Any breastfeeding, regardless of duration or exclusivity, is associated with lower blood pressure at 3 years of age

Article Title: Breastfeeding in the First Days of Life is Associated with Lower Blood Pressure at 3 Years of Age
Journal: Journal of the American Heart Association
Date: August 3, 2021

Summary:
The results of this large prospective cohort study shows that any amount of breastfeeding ever, including early and limited breastfeeding in the first days of life, is associated with lower blood pressure at 3 years of age - independent of many potential maternal and infant confounding variables. The size of the observed effect in this study is substantial (3.5 mm Hg higher blood pressure in never breastfed children). Given that blood pressure tracks from childhood into adulthood, this finding suggests that supporting the initiation of breastfeeding could have substantial impacts on cardiovascular disease prevention later in life, and that regardless of duration or exclusivity, being breastfed – even if only in the first days postnatal - confers important health benefits.

A novel aspect of this study is that researchers assessed infant feeding in the first days of life, something not typically captured in other birth cohort studies. Using feeding data from hospital records, they included infants who were “ever breastfed”, meaning those who received even a relatively small amount of their mother’s early breast milk (colostrum). Researchers also included infants who were “never breastfed”, meaning there was no attempt to breastfeed while in the hospital or at home, as a comparison group.

Previous studies that have looked at the association between breastfeeding and blood pressure either

• excluded mothers who did not initiate breastfeeding in the hospital (“never breastfed”), or
• excluded those mother/baby dyads that breastfed only during their hospital stay (“ever breastfed”). 

The exclusion of hospital feeding data from previous studies might explain prior conflicting results regarding the association of breastfeeding and blood pressure. The authors speculate this may be due to the potential misclassification of “ever breastfed” infants. For example, researchers in this current study found 98 mothers who reported “never breastfeeding” but had actually provided early, limited breastfeeding during the neonatal period at the hospital. Such a misclassification would not affect results if sustained breastfeeding was required to affect the outcome of interest. But if early and limited breastfeeding is enough to affect the outcome, such as the association with lowered blood pressure at age 3, it’s critical to capture and consider very early feeding.  

Key takeaways/Why this is important:
Evidence suggests that risk factors for poor cardiovascular health (including high blood pressure), trace back to childhood and are influenced by early life exposures. There are many biological reasons why consuming early breast milk (colostrum) during the first days of life could influence cardiovascular health:

• Early breastfeeding strongly affects the colonization and composition of the intestinal microbiome.
  • Early research indicates an altered microbiota may be involved in promoting the formation of plaque in the arteries.
• Nutrients and bioactive components that are enriched in colostrum, such as stem cells and vascular endothelial growth factor, may have long-lasting developmental benefits.
• Colostrum is rich in high concentrations of n-3 long-chain polyunsaturated fatty acids, which are important structural components of the vascular endothelium (inner lining of arteries, veins and capillaries).
• Even relatively small elevations in blood pressure could predispose young children to hypertension later in adulthood.

Implications:
The findings from this study have important implications for individual and public health. The researchers emphasize the importance of prenatal education and immediate postpartum lactation support to help women initiate breastfeeding, so more infants receive colostrum.

This study’s findings are also relevant to health care practice and policy. Hospitals that implement cost-cutting strategies like discharging a new mother within 24 hours of having a vaginal delivery, and eliminating lactation support services on post-partum units, may see short-term savings. However, those savings could be greatly outweighed by the delayed cost burden of future cardiovascular disease. 

Note: many other studies have shown sustained and exclusive breastfeeding confers many more health benefits for both mother and baby. For babies, this includes increased protection against obesity, asthma, Type 1 diabetes, SIDS, ear infections, gastrointestinal distress and more. For mothers, it lowers her risk for high blood pressure, Type 2 diabetes, ovarian cancer and breast cancer. There are also well-documented psychological, neurological and emotional benefits to exclusive and sustained breastfeeding. Current American Academy of Pediatrics recommendations call for exclusive breastfeeding for the first six months, and then continued breastfeeding while introducing complementary foods until 12 months or older.

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The OHSU Bob and Charlee Moore Institute for Nutrition & Wellness supports human research that seeks to find the links between maternal stresses, including poor nutrition, and elevated disease risks for babies as they become adolescents and adults.

Miliku, K., Moraes, T.J., Becker, A., Mandhane, P.J., Sears, M.R., Turvey, S.E., Subbarao, P., Azad, M.B., (2021). Breastfeeding in the first days of life is associated with lower blood pressure at 3 years of age. Journal of the American Heart Association, 10(15), e019067 https://doi.org/10.1161/JAHA.120.019067