As a new parent you can go no longer than 24 hours without hearing the phrase “Breast is Best.” I know this to be true because I became a parent in June of this year. In the hospital we were offered consults with lactation and had no less than six posters in our room touting the benefits of breastfeeding. As a PhD student I was intrigued by the literature behind these recommendations and eagerly spent multiple late night nursing sessions on my iPad reading the latest research. What I found were some studies finding associations with reduced risk of obesity, and others failing to find this same association (literature). Overall, it was concluded in the previous review that breastfeeding was associated with a reduced risk of obesity.

While this was great news, I could not help but question; was this association because of breastmilk or mode of delivery? Bottle feeding is typically associated with formula feeding but a growing number of women have begun pumping their breastmilk after returning to work or in cases of pre-term birth and latch issues.

Could bottle feeding breastmilk still ameliorate the risk of obesity later in life?

I was not the first person to raise this question which has been addressed here, here, here, and here. Overall the consensus seems to be that early bottle feeding, of breastmilk or formula, is associated with an increased risk for excess weight gain and poor self regulation. Exclusively feeding expressed milk is also associated with early cessation of breast-milk feeding.

So this leads to the inevitable question; what is a mother to do?

While the literature is still unclear if bottled breastmilk can fight obesity risk, it is clear the breastmilk has multiple other benefits according to the American Academy of Pediatrics and should be offered when possible. So to those mothers who pump a little, a lot, or all the time, I say pump on ladies!

For many generations parenting books and gurus alike have heralded the importance of routine. Beginning in infancy, children are scheduled to eat, sleep and play, and busy moms often follow this schedule to assure their youngest children are happy, healthy and well socialized. But, as is always the case, children grow older and become involved in more activities making it difficult to stick with rigid schedules established in infancy.

Recent evidence however has shown that regular mealtimes, bedtimes and limits on television at age 3 were all linked to children having better emotional self-regulation later in life. Self-regulation has two distinct domains, emotional and cognitive. Together, these domains help children control their attention. While these two domains have traditionally been studied together it is important to examine them independently as emotional self-regulation is tied to subcortical structures in the brain while cognitive self-regulation is based in the prefrontal cortex. The prefrontal cortex is known to mature later in development continuing its maturity until the early 20’s so outcomes based on these two domains must be distinct.

Anderson and colleagues (2017) tackled these questions in their recent publication accepted in the Journal of Obesity. Using a prospective study they examined how both domains of self-regulation and routine can impact obesity later in childhood (although only until age 11). The Millennium Cohort Study gathered data from 19,244 families recruited in the UK from 2000-2002. Data was collected beginning at 9 months with follow-ups at ages 3, 5, 7 and 11. Child Social Behavior Questionnaires were used at age 3 to determine self-regulation, while height/weight was used at age 11 to determine BMI and obesity status. A series of logistic regressions were used to understand how self-regulation and routine related to risk for obesity at age 11.

Results showed that having a “sometimes-regular bedtime” or “inconsistent bedtimes” were both associated with elevated risk for obesity at age 11. High television/video viewing time was initially associated with higher obesity rates but the result was not significant after controlling for other routines, a result that could be explained by the imprecise measurements used to quantify time spent. Surprisingly, children with mealtimes that varied considerably were found to be less likely to be obese at age 11. While this study agrees with previous literature in terms of bedtime, the results for mealtime were unexpected and need to be considered in the context of the study which was observational and based on parent self-report. Overall, emotional self-regulation and household routines were independent predictors of obesity at age 11 and those children with regular bedtimes, mealtimes, and limits on television/video displayed enhanced emotional self-regulation.

While this study demonstrates the importance of routine, it is important to understand that many factors could not be controlled for, leaving the study with multiple limitations. Still, if putting the kids to bed at the same time could be protective, maybe those rigid schedules shouldn’t be abandoned just yet.

 

References:

Anderson, S. E., et al. “Self-regulation and household routines at age three and obesity at age eleven: Longitudinal analysis of the UK Millennium cohort study.” International journal of obesity (2005) (2017).

Sowell, Elizabeth R., et al. “Mapping cortical change across the human life span.” Nature neuroscience 6.3 (2003): 309-315.

 

Does Breastfeeding Make You Smarter?

Good nutrition has been shown to help with survival, growth, mental development, health, and well-being across one’s lifespan. Unearthing precisely what to eat to help achieve maximal benefit has been the subject of many research studies and debates, especially regarding childhood nutrition starting at an early age.

Breastfeeding has been recognized for its ability to provide infants with essential nutrients to help with growth and development. Research has shown there are many benefits associated with breastfeeding, such as building a healthy gut microbiota and increasing the bond between mother and child. The child benefits from the nutrients found in breast milk, such as docosahexaenoic acid (DHA) and arachidonic acid, omega-3 and -6 fatty acids essential for cognitive development. Somewhere down the line the notion that breastfeeding can make your baby smarter has been perpetuated. However, this has not yet been proven.

Researchers from the University College Dublin in Ireland conducted a study to investigate the impact of breastfeeding on children’s cognitive development. Around 8,000 families from the Growing Up in Ireland longitudinal infant cohort were randomly selected to participate. Data was collected when the child was 9 months old, 3 years old, and 5 years old. Questionnaires were used to measure children’s cognitive abilities, expressive vocabulary, and problem behaviors, and breastfeeding data was collected as retrospective self-report from the mothers. Propensity score matching, instrument variables, and sibling pair models were used for the analysis. The “breastfed” and “never breastfed” groups were matched based on infant, mother, and family-level factors, such as birth weight and maternal age.

Children who were breastfed scored higher on the problem-solving scale. However, after adjusting for potential confounders, this result was found to be no longer significant. This means other factors, such as socioeconomic status, could better explain the variability here. Breastfed children had lower parent-rated hyperactivity compared with controls after the adjustment, but this effect was only seen at 3 years of age. This may mean that breastfeeding helps reduce hyperactivity in the short term, but this effect was not maintained. Although the researchers found no evidence to support that breastfeeding helps improve cognitive abilities, they did note that their study did not contradict any of the medical benefits of breastfeeding. Research on breastfeeding will continue to be done and hopefully we will see more positive findings emerge in this area. For now, the current World Health Organization recommendation for breastfeeding is to exclusively breastfeed for the first 6 months of a child’s life, if you are able.

 

References:

Girard L, Doyle O, Tremblay RE. Breastfeeding, Cognitive and Noncognitive Development in Early Childhood: A Population Study. Pediatrics. 2017;139(4):e20161848. doi:10.1542/peds.2016-1848

Student Blogger for Global Nutrition Council at ASN’s Scientific Sessions and Annual Meeting at EB 2016

By: Sheela Sinharoy, MPH

A symposium called Biology of Linear Growth on Tuesday examined linear growth from the molecular to the population level, bringing perspectives from biology, physical anthropology, nutrition, and epidemiology

Are you familiar with the process of endochondral ossification? Julian Lui, MD PhD explained that this is the process that results in linear growth. It takes place in the growth plates, at the end of long bones such as the femur, and is subject to systemic regulation by endocrine, nutritional, and inflammatory cytokine factors as well as local regulation by paracrine factors and other cellular mechanisms. Malnourished children have lower levels of hormones like insulin-like growth factor 1 (IGF-1) and estrogen, as well as increased levels of glucocorticoids, leading to decreased linear growth. Dr. Liu explained that this allows the body to conserve resources and that, in situations of food insecurity, “Growth is something of a luxury that can be postponed until better times.”

Rather than growing continuously, children grow in saltations, meaning that – as many a parent has observed – a child may grow substantially overnight and then not at all for a number of days afterwards. Michelle Lampl, MD PhD stated that as children age, these saltations become less and less frequent, with older children growing much less often than infants. The amount and frequency of these growth saltations can be affected by environmental factors, which can interact with cellular effects. Maternal smoking, for example, has a well-documented inhibitory effect on growth, as does maternal alcohol consumption and stress.

Since linear growth happens most rapidly in early life, the first 1,000 days from conception to two years of age are considered a critical period. Parul Christian, DrPH presented results from a meta-analysis analyzing various maternal and child nutrition interventions targeting this 1,000-day window. Starting during pregnancy, balanced protein-energy, iron-folic acid, and multiple micronutrient supplementation were all found to increase birth weight. However, maternal supplementation during pregnancy was not associated with any long-term linear growth in children under five years old. For infants and young children, nutrition promotion and food supplementation showed promise as interventions with positive impacts on child height.

In the final talk of the symposium, Aryeh Stein, PhD addressed the question of linear catch-up growth: for those children whose growth has been suppressed by malnutrition, is it possible to catch up on missed growth, even after the first 1,000 days? A number of studies have provided different nutrients and foods to children ages two and older. Dr. Stein presented results from studies of protein, zinc, iron, iodine, calcium, multiple micronutrients, and food. Protein and some of the micronutrients may have promise, but several of the calcium studies reported negative effects, while food had no association with growth.

The symposium made it clear that nutrition has an important role to play in stimulating or inhibiting linear growth. However, a great deal remains to be learned about these complex biological processes and the most effective interventions to promote children’s optimal growth.

Student Blogger for Global Nutrition Council at ASN’s Scientific Sessions and Annual Meeting at EB 2016

By: Sheela Sinharoy, MPH

A symposium titled Program Effectiveness for Addressing Undernutrition during the First 1,000 Days provided attendees with examples of programs in Bangladesh, Guatemala, and Burundi.

In Bangladesh, the Rang-Din Nutrition Study tested lipid-based nutrient supplements (LNS) in a community-based program. According to presenter Kay Dewey, the study found that giving LNS to mothers prenatally reduced the prevalence of stunting and increased the birth weight, head circumference, and body mass index (BMI) in infants at birth. LNS and multiple micronutrient powders (MNP) for children were also associated with better developmental and cognitive outcomes. Dr. Dewey noted that the impact on child anthropometry was much larger in food insecure households, so future programs may want to target based on this and other criteria.

Moving from Asia to Africa, Marie Ruel presented results from an impact evaluation of a food-assisted integrated health and nutrition program in Burundi. The program gave food rations to mothers and children and also provided behavior change communication. Interestingly, the nutrition situation in Burundi deteriorated sharply during the program period, but decreases were less severe in the treatment groups. For example, while the prevalence of stunting increased dramatically in the control group, the prevalence in the treatment group remained essentially flat. Thus, although the treatment group did not improve, the results suggest that the intervention protected families who otherwise would have been vulnerable to economic shocks.

Guatemala is another country with a very high prevalence of chronic undernutrition, and Deanna Olney presented results from a study of a similar food assistance program. The impact of the program was greatest among those who received a full family food ration plus an individual ration of corn-soy blend. In these households, mothers had significantly higher mean BMIs, children had a lower prevalence of stunting, and both mothers and children had a lower prevalence of anemia. However, there were no significant impacts on child underweight, wasting, or language or motor development.

The differing impacts of various programs was the impetus for a talk by Per Ashorn, who discussed pathways of impact for fetal growth, linear growth, and cognitive function. He explained that the pathways for linear, ponderal, and head growth are partially different, and there are possibly partially different pathways to childhood length gain and brain function. This suggests a need for multipronged interventions targeting pathways including infection, nutrition, and inflammation, as well as a variety of outcome measures to assess the interventions’ impact.

Of course, cost is an important – and often challenging – issue when planning interventions. The final talk of the symposium was given by Steve Vosti, who explained that programs must balance need, acceptability, use, and both short-term and persistent demand in order to achieve impact. These and many other factors, such as the costs of manufacturing supplements in country and the proportion of locally available ingredients being used, can affect the cost of an intervention. In addition to deciding on the most appropriate intervention to meet a need, practitioners must take these factors into account when planning their programs.

By: Sheela Sinharoy, MPH

Sunday began with a symposium titled, Delivering Nutrition Interventions to Women during Pregnancy: Beyond Individual Interventions to Comprehensive Antenatal Guidelines and Care. A series of speakers made clear that as antenatal care (ANC) models continue to evolve, there is plenty of room for improvement to provide a positive pregnancy experience for women and their families.

ANC is not meeting its potential. This was the conclusion of the first speaker, Erica Phillips. She discussed the model of focused ANC (FANC) recommended by the World Health Organization (WHO), which involves 75-80 tasks for an intake visit and 60-65 tasks for each follow-up. She explained that following these recommendations would require an estimated 30-40 minutes for a first visit and 20 minutes for a follow-up. Even when recommended tasks are completed, quality of care may still be low. Ms. Phillips stated that “where FANC has been adopted, success has been limited.”

Still, ANC can be an effective platform for breastfeeding promotion, according to the next speaker, Mduduzi Mbuya. He presented a case study from the Sanitation, Hygiene, Infant Nutrition Efficacy (SHINE) trial in Zimbabwe. The country faces a critical shortage of health workers, with only 9.8 skilled health workers per 10,000 people (as compared to a ratio of 117:10,000 in the USA). SHINE therefore engaged community-based village health workers and found that the prevalence of exclusive breastfeeding at six months of age increased from 23% to 68%. Dr. Mbuya attributed this result primarily to strong fidelity of implementation by village health workers.

Micronutrient supplementation is another important component of ANC, and Kate Dickin spoke about a trial of calcium supplementation in Kenya and Ethiopia. There, researchers found that women were motivated and willing to take calcium supplements as recommended and that most women sustained their adherence to the supplements through the six-week study period and said they would continue through the end of their pregnancies. Dr. Dickin attributed this largely to the intervention’s behavior change communication strategy, which was based on extensive formative research and addressed context-specific motivators and barriers.

Next, Catharine Taylor spoke about the way forward and the need for integrated, women-centered models of care. She said that ANC models should take the local context into account; have all goods and personnel in same physical space; provide clear and consistent guidelines, training and supervision to health workers; provide demonstrations and encourage active engagement and discussion; provide incentives and support; and implement women-held records and integrated health registers. As examples, she described the Centering Pregnancy model and women’s support groups, which have shown promise in a number of developing country settings.

Finally, Rebecca Stoltzfus closed the session, emphasizing the need for more community-based evidence, especially looking at “packages of ANC that are contextually adapted to be delivered in the most effective ways.” Thus, symposium attendees walked away with a substantial research agenda for the strengthening of antenatal guidelines and care.

 

By: Mary Scourboutakos

Neural tube defects are a type of birth defect—affecting the brain, spine or spinal cord—that result from suboptimal folate status.
Folate is a B vitamin that’s naturally found in legumes (like chickpeas, lentils, pinto and kidney beans), seeds, leafy greens (like spinach, collard greens and romaine lettuce) and other vegetables such as asparagus, brussels sprouts and broccoli.

The problem is, people don’t eat enough of these foods. As a result, for many years, pregnant women were at risk for folate deficiency and hence, neural tube defects.

Prenatal supplements were the original solution to this problem as one of their prime ingredients is folic acid, the synthetic form of folate. However, they’re not a fool proof solution because neural tube defects form within four weeks of conception, often before women know they’re pregnant, and thus, before they start taking their supplements.

As a result, in the late 1990s folic acid was mandatorily added to white flour and enriched grain products to ensure that pregnant women would get enough folate, irrespective of whether they take a supplement.

Problem solved? Sort of…

Back in the early 1990s when discussions regarding the addition of folic acid to the food supply were taking place, it was suggested that after fortification was implemented, the dose of folic acid in prenatal supplements should be revised to prevent excessive intakes. The new problem is…the doses were never revised.

Currently, marketed prenatal supplements usually contain 1000 micrograms of folic acid, which is the daily upper limit for folic acid. Meanwhile, it’s recommended that pregnant women should consume about 400 micrograms of folic acid per day for neural tube defect prevention.

With mandatory fortification, three-quarters of a cup of cereal can provide greater than 400 micrograms of folic acid. So if you add a prenatal supplement to a bowl of cereal at breakfast, some bread at lunch, and pasta for dinner, you’re consuming a lot of folic acid!

According to Dr. Deborah O’Connor, a Professor from the University of Toronto who has spent decades studying folate and infant health, this could be a problem. She explained that in animal models, it has been shown that folate can make changes to the genes that are transcribed during development. And while similar data have not been done on humans, she said “if you’re not getting any benefit from those high levels, it would be prudent to cut back given the current status…(because) if there’s no benefit, there’s only a risk.”

From a regulatory point-of-view, she says there’s nothing stopping the industry from changing the amount of folic acid in the supplements. She suggested that the industry’s reluctance to modify the dose in prenatal supplements is probably due to inertia and the fact that “with nutrition you’re always fighting against the more is better philosophy.”

In the meantime, what should women do? In their 2015 clinical practice guidelines, the Society of Obstetrics and Gynecologists recommended a multivitamin containing 400 to 1000 micrograms of folic acid. But currently, there are no prenatal vitamins available with less than 1000. Hence, Dr. O’Connor’s recommendation is “do not use the prenatal, just use a regular multi-vitamin and maybe add a little iron.” Furthermore, she added “care must be taken to ensure vitamin A intakes do not exceed 3,000 mcg retinol activity equivalents (RAE) or 10,000 IU during pregnancy.”

Alas, it’s a classic story, you try to fix one problem, but in doing so, you create another. Hopefully prenatal supplements will be adjusted soon, but in the meantime, prudent folic acid intakes are probably a good idea.

By: Mary Scourboutakos

Presently in America breastfeeding rates are sub-par.

While the World Health Organization recommends exclusive breastfeeding for up to six months of age, with continued breastfeeding alongside complementary foods up to two years of age or beyond—in the US 79% of mothers initiate breastfeeding, but only 22% exclusively breastfeed to six months and only 27% are still breastfeeding (non-exclusively) at two years postpartum.1 Meanwhile in countries like Sri Lanka, 83.1% of mothers are still breastfeeding their children two years post-partum.2

So the question is…how do we get women in America to breastfeed longer?
Traditionally, when trying to promote breastfeeding, people have focused on the benefits for infants, such as improved cognitive development,3 fewer childhood infections,4 and decreased risk for obesity and chronic disease later in life.5

But when you consider current rates of breastfeeding (see above!), clearly this approach isn’t working. Nevertheless, there may be a presently unexplored way to promote breastfeeding…

Emerging research suggests that in fact, the benefits of breastfeeding for the mother may surpass the benefits of breastfeeding for the infant.6-8
In fact, research has shown that long-term breastfeeding is associated with decreased maternal risk for breast cancer,9-11 ovarian cancer,12, 13 endometrial cancer,14 diabetes,15 heart disease,16 as well as greater postpartum weight-loss,17, 18 and mental health benefits.19, 20

But how long is long? And by how much does risk decrease? In terms of breast cancer, research from China has shown that women who breastfeed for more than 24 months per child cut their risk for breast cancer in half, compared to women who breastfed for only one to six months.10 Furthermore, dose-response curves for risk of diabetes show an inverse relationship with lifetime duration of breastfeeding, which suggests that the longer you breastfeed for, the lower your risk is.15

So, my unsolicited piece of advice for public health agencies is…if you’re trying to improve rates of breastfeeding, never mind touting the benefits for the baby, maybe try promoting the benefits for the Mom!

REFERENCES

1.National Center for Chronic Disease Prevention and Health Promotion. Breastfeeding – Report Card. 2014; Available at:http://www.cdc.gov/breastfeeding/pdf/2014breastfeedingreportcard.pdf(Accessed: 7 February 2016).
2.Ministry of Health Care and Nutrition. Sri Lanka – Demographic and Health Survey. 2006; Available at: http://www.statistics.gov.lk/social/DHS%20200607%20FinalReport.pdf (Accessed: 2016 February).
3.Quigley MA, Hockley C, Carson C, Kelly Y, Renfrew MJ, and Sacker A. Breastfeeding is associated with improved child cognitive development: a population-based cohort study. J Pediatr, 2012. 160(1):25-32.
4.Li R, Dee D, Li CM, Hoffman HJ, and Grummer-Strawn LM. Breastfeeding and risk of infections at 6 years. Pediatrics, 2014. 134 Suppl 1:S13-20.
5.Yan J, Liu L, Zhu Y, Huang G, and Wang PP. The association between breastfeeding and childhood obesity: a meta-analysis. BMC Public Health, 2014. 14:1267.
6.Schwarz EB. Infant feeding in America: enough to break a mother’s heart? Breastfeed Med, 2013. 8(5):454-7.
7.Bartick MC, Stuebe AM, Schwarz EB, Luongo C, Reinhold AG, and Foster EM. Cost analysis of maternal disease associated with suboptimal breastfeeding. Obstet Gynecol, 2013. 122(1):111-9.
8.Bartick M and Reinhold A. The burden of suboptimal breastfeeding in the United States: a pediatric cost analysis. Pediatrics, 2010. 125(5):e1048-56.
9.Zhou Y, Chen J, Li Q, Huang W, Lan H, and Jiang H. Association between breastfeeding and breast cancer risk: evidence from a meta-analysis. Breastfeed Med, 2015. 10(3):175-82.
10.Zheng T, Duan L, Liu Y, Zhang B, Wang Y, Chen Y, et al. Lactation reduces breast cancer risk in Shandong Province, China. Am J Epidemiol, 2000. 152(12):1129-35.
11.De Silva M, Senarath U, Gunatilake M, and Lokuhetty D. Prolonged breastfeeding reduces risk of breast cancer in Sri Lankan women: a case-control study. Cancer Epidemiol, 2010. 34(3):267-73.
12.Luan NN, Wu QJ, Gong TT, Vogtmann E, Wang YL, and Lin B. Breastfeeding and ovarian cancer risk: a meta-analysis of epidemiologic studies. Am J Clin Nutr, 2013. 98(4):1020-31.
13.Li DP, Du C, Zhang ZM, Li GX, Yu ZF, Wang X, et al. Breastfeeding and ovarian cancer risk: a systematic review and meta-analysis of 40 epidemiological studies. Asian Pac J Cancer Prev, 2014. 15(12):4829-37.
14.Jordan SJ, Cushing-Haugen KL, Wicklund KG, Doherty JA, and Rossing MA. Breast-feeding and risk of epithelial ovarian cancer. Cancer Causes Control, 2012. 23(6):919-27.
15.Aune D, Norat T, Romundstad P, and Vatten LJ. Breastfeeding and the maternal risk of type 2 diabetes: a systematic review and dose-response meta-analysis of cohort studies. Nutr Metab Cardiovasc Dis, 2014. 24(2):107-15.
16.Schwarz EB, Ray RM, Stuebe AM, Allison MA, Ness RB, Freiberg MS, et al. Duration of lactation and risk factors for maternal cardiovascular disease. Obstet Gynecol, 2009. 113(5):974-82.
17.Jarlenski MP, Bennett WL, Bleich SN, Barry CL, and Stuart EA. Effects of breastfeeding on postpartum weight loss among U.S. women. Prev Med, 2014. 69:146-50.
18.Baker JL, Gamborg M, Heitmann BL, Lissner L, Sorensen TI, and Rasmussen KM. Breastfeeding reduces postpartum weight retention. Am J Clin Nutr, 2008. 88(6):1543-51.
19.Groer MW. Differences between exclusive breastfeeders, formula-feeders, and controls: a study of stress, mood, and endocrine variables. Biol Res Nurs, 2005. 7(2):106-17.
20.Groer MW and Davis MW. Cytokines, infections, stress, and dysphoric moods in breastfeeders and formula feeders. J Obstet Gynecol Neonatal Nurs, 2006. 35(5):599-607.

By Christopher Radlicz

Currently, only one-quarter of pregnant women in the United States are eating the amount of fish recommended for optimal maternal and child health (1). On the other end of the spectrum, about 10% of women of childbearing age have higher than recommended blood mercury concentrations (2).

A qualitative study done in 2010 has helped explain why women may be consuming less than the recommended two-servings of fish per week (1). Pregnant women in the Boston area, who under-consumed fish according to these guidelines, were broken into focus groups and discussed what was keeping them from eating more fish. These groups revealed that many women knew that fish might contain mercury, but were naïve of the fact that fish contained beneficial fatty acids, such as docosahexaenoic acid (DHA), which is essential for optimal fetal brain development (3). The women admitted that they hadn’t received advice to eat more fish or more specifically to eat fish that contain lower amounts of mercury and higher amounts of beneficial fatty acids. Instead, the women confessed that they were advised to limit fish intake due to possible mercury exposures.

Are these women misguided in keeping their fish consumption below the recommended two-servings per/week during pregnancy?

This past February, The 2015 Dietary Guidelines Advisory Committee reiterated that women who are pregnant, nursing, or are planning to become pregnant should still consume fish because neither the risk of mercury nor other organic pollutants outweigh the benefits (4). In a recent New York Times article on the issue, Dr. Steve Abrams, medical director of the Neonatal Nutrition Program at Baylor College of Medicine and panel member on the advisory committee commented on tuna consumption, explained, “The benefit of having (omega-3 fatty acids) in your diet really exceeds the likely risk of contamination. The point is that you should have a variety of types of seafood and not limit yourself to one type, and variety includes canned tuna.”(5).

The intake of fish during pregnancy is certainly more nuanced than simple elimination from the diet due to potential mercury exposure. Fish contains essential nutrients proven to have beneficial effects on brain neurodevelopment and may prevent cardiovascular disease (6). These benefits have been attributed in part to the long chain polyunsaturated fatty acids (LCPUFAs), DHA and eicosapentaenoic acid (EPA), but in addition seafood is a good source of protein, selenium, iron, iodine, choline, and vitamins E and D (4,7). These LCPUFAs are essential throughout pregnancy but are critical from the beginning of the third trimester until about 18 months after birth when the human brain is growing the fastest. Neglecting to supply LCPUFA among other nutrients during this period may result in deficits in brain development (9).

That being said, mercury exposure is a real possibility. Methylmercury is the organic form of mercury that we are exposed to when consuming fish in our diet. This form of mercury is relatively stable, mobile within the body, and exhibits a high potential to damage the brain (8). Mercury poisoning outbreaks in Japan are a testament to the wide spread damage that can occur from exposure to methylmercury, resulting in infants born with serious neurological damage, even when mothers were seemingly unaffected (10).

Extreme exposure to mercury in the food chain as in the case of Japan is a rather isolated instance though. But what is the balance? Do the beneficial effects of fish counteract the adverse effects of toxicants?

In the literature, detection of methylmercury exposure in infants is typically done by measuring levels in maternal hair, maternal toenails, cord blood, and maternal blood. These methods are variable in measuring biomarkers and on certain occasion, can be imprecise (5,7). Additionally, many observational studies do not statically control for negative confounders. This means that majority of the cohort studies done in this field have focused on either the risk of methylmercury or on nutrient benefits but not both (7).

All of the complications in study design and analysis show the complexity of establishing recommendations from these studies. Even with good study designs, clear-cut recommendations as to how much fish pregnant women should eat may still not be feasible, due to the variability of toxicants in seafood species. Empowering pregnant women by informing them of seafood that is lower in mercury levels and higher in LCPUFAs is a practical solution. A pertinent rule to apply when making seafood choices is that small sea creatures, which live shorter lives and are lower on the food chain, tend to be the lowest in methylmercury levels and exponentially higher in LCPUFAs. Larger seafood, on the other hand, tends to have higher levels of methylmercury due to a longer lifespan and their higher settlement on the food chain allowing for an accumulation of more methylmercury. The Dietary Guidelines Advisory Committee is in consensuses with the FDA and EPA in advising pregnant women to avoid eating these larger fish, such as swordfish, tilefish, shark, and king mackerel due to their high levels of methylmercury (4,7).

References:

1.Bloomingdale A, Guthrie LB, Price S, Wright RO, Platek D, Haines J, Oken E. A qualitative study of fish consumption during pregnancy. Am J Clin Nutr 2010; 92: 1234-40. doi:10.3945/ajcn.2010.30070

2.Mahaffey KR, Clickner RP, Bodurow CC. Blood organic mercury and

dietary mercury intake: National Health and Nutrition Examination

Survey, 1999 and 2000. Environ Health Perspect 2004 ;112:562–70.

3.Koletzko B, Cetin I, Thomas Brenna J. Dietary fat intakes for pregnant

and lactating women. Br J Nutr 2007;98:873–7.

4.United States Department of Agriculture. Scientific Report of the 2015 Dietary guidelines Advisory Committee. Washington, DC. 2015.

5.Parker-Pope T. (2015, March 2). Should Pregnant Women Eat More Tuna. The New York Times. Retrieved from http://www.nytimes.com. http://well.blogs.nytimes.com/2015/03/02/should-pregnant-women-eat-more-tuna/?r=0

6.Anon. The Madison Declaration on Mercury Pollution. Ambio 2007;36:62–65. [PubMed: 17408191]

7.Choi AL, Cordier S, Weihe P, Grandjean G. Negative Confounding in the Evaluation of Toxicity: The Case of Methylmercury in Fish and Seafood. Crit Rev Roxicol. 2008; 38: 877-893. doi:10.1080/10408440802273164.

8.Clarkson CW, Vyas JB, Ballatori N. Mechanisms of Mercury Disposition in the Body. American Journal of Industrial Medicine 2007;50:757-764.

9.Innis SM. Essential fatty acids in growth and development. Prog Lip Res 1991; 30: 39.

10.Harada M. Minamata Disease: Methylmercury Poisoning in Japan Caused by Environmental Pollution. Crit Rev Toxicol 1995;25:1–24.

11.Hibbeln JR, Davis JM, Steer C, Emmett P, Rogers I, Williams C, Golding J. Maternal seafood consumption in pregnancy and neurodevelopmental outcomes in childhood (ALSPAC study): an observational cohort study. Lancet 2007;369:578–585.

By Marion Roche, PhD

Approximately 162 million children are stunted.In the global nutrition community the human costs of stunting are well recognized: stunted children complete less school, have less learning and earning opportunities, and females who become moms in the future are more likely to give birth to stunted children. Intervening early in 1000-day window (from conception to the age of two) and even earlier, pre-pregnancy, is recognized as most cost-effective way to prevent, as in many settings it challenging to reverse the physical and cognitive deficits from chronic malnutrition. Beyond the human costs, there is also an economic case to be made for investing in stunting reduction.

Every four years, the world’s leading economists and experts from diverse development fields come together to rank the best investments for development in what is called the Copenhagen Consensus. Nutrition is one such investment that is consistently ranked as a “best buy”. Specific interventions such as vitamin A supplementation, salt iodization, zinc & ORS for diarrhea treatment and support for breastfeeding and adequate complementary feeding have all been in the top 10 best investments in previous years. In addition, nutrition-sensitive approaches, such as keeping girls in school, improvements to agriculture yields and crop quality, enabling gender equity for women, and overall poverty reduction, are all necessary to sustainable long-term stunting reductions for communities and countries.

This month, world leaders and experts met in Addis Ababa, Ethiopia for the Third International Financing for Development conference. A presentation by Dr. Meera Shekar of the World Bank and Dr. Robert Hetch of Results for Development at an MI co-hosted side-event on nutrition at the conference laid out what it would take to achieve the World Health Assembly target of reducing stunting by 40% by 2025. They emphasized that strategic investing in improving the nutrition situation for 68 million children would offer a long-term $45 dollar return on each dollar invested. More specifically, every dollar invested in reducing stunting is estimated to generate an $18 return in the long run. However, although many nutrition interventions look affordable on an individual scale, a more detailed analysis has been done to show what it would cost to deliver these interventions and reduce stunting at a global scale.

The Financing for Development conference was centred on funding the Sustainable Development Goals, the set of targets relating to the of future international development post-2015. Looking at the return on investment (ROI) in nutrition and knowing that nutrition has such a profound effect on other areas of a person’s life, I think there is no better investment the world can make to reach the SDGs more quickly and effectively than that in nutrition!