Dietary soy intake and breast cancer risk.
OBJECTIVE
To conduct a metasynthesis of the literature on human studies of the relationship between dietary soy intake and breast cancer risk.


METHODS
Publications in English reporting human studies were searched with the terms soy and breast cancer, using Ovid, PubMed, and EBSCO databases. Only human studies investigating the relationship of soy intake to breast cancer development in women published from January 1997 through June 2008 were included in the review.


RESULTS
A total of 364 publications were located; 18 of the studies met the inclusion criteria and 18 additional studies were located through other publications identified in the search. Because four articles reported on the same two studies, a total of 34 studies were included in the review.


CONCLUSIONS
The naturally occurring dietary intake of soy food or its components appears safe for women without breast cancer; however, the safety of high supplements of soy or its components is less certain.


CONCLUSIONS
Nurses should become more knowledgeable about soy foods and supplements and include soy intake in dietary assessments. Nurses caring for women at high risk for or with a history of breast cancer should confer with dietitians on current practice recommendations. Women with health issues should avoid initiating high intake of soy dietary supplements until the possible effects are better understood.
Enderlin
Carol A
CA
Department of Nursing Education, College of Nursing, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA. caenderlin@uams.edu
Coleman
Elizabeth Ann
EA
Stewart
Carol Beth
CB
Hakkak
Reza
R
D001943:Breast Neoplasms / Q000453:epidemiology / Q000517:prevention & control*; D004967:Estrogens / Q000494:pharmacology; D005260:Female; D014943:Global Health; D006801:Humans; D007529:Isoflavones / Q000494:pharmacology; D044469:Racial Groups / Q000706:statistics & numerical data; D012307:Risk Factors; D045730:Soy Foods; D013025:Glycine max / Q000737:chemistry
D004967:Estrogens; D007529:Isoflavones