MATERNAL SMOKING HABITS AND FATTY ACID (FA) COMPOSITION OF HUMAN MILK THROUGH 12 MONTHS OF LACTATION

Giovannini M, Agostoni C, Scaglioni S, D�Auria E, Riva E, Banderali G

Department of Pediatrics, San Paolo Hospital, Milan, Italy

Objective: To investigate the relation between maternal smoking habits and milk FA composition.

Methods: Observational study on 95 mothers who gave birth to healthy, full-term infants and were recruited in order to estimate their milk FA content and composition through 12 months of lactation. A mother was defined as a regular smoker (S) if consuming >5 cigarettes per day before being aware to be pregnant. Pooled hindmilk was collected over 24 hours at basal time (colostrum), 1 mo, 3 mos, 6 mos, 9 mos and 12 mos. Total lipids (TL) were measured with microgravimetrc method while milk FA were analysed with high-resolution capillary gas-chromatography. Statistics by non-parametric tests.

Results: Among mothers, 62 were non-smokers (non-S) and 33 smokers (S). Mothers still breastfeeding progressively decreased to 67 (46 non-S, 21 S) at 1 mo, 54 (38 non-S, 16 S) at 3 mos, 31 (22 non-S, 9 S) at 6 months, 16 (11 non-S, 5 S) at 9 months, 10 (7 non-S, 3 S) at 12 months. TL content of colostrum was similar (16 g/L) in the two groups. A great within-group variability in milk fat content and composition was found afterwards. Milk TL were higher in non-S mothers' milk at 1 mo (P=0.06) and S mothers' milk at 9 mos (P=0.10) and 12 mos (P=0.03). As a consequence of the parallel changes in TL content and % FA levels, the S-mothers' milk content (mg/L) of linoleic acid and alpha-linolenic acid was lower at 1 month (P=0.10 and P=0.08, respectively) and higher in the 9-12 month period vs non-S mothers�� milk. A similar trend was found also for the arachidonic and docosahexaenoic acid content.

Conclusion: Milk fat content and composition through lactation may be affected by maternal smoking habits.

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