BREAST-MILK FATTY-ACID COMPOSITION - A COMPARATIVE-STUDY BETWEEN HONG-KONG AND CHONGQING CHINESE

The fatty acids of milk samples obtained from 51 Hong Kong Chinese and 33 Chongqing Chinese (Si Chuan Province, China) were analyzed by gas- liquid chromatography. Compared with those of published data for Canad ian and other Western countries, the Chinese milk from both Hong Kong and Chongqing contained higher levels of longer-chain polyunsaturated fatty acids, particularly docosahexaenoic acid (22:6n-3) and arachidon ic acid (20:4n-6). In contrast, the content of trans fatty acids in th e Chinese milk was lower compared with those for Canadian and other We stern countries. Longitudinally, the concentrations of 22:6n-3 and 20: 4n-6 gradually decreased when lactation progressed from colostrum (wee k 1) to mature (week 6). Over the same interval, linoleic acid (18:2n- 6) remained unchanged in Chongqing Chinese but significantly increased in Hong Kong Chinese. Unlike 18:2n-6, linolenic acid (18:3n-3) increa sed in Chongqing Chinese but remained unchanged in Hong Kong Chinese t hroughout the study. The total milk fat also increased with the durati on of lactation. In addition, the milk of Chongqing Chinese had higher total milk fat than that of Hong Kong Chinese and Canadians. The cont ent of erucic acid (22:1:n-9) increased with the progression of lactat ion in Chongqing Chinese, indicating that there was a switch in dietar y consumption from fats of animal origin to rapeseed oil when lactatio n reached week 6. The present study showed that Hong Kong and Chongqin g Chinese had a different fatty acid profile in many ways, which large ly reflected a different dietary habit and life-style in these two pla ces.