Omega 3 Fatty Acids in Breastmilk and Infant Temperament
by Anne Eglash MD, IBCLC, FABM
Omega-3 polyunsaturated fatty acids (PUFAs) in breastmilk have been identified as one of the reasons for higher IQ and earlier brain and eye development in breastfed infants vs those who are formula fed. There are several different types of omega-3 PUFAs, but the most important and abundant ones in human milk are alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexanoic acid (DHA). Of these 3, DHA is the most abundant and important omega-3 PUFA for brain development. The concentration of omega-3 PUFAs in breastmilk depends on the maternal diet.
The authors of the today’s article report that there is plenty of circumstantial evidence among humans and animals that deficiencies of omega-3 PUFAs can contribute to anxiety and mood disorders. There have not been any studies investigating the relationship between omega-3 PUFAs in breastmilk and infant behavior- this research has so far only been done in rats. They cite one study that fed pregnant rats a diet deficient in omega-3 PUFAs, and found that the rat pups had more anxiety-like behavior.
The researchers of this week’s study collected milk samples from 52 mothers of 3-month old infants. The milk was assessed for omega-3 PUFA levels. The mothers completed an infant temperament survey called the Rothbart Revised Infant Behavior Questionnaire. The study was controlled for a number of maternal and infant characteristics such as maternal age, marital status, infant gestation age, birth weight, etc. They did not ask the parents about their own mental health histories.
The authors found that higher amounts of omega-3 PUFAs in breastmilk were associated with less infant negative affectivity, ALA more so than DHA and EPA. Negative affectivity refers to the infant’s tendency to react to stressors with anger, irritability, fear, or sadness.
- Fatty fish, such as salmon and mackerel, are the best sources for DHA.
- Walnuts and flaxseeds are excellent substitutions for fatty fish because of their high DHA content.
- The best non-fish sources of DHA are seaweed and algae.
- Chia seeds have a lot of omega-3 PUFAs that are ALA, not DHA.
- Soybeans are high in ALA.
See the Answer
There is growing evidence that omega-3 (n-3) polyunsaturated fatty-acids (PUFAs) are important for the brain development in childhood and are necessary for an optimal health in adults. However, there have been no studies examining how the n-3 PUFA composition of human milk influences infant behavior or temperament. To fill this knowledge gap, 52 breastfeeding mothers provided milk samples at 3 months postpartum and completed the Infant Behavior Questionnaire (IBQ-R), a widely used parent-report measure of infant temperament. Milk was assessed for n-3 PUFAs and omega-6 (n-6) PUFAs using gas-liquid chromatography. The total fat and the ratio of n-6/n-3 fatty acids in milk were also examined. Linear regression models revealed that infants whose mothers’ milk was richer in n-3 PUFAs had lower scores on the negative affectivity domain of the IBQ-R, a component of temperament associated with a risk for internalizing disorders later in life. These associations remained statistically significant after considering covariates, including maternal age, marital status, and infant birth weight. The n-6 PUFAs, n-6/n-3 ratio, and total fat of milk were not associated with infant temperament. These results suggest that mothers may have the ability to shape the behavior of their offspring by adjusting the n-3 PUFA composition of their milk.
Foods that are high in ALA omega-3 PUFAs include chia seeds, walnuts, flaxseeds, hemp, soybeans, canola oil, and kidney beans. Fish is the best dietary source of DHA, with fatty fish, such as mackerel, salmon and sardines, being the best choices. Seaweed and algae are the best non-fish sources of DHA. However, in this study, ALA levels had a stronger association with less infant negative affectivity.
This study is admittedly small and does not control for parental mental health, so its clinical applicability is limited, and more research is needed. However, if a mother asks whether she should eat certain foods during pregnancy and lactation for her infant’s health, we know for certain that 2-3 servings a week of fish or seaweed are important for fetal and infant brain development. It cannot hurt to also advise plenty of other omega-3 fatty acids, those high in ALA, since these are foods that have high nutritional impact as well.
For an excellent fact sheet on Omega-3 Fatty Acids to give to your clients/patients, visit the National Institutes of Health Omega-3 Fatty Acid Fact Sheet for Consumers.