Breastfeeding appears to negatively correlate with breast cancer incidence, thus suggesting a protective effect, according to a recently published study in the International Breast Feeding Journal.
Breast cancer remains the most prevalent malignancy among women globally, accounting for approximately 2.26 million new cases and 685,000 deaths in 2020 alone. While advancements in detection have improved prognoses in high-income regions, the disease continues to impose a staggering burden in low- and middle-income countries where access to screening and treatment is often restricted.
In this context, hormonal and reproductive factors have emerged as critical areas of focus for prevention, with breastfeeding identified as a significant, modifiable protective factor.
Physiologically, lactation acts to suppress ovulation, thereby reducing a woman’s cumulative lifetime exposure to estrogen, which is a well-established determinant of breast carcinogenesis. Beyond hormonal regulation, the process of breastfeeding promotes the differentiation of breast tissue and increases the turnover of epithelial cells.
To evaluate the strength of this association, researchers conducted a meta-analysis , searching the Scopus, PubMed, and EBSCO databases for observational studies published between 2014 and 2024.
The pooled results from 20 studies revealed that women who have never breastfed have a 40% higher risk of developing breast cancer compared to those with a history of breastfeeding. The duration of lactation significantly influenced this protective potential, with shorter periods conferring higher risk. Specifically, breastfeeding for less than 12 months was associated with a 3.59-fold greater risk of breast cancer when compared to breastfeeding for more than 11 months.
The study benefited from a substantial total sample size of more than 22,631 breast cancer patients and 38,873 controls across diverse geographic areas, which improved the precision and generalizability of the findings.
“This meta-analysis supports the protective effect of extended breastfeeding against breast cancer, particularly for durations exceeding 11 months,” the authors wrote.” These findings underscore the importance of promoting breastfeeding as an accessible and cost-effective preventive strategy, particularly in resource-constrained settings,”
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