Maternal diet and exercise: effects on long-chain polyunsaturated fatty acid concentrations in breast milk

Long-chain polyunsaturated fatty acids (LC-PUFA) are essential for infant growth and development. The amount of long-chain PUFA in breast milk depends on maternal diet and body stores. Because exercise increases mobilization and utilization of fatty acids, maternal activity may also influence the amount of LC-PUFA in breast milk.

To investigate the effects of exercise on alpha-linolenic acid (LNA), linoleic acid (LA), docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), and arachidonic acid (AA) concentrations in maternal plasma and breast milk and to determine if lactating women consume adequate amounts of LC-PUFA to compensate for those used for energy during exercise.

LC-PUFA in plasma and breast milk were measured at 12 weeks postpartum in exercising and sedentary women. Dietary intake was recorded for 3 days. A subsample of women participated in exercise and rest sessions to examine the acute effects of exercise on breast milk LC-PUFA.

There were no differences in dietary intake between the two groups. Mean intake (+/-standard error of the mean) of LA was 11.05+/-1.39 and 9.34+/-0.97 and LNA was 0.96+/-0.12 and 0.82+/-0.09 g/day by the sedentary and exercise groups, respectively. These amounts are close to the Adequate Intakes of LA and LNA for lactation (13 and 1.3 g/day, respectively). No differences were found in LC-PUFA in plasma and breast milk between groups. After 30 minutes of exercise, there was a trend for an increase in LA and LNA concentrations in breast milk, with no change in DHA, EPA, and AA concentrations.

These results suggest that women consuming adequate amounts of LC-PUFA can exercise moderately without decreasing the LC-PUFA in their breast milk.