Maternal Cholesterol Level During Lactation
by Anne Eglash MD, IBCLC, FABM
Although women tend to have more favorable cholesterol profiles as compared to men, heart disease is still the number one cause of mortality among women. Prolonged high cholesterol during adulthood is a risk factor for heart disease and stroke, yet cholesterol is a vital nutrient for the growing fetus and infant. Cholesterol is essential for cell membrane formation and to manufacture various hormones. Pregnant women have a rise in their cholesterol to meet the lipid needs of the growing fetus, but there is a dearth of evidence regarding lipid profile changes during lactation, especially among populations of color.
The study for this week was part of a larger cohort study, entitled Maternal and Developmental Risks from Environment and Social Stressors (MADRES). This is a prospective pregnancy cohort of low -income, predominantly Hispanic women in Los Angeles, California, established in 2015 to investigate the effects of several environmental and psychosocial risk factors on maternal and infant health outcomes.
The researchers evaluated lipid profiles from 79 women who were 12 months postpartum, in association with their status and duration of breastfeeding. The lipid profiles measured total cholesterol (TC), high density cholesterol (HDL), low density cholesterol (LDL), very low density cholesterol (VLDL) and triglycerides (TG). Lipid profiles are more favorable if the HDL is higher, and the triglycerides, LDL and VLDL are lower.
Of the 79 participants, 35.4% breastfed for <6 months, 30.4% for 6-11 months, and 34.2% were still breastfeeding at 12 months. More than 80% of the participants self-identified as Hispanic, and 65.82% had an annual household income <$30,000.
After controlling for marital status, education, income, fasting status, pre-pregnancy body mass index (BMI), gestational diabetes, type 2 diabetes, glucose intolerance, hypertensive disorders and other pregnancy complications, the researchers found that women who were still breastfeeding at 12 months had a higher HDL, lower VLDL, and lower triglycerides. The total cholesterol and LDL were not significantly different among women no matter their duration of breastfeeding. These changes are associated with a healthier lipid profile.
- Every additional month of breastfeeding is associated with a higher HDL cholesterol (the good cholesterol).
- Every additional month of breastfeeding is associated with a lower triglyceride level.
- Women should be expected to have a higher HDL while actively breastfeeding because of the manufacturing of lipids for breastmilk.
- Women who weaned at 6-11 months postpartum had cholesterol levels that were not significantly different when compared to those who weaned before 6 months postpartum.
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Breastfeeding may protect women’s long-term cardiovascular health; however, breastfeeding related postpartum lipid changes remain unclear. We aim to examine associations of breastfeeding duration with maternal lipids at 12 months postpartum. In a subsample (n = 79) of the Maternal and Developmental Risks from Environmental and Social Stressors (MADRES) cohort, breastfeeding status and duration at 3, 6, and 12 months postpartum were self-reported. Serum levels of lipids, including total cholesterol, triglycerides (TG), high-, low-, and very low-density lipoprotein cholesterol (HDL-C, LDL-C, VLDL-C), were measured from blood samples collected at 12 months postpartum. We used linear regression models to compare lipids by breastfeeding duration, adjusting for potential confounders. Women who were breastfeeding at 12 months had higher HDL-C (mean: 41.74 mg/dL, 95% CI: 37.27–46.74 vs. 35.11 mg/dL, 95% CI: 31.42–39.24), lower TG (80.45 mg/dL, 95% CI: 66.20–97.77 vs. 119.11 mg/dL, 95% CI: 98.36–144.25), and lower VLDL-C (16.31 mg/dL, 95% CI: 13.23, 20.12 vs. 23.09 mg/dL, 95% CI: 18.61–28.65) compared to women who breastfed for 6 months. No lipids were significantly different between women who breastfed for 6–11 months and for < 6 months. Each month’s increase in breastfeeding duration was significantly, inversely associated with TG and VLDL-C and positively with HDL-C. Adjusting for fasting status, demographics, pre-pregnancy body mass index, breastfeeding frequency, and pregnancy complications did not appreciably change effect estimates. Breastfeeding at 12 months postpartum and a longer duration of breastfeeding in the first year postpartum were both associated with increased HDL-C and decreased TG and VLDL-C at 12 months postpartum.
There is extensive evidence that cumulative years of lactation is associated with a decrease in stroke, heart attack, high cholesterol, high blood pressure, type 2 diabetes, metabolic syndrome, and fatty liver disease in women who are well beyond their 5th decade of life. The favorable effect of lactation on serum cholesterol is one mechanism for these improved health outcomes.
The lactating breast is essentially the fountain of youth for women, reversing the negative physiologic consequences of pregnancy. Lactation counseling during the pre-conception and prenatal periods ought to include the metabolic consequences of not lactating. Personally, when I have counseled families who are stressed with difficult breastfeeding situations, I find that partners are very supportive of continued lactation when we discuss the health consequences of premature weaning for the lactating parent.