Breast milk docosahexaenoic acid levels from dried vs. liquid samples from mothers in Bangladesh and Malawi (1015.2)

Abstract

The effect of breast milk DHA (22:6n‐3) levels on infant health outcomes is unclear. Difficulties in collecting, storing and shipping samples from the field impede research in this area. Here, DHA levels in dried milk spots (DMS) and liquid milk (LM) from the same subjects were compared, then milk samples collected by both methods from Malawi and Bangladesh were tested. Validation studies used milk spots (n=5) dried on cards pretreated with an antioxidant (OxyStop®) and stored in the dark for 4 wks at 23°C or at ‐80°C; LM samples were also tested after storage for 1.5 yrs at ‐20°C. DMS samples from 685 Bangladeshi mothers were shipped ambient, and frozen LM samples from 763 Malawian mothers were shipped on dry ice for analysis. Maternal dietary information was not available in either study. DHA levels in LM vs. DMS from the same subjects were strongly correlated (r>0.99; p<0.0001). The DHA content of DMS was unchanged from baseline after 4 weeks at 23°C (0.19±0.14% vs. 0.20±0.15%). Similarly, LM DHA content was stable over 1.5 years at ‐20°C (0.16±0.15% vs. 0.19±0.15%). Malawian mothers had higher milk DHA levels than Bangladeshi mothers (0.73±0.38% vs. 0.39±0.14%; p<0.0001). Breast milk samples can be collected and shipped as DMS without loss of DHA. Differences in milk DHA levels between Malawi and Bangladesh were not due to differences in method of collection. These results suggest a higher DHA intake in mothers in Malawi.