Let’s pose a question: if you were told your child would have greater attention, less distractibility and hyperactivity, and greater cognitive development as a 5 year old, based on what he or she received through pregnancy and feeding, would you listen?
That is a rhetorical question. Of course you would.
What if the most important nutrients for brain development in children were under direct influence of maternal diet?
The highest concentration of the long-chain polyunsaturated fatty acids (LCPUFA’s) docosahexaenoic acid (DHA) and arachidonic acid (AA) is in the brain (1).
Research suggests that the maternal diet and fatty acid composition of breast milk may be critically important to infant cognitive development (2).
While AA is vital to infant brain development, even across populations with very different dietary patterns, AA intake through diet and the AA content of breastmilk remain relatively constant (3).
This is consistent with dietary fatty acids generally, with one notably exception: DHA (3).
In fact, the DHA content of breastmilk directly corresponds to the intake of DHA through diet (3). Increasing maternal consumption of DHA leads to dose-dependant increases in breastmilk DHA content (4).
This is of pivotal importance to the child’s cognitive development. Recall from the previous article that conversion of the 18-carbon omega-3 fatty acid, alpha linolenic acid (ALA), to DHA in humans is minimal.
This mandates a requirement for preformed DHA, without reliance on conversion of ALA, as preformed DHA is preferentially incorporated into brain cells with greater efficiency than fatty acids synthesised from ALA (2).
Increased AA intake in breastmilk is easily achievable through consistent dietary egg consumption (4), and AA is vital to infant growth and development in preterm infants (5).
The evidence supporting enhanced visual acuity from DHA is more consistent in pre-term infants than infants born at term (6).
This may be explained by the fact that rapid DHA and AA accumulation in the brain begins to occur during the last trimester, continuing through the first two years of life (7).
As a result, there is a greater likelihood of observing an effect of DHA on preterm infants that are deprived of increased DHA accumulation in the brain during the last trimester (6).
Different testing methodologies may be responsible for inconsistent results in randomised controlled trials. Early trials using subjective outcome measures suggest that enhanced vision from DHA accruing during the first two months of life (8).
Other research suggests enhanced visual acuity at one year from infants fed formula supplemented with DHA (9).
While the actual timeframe of from DHA on visual acuity remains inconsistent, cumulatively the research indicates that these fatty acids are vital for accelerated visual development, particularly within 8-12 weeks of term (6; 8).
It is possible that gestation has a greater influence on cognitive development than breastfeeding; greater umbilical cord DHA stores, not breastmilk DHA, have been associated with increased cognition at 11 months in full-term infants (10).
Increased maternal DHA through supplementation with 600mg per day has been shown to result in longer gestation duration and higher birth weight (11). This is supported by the observation that children born to mothers with higher DHA levels at birth have greater attention capacity and less distractibility at 12 and 18 months of age (12).
In preterm infants, supplementing formula with DHA and AA increases psychomotor development and cognitive testing at 2 years greater than preterm infants fed an non-supplemented formula (13).
In term infants, feeding supplementing formula from birth to 4 months results in better performance on cognitive testing at 10 months, including improved memory, attention and ability to problem-solve in logical sequence (14).
And it would appear that the window to benefit may not be as tight as it seems. In breastfeeding mothers, taking DHA supplements after over 4 months of feeding increases the ability of the child to sustain attention at 5 years of age (15).
The magnitude of effect may be more pronounced in breastfeeding mothers with low dietary DHA intake (15).
Overall, maternal DHA status appears to be the strongest predictor of cognitive development.
Maternal DHA can be augmented by supplementation if the diet is lacking, and supplementation appears to be as effective either through increased maternal stores in breastfeeding (15), or if added through infant formula (14).
The DHA status of the mother appears to be a vital determinant of infant cognitive and visual acuity development (10; 14).
The rapid accumulation of DHA and AA during the last trimester (7), and the fact that high DHA levels lead to longer gestation (11), are indicative of the importance of these fatty acids during this period.
AA levels can be covered through food consumption, specifically eggs, which contain 85mg of AA per yolk. An average of one whole egg per day has been observed in women with high levels of breastmilk AA (4). The increased protein requirement in Irish guidelines per pregnancy can be met by consuming one whole egg per day, so this advice couples both these aims.
The primary consideration is whether someone chooses to consume fish during pregnancy or not. There are concerns over environmental contaminants. PCB’s, or polychlorinated bisphenyls, are a class of industrial compound that were extensively used up to the 1980’s, but a review of Spanish studies found fish consumption strongly associated with PCB’s in humans (16).
While moderate amounts of fish consumption do not appear to be a problem for non-pregnant populations, there are concerns about potential adverse affects on a developing foetus, given the ability of environmental pollutants to cross the placenta (17).
If you can get freshwater fish high in omega-3 (salmon, herring, farmed trout), then it would be advisable to eat 2 12oz servings per week, but additionally supplement with 300mg DHA per day through pregnancy and lactation (18).
This may also prevent against preterm birth (11).
Should dietary restrictions, environmental considerations or pollution concerns exclude fish, then the strength of the evidence supports supplementation with a direct source of DHA through pregnancy.
The advised dose would be 600mg DHA per day from 20 weeks gestation and through the first 6 months of breastfeeding (11).
For mothers consuming plant based diets, I would recommend this algae oil supplement, taking two doses per day.
If breastfeeding is not an option, keep with the recommendation for 600mg DHA per day from 20 weeks gestation, and make sure that the chosen formula feed containsat least 0.2% DHA and 0.35% AA (19).
Be sure to leave comments or questions on the Facebook page, and I’ll get back to you with answers.
In the meantime, stay well.