Environment and Breast Cancer: Science Review

Vitamins C and E, retinol, beta-carotene and dietary fibre in relation to breast cancer risk: a prospective cohort study
Verhoeven, D. T., Assen, N., Goldbohm, R. A., Dorant, E., van 't Veer, P., Sturmans, F., Hermus, R. J., van den Brandt, P. A. Br J Cancer. 1997. 75:1, 149-55.

Topic area
Diet
Diet
Study design
Prospective case-cohort
Prospective case-cohort
Funding agency
Other: Dutch Cancer Society
Other: Dutch Cancer Society

Study Participants
Number of Cases
659
659
Menopausal Status
The menopausal status of women included in this study is listed here.
Post menopausal
Number in Cohort
Sub-cohort: 1716/ cohort: 62,573
Sub-cohort: 1716/ cohort: 62,573
Country where study was conducted
Netherlands
Netherlands
Cohort participation rate
Not mentioned
Not mentioned
Participant selection: Inclusion and exclusion criteria
Criteria used to select participants in the study.
In: Women aged 55-69 participating in the Netherlands Cohort Study
Ex::History of cancer at baseline other than non-melanoma skin cancer; cases in which the cancer was not microscopically confirmed; cases with in situ carcinoma of the breast; subjects with incomplete or inconsistent dietary data
Comment about participation selection
Large cohort
Large cohort
Exposures investigated
Vitamins C and E, beta-carotene, fruits, vegetables
Vitamins C and E, beta-carotene, fruits, vegetables
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: BMI
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: highest versus lowest quintile of intake, subgroup for vitamin C supplement, stratified by intake of PUFA (polyunsaturated fatty acid), follow up 4.3 years
Adjusted RR with 95%CI: highest versus lowest quintile of intake, subgroup for vitamin C supplement, stratified by intake of PUFA (polyunsaturated fatty acid), follow up 4.3 years
Strength of associations reported
β carotene: 1.01 (0.72-1.42); vitamin C: 0.77(0.55-1.08); vitamin E: 1.25(0.85-1.85); fruits: 0.76 (0.54-1.08); vegetables: 0.94 (0.67-1.31)
β carotene: 1.01 (0.72-1.42); vitamin C: 0.77(0.55-1.08); vitamin E: 1.25(0.85-1.85); fruits: 0.76 (0.54-1.08); vegetables: 0.94 (0.67-1.31)
Results Comments
No evidence that a high intake of fruits, vegetables, beta-carotene or vitamin E decrease the risk of breast cancer. Vitamin C had a moderate non-significant decline of risk with increasing intake.
No evidence that a high intake of fruits, vegetables, beta-carotene or vitamin E decrease the risk of breast cancer. Vitamin C had a moderate non-significant decline of risk with increasing intake.

Author address
TNO Nutrition and Food Research Institute, Zeist, The Netherlands.
TNO Nutrition and Food Research Institute, Zeist, The Netherlands.