A carbohydrate-rich diet not only leads to incorporation of medium-chain fatty acids (6:0-14:0) in milk triglycerides but also in each milk-phospholipid subclass

ABSTRACT

We isolated phospholipid (PL) subclasses from milk of women in Dominica and Belize. Fatty acid (FA) compositions of PLs and total lipids were determined. In the total-lipid fraction Dominican milk showed higher relative amounts of medium-chain saturated fatty acids (MC-SAFAs; 60-140) and 226n-3 and lower amounts of long-chain saturated fatty acids (LC-SAFAs) and monounsaturated fatty acids (MUFAs). There was a positive relationship between the MC-SAFA content in total lipids and total PLs. Incorporation of MC-SAFAs in PLs occurred at the expense of LC-SAFAs, MUFAs, polyunsaturated fatty acids (PUFAs), and long-chain PUFAs with o20 carbon atoms (LC-PUFAs oC20). Previous studies from western countries revealed low amounts of MC-SAFAs and high amounts of PUFAs and LC-PUFAs oC20 in milk PLs. Our data show that carbohydrate-rich diets give rise to incorporation of MC-SAFAs in PLs at the expense of PUFAs and LC-PUFAs oC20. The data are discussed in relation to the presumed origin of fat-globule membrane phospholipids. (AU)