MedWire News: A study suggests that a lifetime lactation of 2 or more years is associated with a decreased risk for coronary heart disease (CHD) decades later.
“Our findings are consistent with and extend those from earlier reports linking reproductive history to cardiovascular disease risk,” comment Alison Stuebe (University of North Carolina, Chapel Hill, USA) and colleagues.
In their analysis of 89,326 parous women in the Nurses’ Health Study, Stuebe et al found that compared with women who had never lactated, women who had breastfed for 2 or more years had a 37 percent lower risk for CHD after adjusting for age, parity, stillbirth history, early-adult adiposity, parental history, and lifestyle factors.
The authors note that this protective effect is characterized by a threshold effect at 2 years, as women had a hazard ratio (HR) of 0.87 for CHD if they had breastfed for more than 1 year versus no lactation, compared with 0.77 for 2 or more years.
The protective association was found primarily among women who had given birth within the past 30 years compared with those who had not (HR = 0.66 vs 0.90, respectively).
In an accompanying editorial, Erica Gunderson (Kaiser Permanente Northern California, Oakland, California, USA) noted: “An important question that remains unanswered by this study is whether extended duration of lactation for one or two pregnancies confers the same protection as multiple periods of shorter durations for several pregnancies.”
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