Environment and Breast Cancer: Science Review
About
Premenopausal dietary carbohydrate, glycemic index, glycemic load, and fiber in relation to risk of breast cancer
Cho, E., Spiegelman, D., Hunter, D. J., Chen, W. Y., Colditz, G. A., Willett, W. C. Cancer Epidemiol Biomarkers Prev. 2003. 12:11 Pt 1, 1153-8.
Topic area
Diet - Body size
Diet - Body size
Study design
Prospective cohort
Prospective cohort
Funding agency
NCI, NIH, and Breast Cancer Research Foundation
NCI, NIH, and Breast Cancer Research Foundation
Study Participants
Number of Cases
714
714
Menopausal Status
The menopausal status of women included in this study is listed here.
Pre menopausal
Number in Cohort
Cohort: 90,655
Cohort: 90,655
Cohort participation rate
Retention/participation exceeded 70% for exposed a
Retention/participation exceeded 70% for exposed a
Participant selection: Inclusion and exclusion criteria
Criteria used to select participants in the study.
In: Female registered nurses participating in the Nurses' Health Study II, who were 25-42 years of age when they responded to the 1989 questionnaire. Cases were invasive only.
Ex: Women who had: implausible total energy intake, left more than 70 food items blank in the 1991 FFQ, reported a diagnosis of cancer, except non-melanoma skin cancer before returning the 1991 questionnaire, reported post-menopausal status
Comment about participation selection
Strengths: Large cohort, analyzed young women; cases were confirmed with hospital records, self reports were 98% accurate; analyzed breast cancer risk according to quintiles of cumulative averaged dietary carbohydrate, glycemic index and glycemic load by BMI; the prospective nature of the study avoided possible recall bias; few participants were lost to follow-up; repeated measures of dietary intake enabled the examination of long-term averaged diet as well as baseline intake; wide range of information on potential confounders allowed for the appropriate adjustments in analysis, menopausal status assess at baseline Limitations: short duration of follow-up; cases were limited; does not discuss how they obtained anthropometric data
Strengths: Large cohort, analyzed young women; cases were confirmed with hospital records, self reports were 98% accurate; analyzed breast cancer risk according to quintiles of cumulative averaged dietary carbohydrate, glycemic index and glycemic load by BMI; the prospective nature of the study avoided possible recall bias; few participants were lost to follow-up; repeated measures of dietary intake enabled the examination of long-term averaged diet as well as baseline intake; wide range of information on potential confounders allowed for the appropriate adjustments in analysis, menopausal status assess at baseline Limitations: short duration of follow-up; cases were limited; does not discuss how they obtained anthropometric data
Exposures investigated
Carbohydrates, glycemic load (GL), glycemic index (GI), BMI
Carbohydrates, glycemic load (GL), glycemic index (GI), BMI
How exposure was measured
Questionnaire, self-administered, FFQ
Questionnaire, self-administered, FFQ
Statistical Analysis
Breast cancer outcome investigated
Primary breast cancer
Primary breast cancer
Ethnic groups with separate analysis
If this study provided a separate analysis by ethnic or racial group, the groups are listed here.
No
Confounders considered
Other breast cancer risk factors, such as family history, age at first birth, and hormone replacement therapy use, that were taken into account in the study.
Not considered: Race
Genetic characterization included
If the study analyzed relationships between environmental factors and inherited genetic variations, this field will be marked “Yes.” “No”, if not.
No
Description of major analysis
Adjusted RR with 95% CI; higher versus lower quintile of intake; stratified jointly for age and calendar year of the questionnaire, cross-product term of carbohydrate intake and BMI, subgroup for premenopausal women at diagnosis; follow-up 8 years
Adjusted RR with 95% CI; higher versus lower quintile of intake; stratified jointly for age and calendar year of the questionnaire, cross-product term of carbohydrate intake and BMI, subgroup for premenopausal women at diagnosis; follow-up 8 years
Strength of associations reported
Carbohydrates: 0.89 (0.63-1.26); GI: 1.05 (0.83-1.33); GL: 1.06 (0.78-1.45).
Association between premenopausal breast cancer risk and women who have a high average dietary carbohydrate consumption, 59.4% of total energy/day vs. 41.2%, with a BMI of less than 25, OR=0.62(0.40-0.97) trend p=0.02
Association between premenopausal breast cancer risk and women who have a high average dietary carbohydrate consumption, 59.4% of total energy/day vs. 41.2%, with a BMI of 25 or greater, OR=1.47(0.84-2.59) trend p=0.14
Association between premenopausal breast cancer risk and women who have a high average glycemic index, 82 vs. 70, with a BMI of 25 or greater, OR=1.05(0.72-1.52) trend p=0.98
Association between premenopausal breast cancer risk and women who have a high average glycemic load, 211 vs. 138, with a BMI of 25 or greater, OR=1.46(0.89-2.39) trend p=0.14
Carbohydrates: 0.89 (0.63-1.26); GI: 1.05 (0.83-1.33); GL: 1.06 (0.78-1.45).
Association between premenopausal breast cancer risk and women who have a high average dietary carbohydrate consumption, 59.4% of total energy/day vs. 41.2%, with a BMI of less than 25, OR=0.62(0.40-0.97) trend p=0.02
Association between premenopausal breast cancer risk and women who have a high average dietary carbohydrate consumption, 59.4% of total energy/day vs. 41.2%, with a BMI of 25 or greater, OR=1.47(0.84-2.59) trend p=0.14
Association between premenopausal breast cancer risk and women who have a high average glycemic index, 82 vs. 70, with a BMI of 25 or greater, OR=1.05(0.72-1.52) trend p=0.98
Association between premenopausal breast cancer risk and women who have a high average glycemic load, 211 vs. 138, with a BMI of 25 or greater, OR=1.46(0.89-2.39) trend p=0.14
Results Comments
Premenopausal dietary carbohydrate, glycemic index, glycemic load were not strongly related to overall breast cancer risk. However the associations with carbohydrate intake and glycemic load differed by body weight.
Premenopausal dietary carbohydrate, glycemic index, glycemic load were not strongly related to overall breast cancer risk. However the associations with carbohydrate intake and glycemic load differed by body weight.
Author address
Department of Medicine, Harvard Medical School and Brigham and Women's Hospital, Boston, Massachusetts 02115, USA. eunyoung.cho@channing.harvard.edu
Department of Medicine, Harvard Medical School and Brigham and Women's Hospital, Boston, Massachusetts 02115, USA. eunyoung.cho@channing.harvard.edu