Fruit and vegetable consumption in adolescence and early adulthood and risk of breast cancer: population based cohort studyBMJ 2016; 353 doi: https://doi.org/10.1136/bmj.i2343 (Published 11 May 2016) Cite this as: BMJ 2016;353:i2343
- Maryam S Farvid, visiting scientist, research associate1 2,
- Wendy Y Chen, assistant professor3 4,
- Karin B Michels, associate professor3 5 6,
- Eunyoung Cho, associate professor3 7,
- Walter C Willett, professor1 3 5,
- A Heather Eliassen, associate professor3 5
- 1Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston, MA, USA
- 2Harvard/Massachusetts General Hospital Center on Genomics, Vulnerable Populations, and Health Disparities, Mongan Institute for Health Policy, Massachusetts General Hospital, Boston, MA, USA
- 3Channing Division of Network Medicine, Department of Medicine, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA, USA
- 4Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
- 5Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA, USA
- 6Obstetrics and Gynecology Epidemiology Center, Department of Obstetrics, Gynecology and Reproductive Biology, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA
- 7Department of Dermatology, The Warren Alpert Medical School of Brown University, Providence, RI, USA
- Correspondence to: M S Farvid
- Accepted 12 April 2016
Objective To evaluate the association between fruit and vegetable intake during adolescence and early adulthood and risk of breast cancer.
Design Prospective cohort study.
Setting Health professionals in the United States.
Participants 90 476 premenopausal women aged 27-44 from the Nurses’ Health Study II who completed a questionnaire on diet in 1991 as well as 44 223 of those women who completed a questionnaire about their diet during adolescence in 1998.
Main outcome measure Incident cases of invasive breast cancer, identified through self report and confirmed by pathology report.
Results There were 3235 cases of invasive breast cancer during follow-up to 2013. Of these, 1347 cases were among women who completed a questionnaire about their diet during adolescence (ages 13-18). Total fruit consumption during adolescence was associated with a lower risk of breast cancer. The hazard ratio was 0.75 (95% confidence interval 0.62 to 0.90; P=0.01 for trend) for the highest (median intake 2.9 servings/day) versus the lowest (median intake 0.5 serving/day) fifth of intake. The association for fruit intake during adolescence was independent of adult fruit intake. There was no association between risk and total fruit intake in early adulthood and total vegetable intake in either adolescence or early adulthood. Higher early adulthood intake of fruits and vegetables rich in α carotene was associated with lower risk of premenopausal breast cancer. The hazard ratio was 0.82 (0.70 to 0.96) for the highest fifth (median intake 0.5 serving/day) versus the lowest fifth (median intake 0.03 serving/day) intake. The association with adolescent fruit intake was stronger for both estrogen and progesterone receptor negative cancers than estrogen and progesterone receptor positive cancers (P=0.02 for heterogeneity). For individual fruits and vegetables, greater consumption of apple, banana, and grapes during adolescence and oranges and kale during early adulthood was significantly associated with a reduced risk of breast cancer. Fruit juice intake in adolescence or early adulthood was not associated with risk.
Conclusion There is an association between higher fruit intake and lower risk of breast cancer. Food choices during adolescence might be particularly important.
The study sponsors were not involved in the study design and collection, analysis and interpretation of data, or the writing of the article or the decision to submit it for publication. The authors were independent from study sponsors. We thank the participants and staff of the NHS II for their valuable contributions as well as the following state cancer registries for their help: AL, AZ, AR, CA, CO, CT, DE, FL, GA, ID, IL, IN, IA, KY, LA, ME, MD, MA, MI, NE, NH, NJ, NY, NC, ND, OH, OK, OR, PA, RI, SC, TN, TX, VA, WA, WY.
Contributors: All authors designed the research, provided critical input in the writing of the manuscript, and read and approved the final version of manuscript. MSF carried out the analysis and wrote the manuscript. MSF and AHE are guarantors.
Funding: The study was supported by the National Institutes of Health Grants (R01 CA050385, UM1 CA176726) and a grant from The Breast Cancer Research Foundation. MSF was supported by the Japan Pharmaceutical Manufacturers Association.
Competing interests: All authors have completed the ICMJE uniform disclosure form at www.icmje.org/coi_disclosure.pdf (available on request from the corresponding author) and declare: no support from any organization for the submitted work; no financial relationships with any organizations that might have an interest in the submitted work in the previous three years, no other relationships or activities that could appear to have influenced the submitted work.
Ethical approval: The study protocol (IRB protocol No 1999-P-003389) was approved by the institutional review boards of Brigham and Women’s Hospital and Harvard School of Public Health (Boston, MA). The completion of the self administered questionnaire was considered to imply informed consent.
Data sharing: No additional data available.
Transparency: The lead authors affirm that the manuscript is an honest, accurate, and transparent account of the study being reported; that no important aspects of the study have been omitted; and that any discrepancies from the study as planned (and, if relevant, registered) have been explained.
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