Cholesterol, phytosterols, and polyunsaturated/saturated fatty acid ratios during the first 12 months of lactation

Abstract

Maternal diet, plasma, and breast milk, and infant plasma cholesterol, phytoster- ohs, and polyunsaturated/saturated fatty acid (P/S) ratios were studied cross-sectionally in 33 normal women and in one woman homozygous for familial hypercholesterolemia during the 1st year of lactation. In the normal women, breast milk cholesterol levels varied from 2.2 to 13.3 mg cholesterol per gram milk fat; a 30% variation in breast milk cholesterol within the same subject from month to month was not unusual. Mean milk cholesterols during the first 12 months of lactation were respectively 20.1, 19.5, 19.7, 22.0, 15.6, 28.3, 28.1, 22.0, 26, 21.1, 13.5, and 15.1 mg/ 100 ml. The range of habitual dietary cholesterol and P/S intake in the normal mothers was 423 to 517 mg/day, and 0.14 to 0.46, respectively. Mean (± SE) maternal milk cholesterol levels for all normal subjects were 5.7 ± .3 mg/g milk fat for both the first 6 months of lactation and 6.0 ± .4 for months 7 to 12. Breast milk phytosterol levels and P/S ratios were also very comparable for the first and second 6-month periods of lactation being respectively 1.7 ± .3 and 1.7 ± .3 mg/g breast milk, and 0.37 ± 0.02 and 0.33 ± 0.02. In the first 7 months lactation, the homozygous familial hypercholesterolemic's breast milk had a 16-fold enrichment with cholesterol, with levels ranging from 93 to 319 mg/lOO ml of milk. Maternal milk cholesterol did not correlate with infant plasma cholesterol, nor did milk phytosterol correlate with infant plasma phytosterol levels. Maternal dietary polyunsaturated to saturated fatty acid ratios inversely related to maternal plasma choles- terol. Maternal plasma phytosterol and P/S levels both were positively associated with breast milk phytosterol and P/S levels. Alteration of maternal diet can thus ultimately lead to alteration of breast milk phytosterol (but not cholesterol content), and to alteration of P/S ratios. Am. J. Clin. Nuir. 32:2383-2389, 1979.