul
Pierre
P
Hainaut
Veronique
V
Chajes
Carine
C
Biessy
Gabriela
G
Torres Mejia
Inge
I
Huybrechts
Hortensia
H
Moreno Macia
Caro
C
Ortega
Anjélica
A
Angeles-Llerenas
Isabelle
I
Romieu
D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000453:epidemiology*; D016022:Case-Control Studies; D004032:Diet / Q000706:statistics & numerical data*; D004040:Dietary Carbohydrates; D005260:Female; D038321:Glycemic Index; D000067940:Glycemic Load; D006801:Humans; D016015:Logistic Models; D008800:Mexico / Q000453:epidemiology; D008875:Middle Aged; D009043:Motor Activity; D009765:Obesity / Q000453:epidemiology*; D016017:Odds Ratio; D050177:Overweight / Q000453:epidemiology
D004040:Dietary Carbohydrates