More breastmilk, better development

A recent study further explored breastmilk’s effect on infant cognitive and motor development in the French EDEN Mother-Child Cohort Study (J Pediatr 2013; 163: 36-42).

The authors acknowledge that previous studies have shown that breastfed children have  higher scores at tests on cognitive abilities; “however, some authors suggested that these results were due to the difference between the socio-demographic and occupational characteristics of mothers who breastfed and those who did not.”  Though, a large randomized trial (Arch Gen Psychiatry 2008; 65: 578-84) showed convincing data that a  longer duration of exclusive-breastfeeding duration improved children’s cognitive development.

So why did the authors bother with this study? The authors note that few studies have been performed in France where breastfeeding is less common than other European countries and their object of showing a dose-response relationship would further the arguments for causality.

Design: 1387 two-year-olds and 1199 three-year-old children were assessed from the EDEN cohort (2002 pregnancies) which prospectively collected data at birth, 4 months, 8 months,   1 year, and 2 years.

Results:

  • After adjusting for many confounding factors, infants who had breastfed scored 3.7 points higher on the Communicative Development Inventory (CDI) than infants who had never breastfed.
  • Longer breastfeeding duration was associated with better cognitive and motor development in 2- and 3-year-old children.  Each additional month of breastfeeding was associated with an increase of 0.75 CDI points and 1.00 in the Ages and Stages Questionnaire (ASQ).

Take-home message: Most studies, including the present, have shown benefits of breastfeeding on infant development.  In addition, there is likely a dose-response relationship.

Related blog posts:

Avoid breastfeeding to lower the risk of HIV

AAP recommends against breastfeeding infants of HIV-infected mothers:

http://pediatrics.aappublications.org/content/early/2013/01/23/peds.2012-3543.abstract?papetoc

“It is critical that physicians are aware of the HIV transmission risk from human milk and the current recommendations for feeding HIV-exposed infants in the United States. Because the only intervention to completely prevent HIV transmission via human milk is not to breastfeed, in the United States, where clean water and affordable replacement feeding are available, the American Academy of Pediatrics recommends that HIV-infected mothers not breastfeed their infants, regardless of maternal viral load and antiretroviral therapy.”

Thanks to Mike Hart for sharing this link.

False-positive serology for Celiac disease

It is prudent to exercise caution in establishing a diagnosis of Celiac disease (CD) in young asymptomatic children who are identified with screening serology (J Pediatr 2012; 161: 980-14).

In this Italian study, a nationwide, multicenter, prospective intervention trial was established to assess the role of age at gluten introduction on development of CD.  Subjects were recruited at birth who were at increased risk for CD; they had at least one first-degree relative with CD.

In their cohort, 96 children were identified.  In addition to having an affected first-degree relative, all children had positive serology (21 with positive tissue transglutaminase IgA antibody [tTG] and 1 with IgA deficiency/positive gliadin IgG antibody) and results of a small intestinal antibody.

While 72 had definitive CD, 24 were considered potential CD (serology positive/Marsh 0-1 histology) and asymptomatic.  The fascinating part of this study was the followup of the potential CD cases –21/24 continued on a regular diet.  Only 1 developed overt CD. 18 (86%) developed normal serology and 2/21 had fluctuating antibody levels after two years.

Based on their findings as well as consensus guidelines, the authors propose that asymptomatic young patients with abnormal serology should be followed for at least 3-6 months as long as tTG < 11 times ULN.

Other findings:

  1. Breastfeeding may have a protective role; individuals with overt CD had a shorter mean duration of breastfeeding than the potential CD group (4.2 months compared with 5.1 months).
  2. Gluten introduction at age 6 months did not increase risk of overt CD (compared to potential CD) relative to introduction at 12 months.

Related blog entries:

Long-chain polyunsaturated fatty acids, breastmilk, and infant cognition

A lot has been written about improving infant cognition and breastfeeding, even on this blog (More evidence that breastfeeding improves cognitive development).  Formula companies in their efforts to duplicate the nutritional value of breast milk have supplemented with a number of agents, including long-chain polyunsaturated fatty acids (LCPUFA).  But, does this work?

A meta-analysis of LCPUFA supplementation failed to show any significant effect on early infant cognition (Pediatrics 2012; 129: 1141-49).  Twelve trials with 1802 infants met inclusion criteria.  Included trials were randomized clinical studies that measured cognition with Bayley Scales of Infant Development.

LCPUFAs have been hypothesized to be a potential reason for improved cognition.  LCPUFAs are vital for cell membranes and play a critical role in development and growth.  The two main LCPUFAs are docosahexaenoic acid (DHA) and arachidonic acid (AHA). “An estimated 30-fold increase in the amount of DHA and AA in the infant forebrain occurs between the last trimester of pregnancy and the first 2 years of life.”

The authors note that while breastfed babies tend to have higher intelligence, confounding factors have made it difficult to determine whether actual nutritional differences in breast milk are the reason for this difference.  On average, breastfeeding mothers have higher intelligence, larger incomes, and spend more time with their infants.  Thus, bonding/social interactions as well as other breast milk properties (eg antimicrobial, antiinflammatory, and immunomodulatory) may be important factors.

On the same subject, a second article in the same issue (Pediatrics 2012; 129: 1134-40) also showed that breastfed infants had slightly improved cognitive development compared with formula-fed babies (both cow’s milk and soy formula).  This conclusion was based on Bayley Scales of Infant Development and the Preschool Language Scale-3.  In total, this study examined 391 infants at ages 3, 6, 9, and 12 months.  The authors state that “models were used while adjusting for socioeconomic status, mother’s age and IQ, gestational age, gender, birth weight, head circumference, race, age, and diet history”  –that’s a lot of variables to adjust!

More on breast milk from previous blog entries:

Breastfed babies less likely to develop fatty liver

Breastfeeding: protection from asthma

Breastfeeding: protection from asthma

Good news for breastfed babies –breastfeeding may reduce risk of wheezing and asthma for several years (J Pediatr 2012; 160: 991-6).

In this prospective birth cohort study of 1105 infants from New Zealand, detailed feeding information was obtained at 3, 6, and 15 months which allowed calculation of breastfeeding duration. This information was correlated with information about wheezing and asthma collected at 2, 3, 4, 5, and 6 years.

Findings (after controlling for confounding variables):

  • Each month of exclusive breastfeeding was associated with significant reductions in asthma at all timepoints.  The effect was most prominent at younger ages.
  • The authors estimate that if every infant in the cohort had been exclusively breastfed for 6 months, that asthma would have been reduced by 50% at 2 years, 42% at 3 years, 30% at 4 years, 42% at 5 years, and 32% at 6 years.
  • In atopic children, the effects of exclusive breastfeeding are more pronounced.  In this study, exclusive breastfeeding for ≥3 months reduced asthma at ages 4, 5, and 6 by 62%, 55%, and 59% respectively.

The authors note that not all studies have found that breastfeeding improves asthma.  However, most of these studies reported outcomes in older children.

Related Posts:

Breastfed babies less likely to develop fatty liver

More evidence that breastfeeding improves cognitive development

Additional references:

  • -NEJM 2011; 364: 701, 769.  Living on a farm decreases risk of childhood asthma.
  • -Thorax 2009; 64: 604-9. Breastfeeding and asthma in children followed for 8 years.
  • -Br Med J 2007; 335: 815-20.  Longer time of breastfeeding does not reduce allergy/asthma. n=17,046 pairs of mother-infant (13,889 followed up at age 6.5yrs)

Breastfed babies less likely to develop fatty liver

In a study presented at AASLD meeting (San Francisco, November 4, 2011), Ayonrinde et al followed 1170 children in Australia (www.rainstudy.org.au) from birth to age 17. Anthropometric measurements were followed regularly and a liver ultrasound was obtained at age 17.  Patients who reported consuming alcohol were excluded.

By age 17, 16% of girls and 10% of boys had developed nonalcoholic fatty liver disease (NAFLD). Breastfeeding was highly protective.  Infants breastfed for more than 6 months were less than half as likely to develop NAFLD.

As noted in this blog recently (A liver disease tsunami), fatty liver disease is a huge problem.  While this study may not influence the choice to breastfeed in many cases, it highlights yet another advantage of breastfeeding. 

Previous post on breastfeeding:

More evidence that breastfeeding improves cognitive development

More evidence that breastfeeding improves cognitive development

A large cohort study from the United Kingdom with 11,101 term infants and 778 preterm infants shows improved cognitive development when infants are breastfed.  J Pediatr 2012; 160: 25-32.  There have been a number of previous studies as well that have shown that breastfed children have an IQ that is ~5 points higher than nonbreastfed children; however, when adjustment for confounders, especially maternal education, this effect is weaker.  Since this is an observation study (randomized blinded study would be impossible), it is difficult to control for all variables.  Nevertheless, prolonged breastfeeding, more than 2 months in preterm and more than 4 months in term infants, is associated with higher cognitive development.

Additional references:

  • Am J Clin Nutr 199; 70: 525-35.
  • BMJ 2006;  333: 945.
  • Arch Gen Psychiatry 2008; 65: 578-84.
  • Paediatr Perinat Epidemiol 2003; 17: 81-90.

Other refences:

  • J Pediatr 2009; 155: 421.  Breastfeeding may have possible protective effect from developing inflammatory bowel disease.  Review of multiple studies.
  • J Pediatr 2002; 141: 764.  Breastfeeding may protect against obesity.
  • BMJ 2007; 335: 815-20.  Longer time of breastfeeding does not reduce allergy/asthma. n=17,046 pairs of mother-infant (13,889 followed up at age 6.5yrs)