Egg consumption and breast cancer risk: a meta-analysis

The relationship between egg consumption and breast cancer risk has been inconsistent, so it is necessary to conduct a meta-analysis to evaluate the relationship. PubMed, EMBASE and ISI Web of Knowledge were searched to find cohort studies or case control studies that evaluated the relationship between egg consumption and breast cancer risk. A comprehensive meta-analysis software was used to conduct the meta-analysis. 13 studies were included. The meta-analysis results showed that egg consumption was associated with increased breast cancer risk (RR 1.04, 95 % CI 1.01-1.08). Subgroup analyses showed egg consumption was also associated with increased breast cancer risk based on cohort studies (RR 1.04, 95 % CI 1.00-1.08), among European population (RR 1.05, 95 % CI 1.01-1.09), Asian population (RR 1.09, 95 % CI 1.00-1.18), postmenopausal population (RR 1.06, 95 % CI 1.02-1.10), and those who consumed a parts per thousand yen2, a parts per thousand currency sign5/week (RR 1.10, 95 % CI 1.02-1.17), but not in case-control studies (RR 1.06, 95 % CI 0.97-1.15), among American population (RR 1.04, 95 % CI 0.94-1.16), premenopausal population (RR 1.04, 95 % CI 0.98-1.11) and those who consumed a parts per thousand yen1, < 2/week (RR 1.04, 95 % CI 0.97-1.11) or > 5 eggs/week (RR 0.97, 95 % CI 0.88-1.06). Egg consumption was associated with increased breast cancer risk among the European, Asian and postmenopausal population and those who consumed a parts per thousand yen2, a parts per thousand currency sign5/week.