Long‐chain polyunsaturated fatty acids in human milk and brain growth during early infancy

Abstract

Long‐chain polyunsaturated fatty acids are essential for growth and development, and their crucial role in the development of the central nervous system and in retinal function has been the subject of many studies. As the balance between n‐6 and n‐3 fatty acids has to be optimal, their concentrations in the milk given to infants who are exclusively breastfed is of major importance. In this study, the composition of fatty acids in mothers' milk and the growth rate of the infant brain were analysed. Nineteen mother‐term infant pairs from Stockholm, Sweden, were studied from birth to 1 mo and 3 mo of age, during which time the infants were breastfed exclusively. The dietary intake of the mothers was calculated and found to concur with the recommended daily dietary allowances of Swedish lactating women as regards energy, protein, fat and carbohydrates. The amounts of linoleic acid and α‐linolenic acid in the diet were similar to those reported for European and North American women. The ratio between arachidonic acid (AA) and docosahex‐aenoic acid (DHA) in the milk from Swedish mothers is approximately the same as in the brain of infants, and was found to be positively correlated with the rate of gain of the occipito‐frontal head circumference and of the calculated brain weight at 1 mo (p < 0.01) and 3 mo (p < 0.01) of age, respectively. However, further studies are needed to establish the exact requirements of AA and DHA for optimal growth and development during early infancy in exclusively breastfed infants.

Temporal Changes of Human Breast Milk Lipids of Chinese Mothers

“…Chinese studies have reported SFA level in colostrum ranging from 36.8% to 41.3% [30,31], in transitional milk from 35.2% to 42.6% [31,32] and in mature milk from 35.1% to 41.1% [30,31,32,33,34], in agreement with our results. When considering other populations (e.g., Caucasian, American) the SFA level in colostrum was 42.3%–43.7% [35,36,37], in transitional milk it ranged from 43.1% to 45.2% [36,37] and, in mature milk, from 37.4% to 57.1% [34,35,36,37,38], therefore, Chinese populations seem to show lower amount of total SFA in colostrum, transitional and mature milk when compared to other populations. …”

“…Among the Chinese population, lauric, myristic, palmitic, and stearic acids ranged between 3.0%–4.9%, 5.2%–5.3%, 20.1%–23.3%, and 6.0%–7.0% of total FA, respectively, in colostrum [30,31]; between 4.2%–6.5%, 3.8%–6.4%, 19.7%–23.3%, and 5.4%–8.1% of total FA, respectively, in transitional milk [31,32]; and finally between 3.8%–6.3%, 3.4%–6.5%, 17.3%–22.3%, and 5.0%–8.0% of total FA, respectively, in mature milk [30,31,32,33,34]. When considering other populations, lauric, myristic, palmitic, and stearic acids ranged between 1.2%–4.5%, 4.8%–7.3%, 24.0%–27.3%, and 5.5%–7.1% of total FA, respectively, in colostrum [35,36,37]; between 5.2%–6.5%, 6.5%–7.7%, 22.2%–22.6%, and 5.7%–7.4% of total FA, respectively, in transitional milk [36,37]; and finally between 3.7%–6.1%, 4.9%–7.0%, 18.7%–23.0%, and 4.8%–7.6% of total FA, respectively, in mature milk [34,35,36,37,38]. Philippian population showed high lauric (13.82%) and myristic (12.12%) FA contents [34] and it was reported [20,21] that 10:0, 12:0, and 14:0 FA content increases when lactating women consumed high-carbohydrate diets, whereas the secretion of the 18-carbon chain unsaturated FA, which are derived from the diet, decreased.…”

“…When considering other population, MUFA levels in colostrum ranged between 32.1%–44.4% of total FA [35,36,37], in transitional milk it was 35.1% of total FA [37], and in mature milk ranged from 30.3%–44.4% of total FA [34,35,37,38], therefore, Chinese populations seem to show comparable MUFA content in colostrum, transitional and mature milk to other populations.…”

“…In the Chinese population oleic acid ranged from 28.4%–36.3% of total FA in colostrum [30,31]; from 25.9%–36.5% of total FA in transitional milk [31,32], and from 24.9%–38.1% in mature milk [30,31,32,33,34], and in other populations from 28.4%–40.1%, from 27.7%–32.1%, and from 21.9%–40.5% of total FA in colostrum [35,36,37], transitional [36,37], and mature milk [34,35,36,37,38], respectively.…”

“…When considering other populations, PUFA levels in colostrum ranged between 11.2%–14.0% for n -6PUFA and from 1.9%–3.5% of total FA for n -3PUFA [35,36,37], in transitional milk from 12.3%–14.1% for n -6PUFA and from 1.5%–3.3% of total FA for n -3PUFA [36,37], and in mature milk from 9.5%–20.3% for n -6PUFA and from 1.3%–3.2% of total FA for n -3PUFA [34,35,36,37,38]. Therefore, the Chinese populations seem to show higher contents of total n -6 PUFA when compared to other populations.…”