HIGHER breastfeeding intensity may be associated with a healthier lipid profile in women with a history of gestational diabetes, according to new research.
The prospective cohort study, involving 470 women in Japan, found that high-intensity breastfeeding was associated with lower triglycerides, higher high-density lipoprotein cholesterol (HDL-C), and a lower low-density lipoprotein cholesterol (LDL-C) to HDL-C ratio during the early postpartum period.
Women with a history of gestational diabetes face an increased risk of cardiometabolic conditions, including dyslipidaemia and cardiovascular disease. Researchers therefore investigated whether breastfeeding intensity was associated with lipid profiles shortly after pregnancy.
The study included Japanese women with singleton pregnancies complicated by gestational diabetes who underwent metabolic assessments 6–9 weeks after giving birth. Breastfeeding was assessed using a six-level scale based on the proportion of breast milk in the infant’s diet
High-intensity breastfeeding was defined as breast milk accounting for at least 80% of infant feeding. Overall, 369 of the 470 participants (79%) met this threshold.
Dyslipidaemia, an abnormal or unhealthy level of lipids in the blood, was common in the study population, affecting 74% of participants. More than half (57%) had high LDL-C, while 9% had hypertriglyceridaemia and 18% had an elevated LDL-C to HDL-C ratio.
Women practicing high-intensity breastfeeding had mean triglyceride levels of 67.2 mg/dL, compared with 116.1 mg/dL amongst women with lower breastfeeding intensity.
Mean HDL-C levels were also higher, at 73.9 mg/dL versus 63.0 mg/dL, while the mean LDL-C to HDL-C ratio was lower at 1.8 versus 2.3.
Researchers also observed a dose-response pattern across the six breastfeeding categories. As breastfeeding intensity decreased, triglyceride levels and the LDL-C to HDL-C ratio progressively increased, while HDL-C decreased.
After adjusting for factors including maternal age, pre-pregnancy BMI, postpartum weight, fasting glucose, and insulin sensitivity, high-intensity breastfeeding remained associated with 69% lower odds of hypertriglyceridaemia and 69% lower odds of an elevated LDL-C to HDL-C ratio.
The association between high-intensity breastfeeding and lower odds of high LDL-C, however, was no longer statistically significant after adjustment for insulin sensitivity.
The researchers suggested that lactation could influence lipid metabolism through mechanisms including increased energy expenditure and mobilisation of maternal fat stores. Notably, the associations persisted after accounting for insulin sensitivity, suggesting other mechanisms may also contribute.
However, as an observational study, the findings cannot establish that breastfeeding directly caused the improved lipid profiles. Breastfeeding practices were also self-reported, and participants were recruited from a single tertiary centre in Japan, potentially limiting the generalisability of the findings.
The authors conclude that supporting breastfeeding may have a role in postpartum care for women at elevated cardiometabolic risk. Further longitudinal research is needed to determine whether the favourable lipid profiles observed shortly after pregnancy persist and ultimately translate into reduced cardiovascular disease risk.
Reference
Kanzawa H et al. Breastfeeding Intensity and Early Postpartum Lipid Profiles Among Women With Prior Gestational Diabetes. JAMA Netw Open. 2026;9(8).
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