Long-chain PUFA supplementation in rural African infants: A randomized controlled trial of effects on gut integrity, growth, and cognitive development

Article (PDF Available)inAmerican Journal of Clinical Nutrition 97(1) · December 2012with16 Reads
DOI: 10.3945/ajcn.112.042267 · Source: PubMed
Background: Intestinal damage and malabsorption caused by chronic environmental enteropathy are associated with growth faltering seen in infants in less-developed countries. Evidence has suggested that supplementary omega-3 (n−3) long-chain PUFAs (LC-PUFAs) might ameliorate this damage by reducing gastrointestinal inflammation. LC-PUFA supplementation may also benefit cognitive development. Objective: We tested whether early n−3 LC-PUFA supplementation improves infant intestinal integrity, growth, and cognitive function. Design: A randomized, double-blind, controlled trial [200 mg DHA and 300 mg EPA or 2 mL olive oil/d for 6 mo] was conducted in a population of 172 rural Gambian infants aged 3–9 mo. The primary endpoints were anthropometric measures and gut integrity [assessed by using urinary lactulose:mannitol ratios (LMRs)]. Plasma fatty acid status, intestinal mucosal inflammation (fecal calprotectin), daily morbidity, and cognitive development (2-step means-end test and an attention assessment) were secondary endpoints. Results: PUFA supplementation resulted in a significant increase in plasma n−3 LC-PUFA concentrations (P < 0.001 for both DHA and EPA) and midupper arm circumference (MUAC) (effect size: 0.31 z scores; 95% CI: 0.06, 0.56; P = 0.017) at 9 mo of age. At 12 mo, MUAC remained greater in the intervention group, and we observed significant increases in skinfold thicknesses (P ≤ 0.022 for all). No other significant differences between treatment groups were detected for growth or LMRs at 9 mo or for secondary outcomes. Conclusions: Fish-oil supplementation successfully increased plasma n−3 fatty acid status. However, in young, breastfed Gambian infants, the intervention failed to improve linear growth, intestinal integrity, morbidity, or selected measures of cognitive development. The trial was registered at www.isrctn.org as ISRCTN66645725.



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Available from: Saikou Drammeh, Apr 08, 2016
Long-chain PUFA supplementation in rural African infants:
a randomized controlled trial of effects on gut integrity, growth, and
cognitive development
F van der Merwe, Sophie E Moore, Anthony J Fulford, Katherine E Halliday, Saikou Drammeh, Stephen Young,
and Andrew M Prentice
Background: Intestinal damage and malabsorption caused by
chronic environmental enteropathy are associated with growth fal-
tering seen in infants in less-developed countries. Evidence has
suggested that supplementary omega-3 (n23) long-chain PUFAs
(LC-PUFAs) might ameliorate this damage by reducing gastrointes-
tinal inflammation. LC-PUFA supplementation may also benefit
cognitive development.
Objective: We tested whether early n23 LC-PUFA supplementation
improves infant intestinal integrity, growth, and cognitive function.
Design: A randomized, double-blind, controlled trial [200 mg DHA
and 300 mg EPA or 2 mL olive oil/d for 6 mo] was conducted in
a population of 172 rural Gambian infants aged 3–9 mo. The primary
endpoints were anthropometric measures and gut integrity [assessed
by using urinary lactulose:mannitol ratios (LMRs)]. Plasma fatty
acid status, intestinal mucosal inflammation (fecal calprotectin),
daily morbidity, and cognitive development (2-step means-end test
and an attention assessment) were secondary endpoints.
Results: PUFA supplementation resulted in a significant increase in
plasma n23 LC-PUFA concentrations (P , 0.001 for both DHA
and EPA) and midupper arm circumference (MUAC) (effect size:
0.31 z scores; 95% CI: 0.06, 0.56; P = 0.017) at 9 mo of age. At 12
mo, MUAC remained greater in the intervention group, and we
observed significant increases in s kinfold thicknesses (P # 0.022
for a ll). No other significant differences between treatment
groups were detected for growth or LMRs at 9 mo or for second-
ary outcomes.
Conclusions: Fish-oil supplementation successfully increased plasma
n23 fatty acid status. However, in young, breastfed Gambian infants,
the intervention failed to improve linear growth, intestinal integrity,
morbidity, or selected measures of cognitive dev elopment. The trial
was reg istered at www .isrctn.or g as ISRCTN66645725. Am J
Clin Nutr 2013;97:45–57.
Chronic environmental enteropathy, which is characterized by
intestinal villous atrophy, crypt hyperplasia, and inflammatory
cell invasion of the lamina propria, affects many children living in
developing countries (1–7). Repeated exposure to a wide variety
of pathogenic organisms and allergens that are due to the in-
gestion of contaminated weaning foods and water are thought to
initiate this persistent inflammation of the gut, which leads to
intestinal damage and malabsorption (7–12). Mucosal injuries
that result from inflammatory responses are slow or resistant to
healing and repair and leave the gut vulnerable to additional
damage (9, 13). This decreased gut integrity, which is shown by
markedly and consistently raised lactulose:mannitol ratios
in the dual-sugar permeability test (3, 4, 11), begins in
Gambian infants at w3 mo of age (when weaning foods are first
introduced) and is associated with the faltering in both height
and weight seen in these rural African children (3, 9). There is
evidence that supplementary n23 long-chain PUFAs (LC-
PUFAs) might reduce or delay this damage by reducing gas-
trointestinal inflammation (14–19), but this has not been tested
in an African population.
Meta-analyses of the effects of n23 PUFA interventions on
growth outcomes have been published for high-income countries
and concluded that there is no substantive evidence of a benefit
(20–23). However, the evidence base in respect to infants living
in low-income countries, where gro wth faltering is of much greater
concern, is exceptionally weak. We could not find any published or
registered trials in low- to middle-income countries that inves-
tigated the effects of LC-PUFA supplementation in infants on
growth or immune modulation.
We performed a double-blind, randomized, controlled, parallel-
group trial that was designed to test the hypothesis that supple-
mentary n23 LC-PUFAs would reduce intestinal damage caused
by chronic enteropathy and reduce the associated growth faltering
From the Medical Research Council (MRC) International Nutrition
Group (LFvdM, AJF, SEM, and AMP) and Faculty of Infectious and Trop-
ical Diseases (KEH), London School of Hygiene and Tropical Medicine,
London, United Kingdom; the MRC Keneba, Keneba, The Gambia (LFvdM,
AJF, SEM, AMP, and SD); and the MRC Human Nutrition Research, Elsie
Widdowson Laboratory, Cambridge, United Kingdom (SY).
Supported by the UK Medical Research Council (MC-A760-5QX00), the
Overseas Research Students Awards Scheme, and the Ernest Oppenheimer
Memorial Trust. Nordic Naturals kindly donated all supplement and control
Address reprint requests and correspondence to AM Prentice, Medical
Research Council International Nutrition Group, London School of Hygiene
and Tropical Medicine, Keppel Street, London WC1E 7HT, United King-
dom. E-mail: andrew.prentice@lshtm.ac.uk.
Abbreviations used: AA, arachidonic acid; FA, fatty acid; LC-PUFA,
long-chain PUFA; LMR, lactulose:mannitol ratio; MRC, Medical Research
Council; MUAC, midupper arm circumference.
Receive d May 5, 2012. Accepted for publication October 11, 2012.
First published online December 5, 2012; doi: 10.3945/ajcn.112.042267.
Am J Clin Nutr 2013;97:45–57. Printed in USA. Ó 2013 American Society for Nutrition 45
in 3–9-mo-old Gambian infants living in the rural area of West
Kiang. Supplementation was started at 3 mo of age in an attempt
to prime the intestinal mucosa and delay or prevent the initiation
of events that lead to gut damage.
One of the consequences of increased gut permeability is the
translocation of antigenic macromolecules, which stimulate and
perpetuate local and systemic inflammatory responses (9). To test
whether n23 LC-PUFA supplementation is associated with
reduced infant systemic infla mmation (either via immune-
modulation or by reducing gut leakiness), concentrations of acute-
phase proteins plasma C-reactive protein, a-1-glycoprotein , and
albumin were also assessed. In addition, stool calprotectin was
measured as a marker of intestinal inflammation. General mor-
bidities experienced by infants (eg, diarrhea, vomiting, and fever)
were measured to examine treatment effects in terms of clinical
wellness, and these data contributed to safety monitoring.
In addition, the trial allowed investigations into the effect of
n23 LC-PUFA supplementation on developmental outcomes.
Evidence has suggested that cognitive function in children is
affected by nutritional and health status, particularly during the
rapid-growth phase in the first 2 y of life (24–27), and stunting
during infancy has been related to poor cognitive function in late
childhood (28, 29). Gambian infants may suffer developmental
insults in early life, considering the high rates of stunting and
infections they suffer. LC-PUFAs play a central role in the
normal development and functioning of the brain and central
nervous system, and associations between infant DHA status
and neurodevelopmental outcomes have been shown in several
studies (30–36). Infant LC-PUFA–supplementation studies have
shown mixed results in high-income countries (37), but to our
knowledge, such research in a low-income country setting such
as rural Gambia is lacking.
The study was carried out in the West Kiang region of The
Gambia from May 2007 to October 2008. The Gambian climate
is tropical with 2 main seasons that consist of a hot, rainy season
(June to October) and a cooler, dry season (November to May).
West Kiang is 145 km inland from the capital and spans an area of
80 km
. Keneba is the largest village in this rural area, where
subsistence farming (primarily rice and groundnuts) predominates.
A combination of in utero growth retardation, poor-quality and
frequently contaminated weaning foods, and high levels of in-
fection cause moderately severe growth faltering in almost all
children with an onset at w3 mo postpartum. All infants aged 3
mo who were living in the 16 largest villages of West Kiang and
not enrolled in any other study were eligible to take part in the
current study. In total, 220 infants were assessed for eligibility, of
whom 183 infants were randomly assigned (Figure 1). Infants
with severe congenital abnormalities that could affect growth and
development, infants from multiple births, and infants with known
HIV infection were ineligible for participation.
Potential subjects were identified from the West Kiang De-
mographic Surveillance System (http://www.ing.mrc.ac.uk/research_
areas/west_kiang_dss.aspx). Subjects were automatically allocated
a study number by the database system on recruitment. Each study
number had previously been randomly assigned to one of 4
treatment codes (4 rather than 2 codes were used to promote
blinding) represented by 4 simple pictures on the supplements so
that infants were allocated to either the n23 LC-PUFA or the
control group in a 1:1 ratio. The trial statistician implemented
a permuted block random assignment (block size = 16), which
ensured a uniform distribution of treatments across the seasons of
birth. After mothers had given their consent, and their infants
had been recruited, a fieldworker issued them with a card printed
with the appropriate picture. Mothers were asked to bring their
picture-coded cards when their infants were brought to be admin-
istered the supplement. Fieldworkers were also giv en a treatment
booklet from which to crosscheck for a ny card swapping. All
infants in the study stayed on the same treatment allocations
throughout the duration of treatment. Participants, staff, and in-
vestigators remained blinded to treatment assignment throughout
the duration of the trial.
Intervention and study procedures
Supplementation started at 3 mo of age and ended at 9 mo
of age when all outcome measurements were made apart from
cognitive function (assessed at 12 mo of age). Field assistants
administered the supplement at a central meeting point in each of
the villages each day. Sterile, graded pastettes were used to
squeeze the oil into the side of the mouth of each infant. Mothers
were asked to breastfeed their infants immediately after the oil had
been given. Field assistants who administered the dose recorded
daily compliance.
The intervention group received 2 mL of highly purified fish
oil, which supplied 200 mg DHA and 300 mg EPA/d. The control
group was given the same volume of olive oil. Both oils were
supplied by Nordic Naturals Inc and contained 1.25% lemon oil
for blinding and 0.5% rosemary extract and d-a-tocopherol as an
antioxidant. On the advice of the trial monitor, the usual to-
copherol concentration of 30 IU/5 mL was reduced to 5 IU/5 mL
as appropriate to this age group. The dosage of 500 mg com-
bined DHA plus EPA/d was designed to achieve a substantial
increase in plasma n23 PUFA to both eliminate any existing
deficiencies and elicit a therapeutic response.
A morbidity questionnaire was administered to mothers or
caretakers on a daily basis to assess diarrhea, vomiting, cough,
fever, and (for safety monitoring) possible abnormal bleeding that
might have been related to clotting interference. If a mother felt
that her infant was in need of medical attention, she was free to
take her infant to the Medical Research Council (MRC) clinic in
Keneba to be seen by a doctor or request a visit by a nurse. If the
infant was seen by a nurse or doctor, the diagnosis and treatment
details were recorded.
To reduce intraindividual variance and estimate the reliability
of outcome variables, primary endpoints were taken in triplicate
(on separate days) at baseline and endpoint visits, and the median
value was used for analyses. Mothers were asked to collect a sample
of their infant’s stool into a pot provided the evening before the y
were due to come to Keneba for the clinic visit and to contin ue the
collection during the clinic visit if no stool was passed the
previous evening. Stools were thoroughly homogenized before
freeze drying to a constant weight. Mothers expressed w5mL
breast milk from each breast before their infants received their
first feed at the clinic and again immediately after they had fed
their infants. The 4 breast-milk samples were pooled by mixing
together 1 mL of each sample, and an aliquot of this pooled
sample was stored at 270
C until analysis. An experienced nurse
drew 2 mL venous blood from infants at baseline and endpoint
into anticoagulant-coated tubes. At this age, it is not possible to
obtain fasted samples. Each month, a basic weaning-food ques-
tionnaire was administered to the mother that asked about which
foods the infant had been weaned onto the previous month.
Primary endpoints
Anthropometric measures at 3 and 9 mo were performed (by
LFvdM). Infant lengths and weights were measured by using
a Harpenden Infantometer length board (Holtain Ltd) and
electronic baby scale (model 336; Seca), to a precision of 0.1 cm
and 0.01 kg, respectively. Left-side triceps, biceps, and sub-
scapular skinfold thicknesses were measured with a skinfold-
thickness caliper (Holtain Tanner/Whitehouse) to 2-mm pre-
cision, and midupper arm circumference (MUAC) was measured
by using a paper measuring tape to a precision of 0.1cm. Head
circumference, as a proxy for brain size, was measured to the
nearest 0.1 cm with a stretch-proof measuring tape (Model
CTM08l Chasmors Ltd) around the maximum circumference of
the head (forehead to occiput). Measures for which reference data
were available were expressed as z scores on the basis of WHO
Growth Reference Data (38, 39). Anthropometric measures were
repeated at 12 mo by a fieldworker.
Intestinal absorptive capacity and permeability were assessed
by using the dual-sugar permeability test (4). Infants were given
a 2 mL/kg body weight dose of sugar solution that contained
400 mg lactulose (Lactulose Solution BP; Sandoz Ltd) and 100 mg
mannitol (Sigma-Aldrich Co) per 2 mL H
O. The recovery of the
monosaccharide mannitol provides a measure of passive intestinal
absorption and is reduced by villous atrophy. Paracellular uptake
of the nondigestible disaccharide lactulose is a marker of
intestinal leakiness. Therefore, intestinal permeability is mea-
sured as the urinary lactulose concentration divided by the uri-
nary mannitol concentration. In addition, the ratio of urinary
lactulose:lactose is measured as an indication of lactase activity.
By measuring the total urine volume passed over 5 h postdose
(Hollister U-bag; Abbot Laboratories), the percentage of re-
coveries of the 2 probes was calculated as a reflection of the
amounts taken up by the passive and paracellular intestinal
routes. Urine samples were stored with 2–3 drops of chlorhex-
idinegluconate (5% wt:vol) as a bacteriostatic agent.
Cognitive development at 12 mo
At 12 mo of age (67 d), infants were brought in to the MRC
Keneba field station for their final follow-up visit, during which
cognitive development was tested by using a 2-step means-end
problem-solving test (Willatts’ Infant Planning Test) (40–42)
and a single-object task attention assessment (toddler attention
assessment) (43). The 12-mo time point for assessments was
determined in a pilot study that evaluated the frequency distri-
bution of test scores in 75 West Kiang infants aged 10–12 mo.
On the morning of the test, mothers were asked to ensure that
their infant had been fed before the 15-min test. For standardi-
zation, the 2-step Infant Planning Test was performed first and
was followed by the single-object task toddler assessment. If an
infant did not respond during the Infant Planning Test, the at-
tention assessment was completed first, and a second attempt at
the planning test was made thereafter. The assessment was com-
pleted in a restricted-access room with few distractions. For both
tests, the mother was asked to sit on a chair with her infant on her
lap facing a table placed in front of her. She was asked not to help,
encourage, or prompt her child by either words or actions and not to
FIGURE 1. Subject flowchart summarized according to Consolidated Standards of Reporting Trials that shows the number of subjects randomly assigned,
lost to follow-up, and analyzed by treatment arm.
encourage the infant’s eye contact when he or she looked up at the
mother. A Gambian fieldworker (SD) carried out all tests. The
tests were lmed and saved for later scoring.
The aim of the Willatts’ 2-step Infant Planning Test is to
present a challenge to an infant and observe whether the infant is
capable of planning and executing a solution. The challenge is to
retrieve a toy, which is either concealed or out of reach. The
infant needs to manipulate an intermediary object (cloth or
cover) to retrieve the goal, and the intentionality which the child
uses to retrieve this goal (toy) is assessed. This problem-solving
test is simple to perform and has proven sensitive to nutritional
interventions in infants (40, 41). It has been successfully used in
high-income countries and also in middle- and low-income
countries (44, 45). The test was performed and scored as de-
scribed by Willatts et al (46). For the first outcome measure, trial
behavior scores were averaged to give a mean total intention
score. Each trial in which there was a score of $1 for all 3
behaviors was considered to be an intentional solution. The
number of trials in which the child showed some sign of in-
tention became the second outcome measure of the total in-
tentional solution score.
By conducting this test at 12 mo of age, it was possible to
combine it with the toddler attention assessment. This test involves
a free-play task, whereby the toddler’s attention to a complex toy
is assessed. Infant habituation, which is a decrease in attention to
a repeatedly presented stimulus, is considered a basic tool for the
assessment of cognition or processing speed in infancy. The test
was performed by using previously described methods and
equipment (43). VirtualDub Mpeg-2, FccHandler software (ver-
sion 1.6.19, SourceForge.net), which allows frame-by-frame
playback viewing, was used for scoring. The 2 outcome mea-
surements were as follows: 1) the mean length of looks at the toy
(or mean look duration = the total looking time divided by the
number of looks at the toy) and 2) the inattention rate (the number
of looks away from the toy per minute).
A graduate student (KEH) who trained in the Willatts Lab-
oratory scored all cognitive tests. Because the scoring of the
Infant Planning Test relies in part on subjective interpretation,
cross-validation was achieved by using a 30% sample of Infant
Planning Tests scored by a second observer (LFvdM) who also
trained in the Willatts Laboratory.
Laboratory methods
Urinary lactulose, mannitol, and lactose concentrations were
measured at MRC Keneba by using a 96-well microplate en-
zymatic assay that was based on previously published methods
(47–50). All samples were measured in duplicate. The average
intraassay percentage CV, which was calculated across all rep-
licates run during sample analysis, was 3.01% (urine samples)
and 3.97% (standards) for the lactulose assay and 1.89%
(samples) and 2.36% (standards) for the mannitol assay. The
repeatability of the LMR within individual subjects at each time
point gave an intraclass correlation coefficient of 0.26 and an
estimated reliability of an individual mean of 0.49.
Plasma and breast-milk samples were flushed with nitrogen to
minimize the oxidation of volatile PUFAs before storage at
C. Samples were later transported to MRC Human Nutrition
Research, Cambridge, United Kingdom. To measure plasma and
breast-milk fatty acid (FA) concentrations, total lipid extracts were
prepared from 200 mL thawed plasma or homogenized breast milk
by using an adaptation of the method of Folch (51), and FA methyl
esters were prepared by using acid-catalyzed esterification. A
BPX70 column [70% cyanopropylpolysilphenylene-siloxane
(SGE)], with polarity designed specifically for FA methyl ester
analysis, was used for gas chromatography separation. Elution
profiles for each sample were obtained, which consisted of 38
peaks. Each of the FA components was quantified against
a calibration range of external standards of known concentration
(ng/mL) by using linear regression.
Plasma C-reactive protein was measured by using a commer-
cial colorimetric immunoassay (DimensionCardioPhase high-
sensitivity C-reactive protein method; Siemens Healthcare
Diagnostics Ltd). a-1-Glycoprotein was measured with an im-
munoturbidimetric specific reaction by using a commercial kit
(Sentinel Diagnostics). The Flex reagent cartridge (Siemens
Healthcare Diagnostics Ltd) was used for the measurement of
plasma albumin.
Fecal calprotectin concentrations were measured at MRC
Keneba by using a commercial ELISA kit (Phical; CALPRO AS).
The kit is used primarily for the determination of disease activity
and monitoring the response to treatment in adult patients with
inflammatory bowel disease and patients with colorectal cancers.
The protocol was adapted for use in this population of infants and
on freeze-dried stool. To enable the comparison with reference
values, results were expressed per kilogram of wet stool.
Data handling and statistical analyses
A central database with specific access entry forms and au-
tomatic range checks was created for the trial. All data were
double entered, and real-time checks were performed to enable
a rapid resolution of queries.
Sample-size calculations were based on growth measurements
of 1621 Gambian children and, subsequently, the first 25%
collected urine samples. The main analysis was an intention-to-
treat analysis. Multiple and negative binomial regression anal-
yses, where appropriate, were used to test the effect of treatment
on all primary and secondary endpoints. All endpoints for which
baseline values were collected were fitted as covariates. In
a subsequent analysis, breast-milk DHA and EPA, sex, season of
birth, age of treatment commencement, and, only for cognitive
development outcomes, the highest level of maternal schooling
were added as extra covariates to the regression models. These
variables were identified as potential variance inflators and/or
effect modifiers. To look at the possibility of dose effects, an
additional analysis that fitted the number of doses of treatment,
with compliance controlled for, in the regression models were
done for all primary and secondary endpoints. Compliance was
measured as the percentage of doses taken compared with the
doses offered during each infant’s supplementation period. With
adjustment for the compliance and number of doses, the effect
of treatment as it was received in each individual case was
measured on the various outcomes. A linear regression model
was used to test the relation between each outcome at endpoint
with the various FAs at 9 mo. We used the statistical package
Stata (version 10; StataCorp LP) throughout. Log transformations
were used to both normalize the distribution and stabilize the
variance of skewed variables. For the main LC-PUFAs, we ana-
lyzed relative percentage and absolute concentration differences
between study groups separately. For other FAs and combina-
tions, we used absolute concentrations. Sex differences between
cognitive development test scores were assessed by using re-
gression analysis. For the assessment of test validity, correla-
tions between scores of a second observer who scored a sample
of the Infant Planning Test and those of the first observer were
examined by using Pearson’s product-moment correlation co-
efficients. Bias-corrected 95% CIs for correlation coefficients
were estimated by using the bootstrap approach. The bias be-
tween markers was tested by using a paired t test.
Ethics, governance, and registration
The trial observed MRC UK Good Clinical Practice guidelines,
the current version of the Declaration of Helsinki, and applicable
local ethical and legal requirements. Ethics approval was obtained
from the London School of Hygiene and Tropical Medicine and the
joint Gambian Government/MRC ethics boards. The Gambian
National Nutrition Agency gave their written approval to carry out
the study, and informed assent was given by the village elders.
Written informed consent was provided by the parents or caretaker
of each child. Independent trial and safety monitors were appointed
to monitor and supervise the progress and safety of the trial
throughout and ensure the study abided by MRC UK Good Clinical
Practice standards. The trial was registered as ISRCTN66645725.
Ninety-four percent of the 180 infants who received treatment
completed the follow-up visit at 9 mo of age so that data sets were
Baseline characteristics of study participants
Characteristics Fish-oil group Control group Differences
Male sex [n (%)] 49 (56) 50 (59) 23
Age (d)
92.3 6 4.25
93.2 6 4.22 20.10
Highest level of education of mothers (n)68 68
Arabic school (n)
0–2 y 26 19 7
3–6 y 28 26 2
7–11 y 4 4 0
English school (n)
1–4 y 4 9 25
5–9 y 6 10 24
Anthropometric indexes (n)8785
Weight (kg) 5.86 6 0.84 5.75 6 0.83 0.11
Length (cm) 60.1 6 2.20 60.0 6 25.6 0.10
HC (cm) 40.1 6 1.24 40.0 6 1.29 0.10
MUAC (cm) 13.2 6 1.15 13.0 6 1.12 0.22
Knee-heel length (cm) 16.1 6 0.75 16.0 6 0.90 0.10
Biceps skinfold thickness (mm) 6.84 6 1.24 6.72 6 1.38 0.12
Triceps skinfold thickness (mm) 8.84 6 1.62 8.60 6 1.71 0.24
Subscapular skinfold thickness (mm) 8.24 6 1.50 8.21 6 1.79 0.03
Plasma FAs (ng/mL) (n = 85) (n = 83)
DHA 70.2 6 23.8 76.4 6 23.2 26.20
EPA 23.0 (14.5, 35.5)
24.3 (16.1, 40.4) 21.30
AA 125 6 42.5 133 6 39.9 28.00
Percentage of total FAs
DHA 3.75 6 0.89 4.00 6 0.95 20.25
EPA 1.15 (0.81, 1.66) 1.31 (0.82, 2.03) 20.16
AA 6.66 6 1.41 6.90 6 1.51 20.24
Acute-phase proteins (n)8078
Plasma albumin (mg/L) 33.0 6 3.01 33.0 6 2.61 0.00
a-Acid glycoprotein (g/L) 0.95 (0.77, 0.11) 0.88 (0.69, 0.12) 0.07
C-reactive protein (mg/L) 3.02 (2.23, 5.31) 2.91 (2.22, 4.67) 0.11
Gut integrity (n)8582
Urinary LMR 0.15 (0.10, 0.22) 0.15 (0.12, 0.20) 0.00
Lactulose:lactose ratio 0.75 (0.53, 1.10) 0.72 (0.50, 0.98) 0.03
Lactulose percentage recovery 0.26 (0.19, 0.45) 0.24 (0.16, 0.34) 0.02
Mannitol percentage recovery 7.02 6 3.46 6.21 6 2.94 0.81
Intestinal inflammation 82 83
Calprotectin wet weight (mg/kg) 1029 (627, 1534) 1058 (610, 1639) 229
AA, arachidonic acid; FA, fatty acid; HC, head circumference; LMR, lactulose-mannitol ratio; MUAC, midupper arm
Fish-oil group mean or median minus control group mean or median.
Age on the first day of supplementation.
Mean 6 SD (all such values).
Median; 25th, 75th percentiles in parentheses (all such values).
available for 172 infants (87 infants in the fish-oil group and 85
infants in the control group) from which growth and other
outcomes could be analyzed (Figure 1). Baseline characteristics
of infants were distributed evenly with no large differences
observed between study groups (Table 1). Compliance rates
$90% were measured for 85% of infants (74 of 87 infants) in
the fish-oil group and 88% of infants (75 of 85 infants) in the
control group. The remaining 23 infants all showed compliance
rates .75%. Of infants treated, 155 infants (90%) came for their
outcome measurements at 12 mo of age. Eight infants from the
fish-oil group and 9 infants from the control group were lost to
follow-up because they moved away from the area.
Effect of supplementation on PUFA status
Fish-oil supplementation resulted in a significant increase in
the percentage of DHA and EPA in plasma total lipids, which
confirmed the tissue uptake of n23 LC-PUFAs in fish-oil–sup-
plemented infants (Table 2). Arachidonic acid (AA) and total
n26 FA concentrations did not differ significantly between fish-
oil and control groups. See Table 1 under “Supplemental data”
in the online issue for other FAs measured.
When compliance and the number of doses recei ve d were fitted to
the regression model, we observed similar results with some evi-
dence of an interaction between compliance and treatment on DHA
and EPA concentrations (P = 0.029 and P = 0.02 6 , respect i v e ly) .
Scatter plots of plasma DHA and EPA at 9 against 3 mo by
treatment group are shown in Figure 2. Elevated n23 LC-
PUFAs at 9 mo in the fish-oil compared with control groups can
be observed, although the effect was subtle for DHA. DHA
concentrations at 9 mo remained correlated with those at 3 mo in
the control group (r = 0.44). This result was less clear in the fish-
oil group (r = 0.17).
The relative percentages of DHA (0.77 6 0.392%), EPA
(0.27%; 25th, 75th percentiles: 0.16, 0.44), and AA (0.49 6
0.11) in the milk of mothers at baseline did not differ signifi-
cantly from those measured at the 9-mo follow-up visit, whereas
18:3n26 and 20:3n26 significantly increased (to 0.11 6 0.04%
and 0.34 6 0.10% at the endpoint, respectively). See Table 2
under “Supplemental data” in the online issue for an overview of
all breast-milk FAs measured.
Primary endpoints
With the use of intention-to-treat analysis, a statistically
significant larger MUAC z score (effect size: 0.31 z scores; 95%
CI: 0.06, 0.56 z scores; P = 0.017) was detected in the fish-oil
Plasma fatty acid endpoints by treatment groups
Fish-oil group
(n = 86)
Control group
(n = 83)
Effect size
(95% CI)
Main LC-PUFAs (percentage of total FA)
DHA 4.87 6 1.01
4.44 6 0.81 0.53 (0.28, 0.79) ,0.001
EPA 2.13 [1.66, 2.95]
1.34 [0.94, 1.72] 1.65 (1.45, 1.88)
AA 7.28 6 1.52 7.25 6 1.35 0.09 (20.33, 0.51) 0.680
Main LC-PUFAs (ng/mL)
DHA 70.0 6 20.6 65.4 6 16.3 5.54 (20.03, 11.2) 0.051
EPA 31.1 [22.8, 43.7] 19.3 [14.3, 25.0] 1.61 (1.38, 1.84)
AA 104 6 29.0 107 6 27.6 22.38 (210.8, 6.05) 0.578
Other FAs and FA indicators (ng/mL)
Saturated (8:0–18:0)
516 6 150 541 6 137 227.0 (270.8, 16.7) 0.224
Saturated (20:0–24:0)
11.6 6 2.79 11.8 6 3.60 20.17 (21.17, 0.83) 0.739
350 6 99.7 373 6 106 223.4 (254.4, 7.67) 0.139
18:3n23 4.86 6 2.87 4.76 6 2.16 0.05 (20.73, 0.84) 0.893
22:5n23 13.2 6 4.64 11.9 6 3.82 1.32 (0.00, 2.64) 0.051
18:2n26c 317 6 93.8 322 6 91.9 24.40 (233.0, 24.2) 0.761
20:3n26 17.1 6 5.80 19.1 6 6.49 21.93 (23.67, 20.10) 0.039
Total n23 FAs (ng/mL) 123; 41 104; 28 20 (9, 30) ,0.001
Total n26 FAs (ng/mL) 440; 118 452; 119 210 (246, 27) 0.595
22:5n26 2.59 6 1.00 3.32 6 1.24 20.76 (21.07, 20.44) ,0.001
Essential and nonessential PUFAs
1.88 6 0.39 1.75 6 0.34 0.14 (0.02, 0.25) 0.018
DHA:22:5n26 ratio 28.4 6 7.34 21.5 6 7.31 6.85 (4.64, 9.05) ,0.001
AA:EPA + DHA ratio 1.05 6 0.26 1.28 6 0.31 20.24(20.32, 20.16) ,0.001
AA, arachidonic acid; FA, fatty acid; LC-PUFA, long-chain PUFA.
General least-squares regression analysis with the dependent variable and treatment entered and baseline controlled
Mean 6 SD (all such values).
Median; 25th, 75th percentiles in brackets (all such values)
Because data were log transformed, effect sizes and CIs are expressed as the antilog of calculated CIs and regression
coefficients, which indicate the ratio of the geometric mean of fish-oil to control groups.
Includes 18:0, 17:0, 16:0, 15:0, 14:0, 13:0, 12:0, 11:0, 10:0, and 8:0.
Includes 24:0, 23:0, 22:0, 21:0, and 20:0.
Includes 14:1, 15:1, 16:1, 17:1, 18:1n9c, 20:1, 22:1n29, and 24:1.
Ratio of n26+n23ton29 unsaturated PUFAs. Ordinarily, n27 PUFAs should be included in the ratio as non-
essential FAs, but data for these were unavailable.
group (Table 3). A small significant difference for triceps
skinfold-thickness–for-age was also detected (P = 0.048). Linear
growth showed evidence of a benefit with a substantial effect
size of 0.79 z scores. However, CIs were wide, and the differ-
ence was not significant (95% CI: 20.27, 0.90; P = 0.084). This
difference had largely disappeared by 12 mo. See Tables 3 and 4
under “Supplemental data” in the online issue for a presentation
of anthropometric measures at 9 and 12 mo of age.
When subjects were remeasured at 12 mo of age, the significant
difference in MUAC measurements between groups was main-
tained. With respect to other proxy measures of infant adiposity,
skinfold-thickness measurements were also all significantly larger
in the sh-oil group than in the control group at this age, although
BMI-for-age z scores did not differ significantly (Table 4).
Gut permeability
No group differences between LMRs or percentage recoveries
of lactulose and mannitol were evident. The lactulose:lactose
ratio was also investigated, and again, there was no evidence of an
effect of treatment on gut integrity (Table 3). In comparison with
European references for healthy children (52, 53), only 5% of
infants had a normal LMR ,0.07. Similar results emerged with
respect to the significance of treatment effects when we repeated
the analyses on all primary endpoints, with our chosen co-
variates and for compliance controlled for.
There was no significant interaction between season, breast-
milk DHA, or breast-milk EPA and treatment on growth, the
LMR, or lactulose and mannitol recoveries (P . 0.09 for all). A
significant interaction between compliance and treatment (P =
0.012) was shown for LMR. However, the CI included 1.0, and
the effect size was trivial (1.01). There were no compliance-
treatment interactions for lactulose or mannitol recovery.
Secondary endpoints
Acute-phase proteins
PUFA supplementation did not reduce the relatively high
degree of systemic inflammation in infants (Table 5).
Fecal calprotectin
Although overall fecal calprotectin concentrations were very
high, there were no significant differences in the average or
proportion of elevated calprotectin concentrations between in-
fants in the 2 treatment groups. More than 85% of infants had
calprotectin concentrations higher than a European reference for
infants at 3 mo of age (54) (Table 5).
With the use of negative binomial regression analyses, we
showed evidence of no treatment effect when inspecting group
differences in rates of illness, fever, respiratory complaints,
vomiting, or nurse visits/doctor visits, referrals in infants. Al-
though the difference was not significant, diarrhea rates were far
higher (roughly 25%) in the control group than in the fish-oil
group (Table 6).
The logarithm of the number of visits was controlled for in
each analysis because the number of times a particular complaint
was reported increased with the number of times that the infant
was visited but possibly not in a straightforward, multiplicative
way. The results when adjusted for our chosen covariates and
compliance were similar, and no significant interactions between
compliance and treatment group on morbidity outcomes were
observed. The most common complaints were cough and re-
spiratory conditions followed by fever.
We finally investigated whether group differences existed for the
number of severe episodes of illnesses subjects experienced. The
number of episodes of illness that lasted for $3 d was compared
between groups by using a 2-sample t test with equal variances,
but no significant differences in severity (as judged by duration)
were shown for any of the morbidities assessed (P . 0.255 for
all). A total of 9 serious adverse events occurred, all of which
were reported to the trial safety monitor. Four of these events were
in the treatment group, and 6 events were in the control group.
Cognitive development at 12 mo
On both the Willatts Infant Planning and attention tests, we
observed no significant difference in performance between the 2
treatment groups (Table 7). There were no significant differences
FIGURE 2. Plasma DHA and EPA scattered at 9 compared with 3 mo by
treatment group (n = 168).
detected between intention scores or solutions, inattention rates, or
mean look times. In an attempt to retrieve the toy, infants pulled
the cloth off the table an equal number of times in control and fish-
oil groups (P = 0.918), which indicated that n23 LCP supple-
mentation had no ef fect on motor control (55). Sixteen percent of
infants were unable to show any form of intention for the retrie v al
of the toy whatsoever, and only 2% of infants were able to obtain
the maximum intention score. In the infant planning test only , we
showed sex differences between test scores. The average total
intentional solution score was significantly higher in boys than in
girls (average increase: 1.61 points; 95% CI: 0.35, 3.86 points; P =
0.012), and for intentional solutions, we observed a weak statis-
tical difference (P = 0.067). There were no sex differences in at-
tention test scores. Interobserver reliability was high on both the
total intention (r = 0.97; bias-corrected 95% CI: 0.936, 0.989) and
intentional solution scores (r = 0.92; bias-corrected 95% CI: 0.821,
0.961), and there was no significant evidence of a bias between
markers (P = 0.121 and P = 0.097, respecti vely ).
Effect of n23 LC-PUFA supplementation on primary endpoints at 9 mo by treatment group
Fish-oil group
(n = 87)
Control group
(n = 85)
Effect size
(95% CI) P
Growth (anthropometric z scores)
Weight-for-age 20.90 6 1.09
21.20 6 1.28 0.15 (20.08, 0.38) 0.208
Weight-for-length 20.57 6 0.99 20.76 6 1.10 0.12 (20.14, 0.38) 0.377
Length-for-age 20.79 6 1.02 21.07 6 1.30 0.79 (20.27, 0.90) 0.084
HC-for-age 20.52 6 0.84 20.64 6 1.06 20.01 (20.18, 0.17) 0.954
MUAC-for-age 20.27 6 0.92 20.66 6 1.18 0.31 (0.06, 0.56) 0.017
BMI-for-age 20.60 6 0.99 20.79 6 1.12 0.08 (20.16, 0.33) 0.503
Triceps skinfold thickness–for-age 20.01 6 0.85 20.30 6 1.09 0.27 (0.00, 0.55) 0.048
Subscapular skinfold thickness–for-age 0.41 6 1.12 0.27 6 1.29 0.16 (20.16, 0.48) 0.326
Gut integrity (n)8681
Mannitol percentage recovery 4.22 6 2.48 4.51 6 2.04 20.34 (21.04; 0.35) 0.332
0.22 [0.14, 0.37]
0.22 [0.15, 0.29] 0.96 (0.87, 1.07)
Lactulose:lactose ratio
0.50 [0.30, 0.91] 0.64 [0.42, 0.98] 0.79 (0.60, 1.05)
Lactulose percentage recovery
0.21 [0.11, 0.38] 0.23 [0.15, 0.32] 0.91 (0.72, 1.15)
HC, head circumference; LC-PUFA, long-chain PUFA; LMR, lactulose:mannitol ratio; MUAC, midupper arm
General least-squares regression analysis with the dependent variable and treatment entered and baseline controlled
for. Median growth measurements of each individual were used.
With the use of WHO reference curves (38, 39).
Mean 6 SD (all such values).
Data were log transformed.
Regression analysis fitting (log)lactulose on (log)mannitol with baseline values controlled for.
Median; 25th, 75th percentiles in brackets (all such values).
For log-transformed data, effect sizes and CIs are expressed as the antilog of calculated CIs and regression co-
efficients, which indicate the ratio of geometric means of fish-oil to control groups.
Regression analysis fitting (log)lactulose on (log)lactose with baseline values controlled for.
Anthropometric indexes at 12 mo of age by treatment group with baseline measures controlled for
Fish-oil group
(n = 79)
Control group
(n = 76)
Effect size
(95% CI)
Anthropometric z scores
Weight-for-age 21.09 6 1.13
21.41 6 1.21 0.11 (20.13, 0.35) 0.357
Weight-for-length 20.79 6 1.10 21.03 6 0.97 0.17 (20.09, 0.43) 0.207
Length-for-age -0.1.00 6 1.11 21.30 6 1.32 0.08 (20.15, 0.32) 0.489
HC-for-age 20.61 6 0.87 20.72 6 1.02 20.04 (20.24, 0.16) 0.713
MUAC-for-age 20.20 6 0.94 20.64 6 0.98 0.33 (0.09, 0.57) 0.008
BMI-for-age 20.69 6 1.12 20.90 6 0.94 0.09 (20.15, 0.34) 0.459
Triceps skinfold thickness–for-age 0.19 6 0.79 20.15 6 0.82 0.31 (0.06, 0.55) 0.014
Subscapular skinfold thickness–for-age 0.23 6 1.05 20.14 6 1.02 0.36 (0.06, 0.67) 0.019
HC, head circumference; MUAC, midupper arm circumference.
General least-squares regression analysis with the dependent variable and treatment entered and baseline con-
trolled for.
With the use of WHO reference curves (38, 39).
Mean 6 SD (all such values).
Associated covariates
Only 2.68% of mothers reported exclusively breastfeeding
their infants by the time they had reached 6 mo of age. Solid foods
were reportedly introduced in 31.5% of 3-mo-old infants, and all
infants were eating solid foods by 9 mo of age. In respect of rich
sources of preformed LC-PUFAs, 14% of infants had had some
form of egg in their diet by 6 mo. Roughly the same number of
infants had shared the family bowl, including dishes that con-
tained small amounts of dried fish. By 9 mo of age, roughly 80%
of infants had had some egg yolk or some form of fish. The most
common complementary food fed, by far , was a rice-based porridge.
Other frequently fed foods were bread, margarine, mayonnaise,
bananas, and cooking oil.
Maternal schooling
Education data were available for 94% of mothers whose
infants completed the cognitive testing, and of those infants, 75%
of them received some form of formal schooling. There were no
significant differences in the education level between mothers in
the 2 treatment groups, and no associations were shown between
the education levels of mothers and the performance of their
infants on any of the tests.
To our knowledge, this was the first publicly registered or
published study to investigate the effects of n23 LC-PUFA
supplementation during infancy on gut integrity, growth, and
cognitive development in infants from a low-income country.
Secondary endpoints, by treatment group
Effect size
(95% CI) P
Acute-phase proteins (n)8683
Plasma albumin (mg/L) 35.3 6 3.1
35.3 6 2.8 0.07 (20.83, 0.96)
AGP (g/L) 1.01 [0.85, 1.34]
1.03 [0.82, 1.36] 0.97 (0.88, 1.08)
CRP (mg/L) 4.7 [3.1, 8.2] 4.7 [3.2, 7.9] 0.98 (0.81, 1.19)
Intestinal inflammation (n)7669
Calprotectin dry weight (mg/kg) 78.0 [43, 120] 66.5 [46, 138] 0.90 (0.86, 1.42)
Calprotectin wet weight (mg/kg) 647 [357, 996] 552 [382, 1145]
Concentrations out of normal range
Plasma albumin
5/86 [0.77, 10.9]
3/83 [20.49, 7.71] 0.933
44/86 [40.4, 61.9] 43/83 [40.8, 62.8] 0.501
39/86 [34.6, 56.1] 36/83 [32.5, 54.3] 0.796
70/79 [81.4, 95.8] 62/74 [75.2, 92.4] 0.386
AGP, a1-acid glycoprotein; CRP, C-reactive protein.
Mean 6 SD (all such values).
General least-squares regression analysis with the dependent variable and treatment entered and baseline controlled
Median; 25th, 75th percentiles in brackets (all such values).
Because data were log transformed, effect sizes and CIs are expressed as the antilog of calculated CIs and regression
coefficients, which indicated the ratio of the geometric mean of fish-oil to control groups.
With the use of standard adult cutoff ranges from healthy individuals (CRP $5 mg/L, AGP $1 g/L, and albumin
#30 mg/L).
Proportion abnormal; 95% CI in brackets (percentage abnormal) (all such values).
Group differences were analyzed by using Pearson’s chi-squared test.
With the use of the European healthy reference value [calprotectin #263 mg/kg (54)].
Morbidity endpoints by treatment group
Morbidity rates
Fish-oil group
(n = 87)
Control group
(n = 85)
Effect size
(95% CI)
Unwell, any complaint
3088 0.13 (20.08, 0.34) 0.238
474 605 20.27 (20.61, 0.06) 0.110
1479 1297 0.11 (20.12, 0.34) 0.338
Respiratory complaints
1645 1503 0.06 (20.2, 0.32) 0.670
Nurse or doctor visits
186 161 0.13 (20.10, 0.36) 0.268
251 268 20.12 (20.56, 0.03) 0.570
Abnormal bleeds/other complaints
12 17
Negative binomial regression by using the number of visits an infant was reported ill or with a symptom as a negative
binomial variable with log(number of visits) controlled for.
Number of visits at which one or more symptoms were recorded.
Total recorded (all such values).
Number of visits at which any infant was reported to have had this complaint.
Too few observations to make a meaningful statistical comparison.
The intervention successfully increased infant n23 plasma FA
status. Supplementation also resulted in a 0.3-cm increase in
MUAC after 6 mo of intervention. At the 12-mo follow-up (ie,
3 mo after the end of the intervention) significant increases in
MUAC and all 3 skinfold-thickness measurements were detected
in the intervention group. Apart from a substantial but non-
significant increase in the length of 0.79 z scores in the fish-oil
group at 9 mo (P = 0.08), no additional effects on growth were
detected. There were no cross-sectional associations between
outcome variables and PUFA status; neither plasma nor breast
milk PUFA at 3 or 9 mo predicted urinary LMR, lactulose or
mannitol percentage recoveries, fecal calprotectin concentra-
tions, or cognitive-function scores. Therefore, results of the trial
provided insufficient evidence to support the primary hypotheses
that dietary n23 LC-PUFA supplementation improves the growth
performance of rural African infants and/or protects mucosal
epithelial integrity even at the very large dose used. Also, the
dietary n23 LC-PUFA supplement did not lead to reduced de-
grees of intestinal and systemic inflammation or reduced rates of
morbidity in these rural African infants.
A possible explanation for why the intervention achieved such
a modest impact is that the PUFA analysis of breast milk showed
that the average mother’s milk was at the higher end of the range
in EPA and DHA compared with that in breast milk of women in
most other populations (56, 57). Therefore, the majority of in-
fants aged 3–9 mo were ensured diets that supplied adequate
amounts of n23 FAs. It is likely that even at 9 mo of age, when
weaning foods contribute to a large part of the infant diet, breast
milk supplied most infants with substantial amounts of preformed
LC-PUFAs even when it was consumed in smaller volumes.
Together, DHA and EPA accounted for w1% of total FAs and
were measured (by applying reliable, validated methods) at con-
centrations that matched those in populations who consume
a large amount of fish, such as in the Philippines. Brenna et al
(56) measured the breast milk in 2472 women from 30 different
countries, and, in comparison with these results, breast-milk
DHA concentrations in Gambian women were shown to be
considerably high. Brenna et al (56) showed an average relative
DHA concentration of 0.32 6 0.22% (compared with the con-
centration of 0.77 6 0.39% shown in our sample of women).
Yuhas et al (57) showed average EPA concentrations of 9
different populations worldwide to range from 0.07 6 0.07% to
0.26 6 0.14%, whereas the Gambian mean was even higher than
this range (0.36 6 0.29%). However, average breast-milk AA
concentrations in Gambian women were similar to averages
globally (0.49 6 0.11% compared with 0.47 6 0.13%, re-
spectively). The reasons for these high PUFA levels are not cer-
tain. The Gambian diet is not considered to supply large quantities
of n23 LC-PUFAs, although precursor n23 FAs are regularly
consumed via green leafy vegetables. The conversion efficiency
may be particularly high in these women, possibly because of
polymorphisms of FA D S1 and FA DS 2 (FA desaturase) gene
clusters, but this relation remains untested.
Our data suggested that fish-oil administration may have
a delayed effect on body fat as shown by the sustained effect on
MUAC and significant increases in skinfold thicknesses of the
fish-oil group seen at 12 but not at 9 mo. This is not the first time
that such an effect has been observed. In a study that investigated
breastfed infants whose mothers were supplemented with fish oil
during lactation, an increased subscapular skinfold thickness was
also detected in infants of supplemented women but only at
follow-up 2 y after the intervention was ceased (58–60). Thus, the
impact of early n23 LC-PUFA supplementation may change
over time, which suggests the possibility of a (possibly epige-
netically mediated) memory effect.
The Willatts’ Infant Planning Test was chosen because it has
proven sensitive to past nutritional interventions in infants (46,
55) and has been successfully used in low-income countries (44,
45) where it has, for example, allowed the detection of differences
between groups of infants aged 7 mo after a 2-mo psychosocial
intervention (44). In contrast, LCPs in infant development, by
using standard generalized tests, have rarely shown any benefit.
DHA is important to cognitive processes supported by frontal
regions of the brain (61–66), where functions that integrate and
control attention and response components with long-term and
working memory take place. Studies on look duration in human
and primate infants have shown associations between n23FAs
or DHA and accelerated attention maturity (41, 46, 67, 68).
DHA has also been shown to improve synaptic efficiency (69)
and transmission speed (70), thereby theoretically aiding in in-
formation-processing efficiency. Therefore, tests that measure
frontal region processes, such as attention and problem solving,
Cognitive development endpoints by treatment group
Effect size
(95% CI) P
2-step Infant Planning Test (n)73 65
Average total intention score 4.63 6 3.77
4.45 6 3.71 0.20 (21.10, 1.46)
Average intentional solutions 0.44 6 0.52 0.43 6 0.54 0.01 (20.17, 0.19)
Toddler attention assessment (n)74 69
Inattention rate 2.38 [1.70, 2.91]
2.37 [1.70, 2.91] 0.98 (0.82, 1.81)
Mean look duration 23.8 [19.5, 33.9] 23.2 [17.2, 35,5] 1.01 (0.86, 1.20)
Assessments could not be made for the Infant Planning Test in 17 cases (6 cases in the sh-oil group and 11 cases in
the control group) and for the attention test in 12 cases (5 cases in the fish-oil group and 7 cases in the control group)
because the children were disturbed or crying or the video recording malfunctioned.
Mean 6 SD (all such values).
General least-squares regression analysis with the dependent variable and treatment entered.
Median; 25th, 75th percentiles in brackets (all such values).
Because data were log transformed, effect sizes and CIs are expressed as the antilog of calculated CIs and regression
coefficients, which indicate the ratio of the geometric mean of fish-oil to control groups.
may be more appropriate when examining n23 LCP in relation
to cognitive development.
Gambian infants scored poorly on the problem-solving test
compared with younger (9-mo-old) infants in Denmark (71), the
United States (72), and the United Kingdom (46). (It was not
possible to make valid comparisons with other reported studies that
used the 1- or 3-step test.) Apart from one study in Bangladesh (45),
the sex differences we observed were not seen in other studies. In
rural Gambia, sex distinctions appeared to be particularly pro-
nounced, possibly because of differences in maternal attention, and
marked differences in sex roles are the norm. However, a difference
in cognitive development first needs to be verified before inferences
about its causes and consequences can be made.
Strengths of this study
Because growth faltering is highly resistant to energy or
micronutrient supplementation [as shown in numerous studies
(73–78)] and so many interventions have failed to improve the
growth and gut integrity of Gambian infants (76, 79, 80), it was
hoped that n23 LC-PUFA supplementation would provide some
beneficial effect. Despite the supplementation of young infants
with a very large dose of n23–rich fish oil, administration of
supplements under direct observation, achievement of very high
compliance rates, and the demonstration of significant shifts in
plasma PUFA profiles at 9 mo, remarkably little effect was ob-
served on tested outcomes. Aided in part by the use of triplicate
measures on alternate days for primary outcomes at baseline and
9 mo, 95% CIs calculated for most endpoints were acceptably
narrow, which provided reasonable certainty that the study was
adequately powered to detect clinically meaningful effects. This
statement was less true for the lactulose-mannitol sugar per-
meability test for which, as indicated by the low intraclass
correlation coefficient, a high amount of error (mostly attribut-
able to the lactulose assay) was introduced during measurement.
This result may have partly been ascribed to our use of a field-
adapted method, the low reliability of which has, for the first
time to our knowledge, been shown.
Weaknesses of the study
Because of the high concentrations of n23 PUFAs in breast
milk and the very high rates of breastfeeding in this community,
it may be argued that the intervention was targeted at infants
who were already replete with n23 LC-PUFAs. Nevertheless,
the size of the dose was large enough to still further increase
plasma n23 LC-PUFA concentrations and warrant possible as-
sociated benefits. We had also speculated that high concentra-
tions of n23 PUFAs might have a topical effect on gut mucosae.
It is possible that a delayed intervention directed at children
receiving a lower (or absent) proportion of breast milk in their
diet, and, hence, likely to be deficient in all PUFAs (81), would
have shown a greater benefit. However, our early intervention
was intentionally predicated on the assumption that it would be
better to attempt to block the initial development of enteropathy
rather than attempt to redress the fully established gut damage,
which is slow to repair.
Growth faltering and environmental enteropathy is the result of
a complex set of mechanisms that involve varied physiologic and
environmental interactions. Although environmental enteropathy
appears to be clinically asymptomatic, its effect on growth is
imputed to be large, and its full effect on the child cannot be
known until an effective intervention to ameliorate or prevent the
condition is shown. Thus, we believe that the problem should
continue to be explored for the benefit of future generations in
The Gambia and elsewhere.
In conclusion, n23 LC-PUFAs remain critical to human
health and development, but breast-fed infants in rural Gambia
are ensured an adequate supply of preformed LC-PUFAs by
mother’s milk, which in the present sample proved considerably
rich in these FAs. A better understanding of the cause and path-
ogenesis of environmental enteropathy is recommended for as-
sisting in the development of effective interventions. Etiological
assumptions should be confirmed or refuted and the mucosal
immune response studied in further depth. The identification of
specific gut pathogens that lead to gut damage and consequent
immunoprophylactic approaches that target these and estab-
lished pathogens are recommended. The increased power of
analytic methods for the study of the human microbiome may
facilitate such exploration. The importance of attempts to ad-
dress the worldwide problems of poor hygiene and sanitation,
which lead to enteric infections in the first instance, should not
be undermined, and their priority should be considered high.
We thank the mothers and infants participating in this study and the staff of
MRC Keneba, especially Stephen Owens and Afam Ebirim for providing clin-
ical cover, and the field staff. Our thanks to Conor Doherty for Trial Safety
Monitoring activities and to Philip Calder who was the Trial Monitor. We
thank Peter Willatts for providing training on the conduct and scoring of
the Willatts Infant Planning Test. Laura Wang conducted the FA analyses.
Peter Lunn provided advice on the lactulose-mannitol assay.
The authors’ responsibilities were as follows—LFvdM and AMP: con-
ceived and designed the study with input from SEM and AJF and wrote the
manuscript with input from all authors; LFvdM: conducted the study with
the support of SEM and SD; AJF: was responsible for statistical aspects of
the study; KH: led the cognitive development part of the study and scored all
videos; SD: performed all cognitive tests; SY: was responsible for FA anal-
yses; and all authors: read and approved the final manuscript. LFvdM is
currently employed by Danone Research, Netherlands. None of the authors
had a conflict of interest.
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    • "Additionally, levels of EFA intake have not been measured in children in Tanzania. Furthermore, blood FA levels in populations of children from developing countries, specifically Tanzania, are mostly unknown [24, 25] with some exceptions [25][26][27][28][29][30][31][32]. Given the importance of EFAs, there is a need to assess whole blood FA levels and their relationship to growth in developing countries such as Tanzania [24, 33]. "
    [Show abstract] [Hide abstract] ABSTRACT: Background: In Tanzania, 35% of all children below five years of age are stunted. Dietary fatty acids (FA) are critical for growth and development. However, whole blood FA levels in Tanzanian children are poorly described. Objective: The objectives of this cross-sectional study were to assess 1) whole blood levels of essential fatty acids and 2) the association between whole blood FA levels and growth parameters in Tanzanian children 2-6 years of age. Methods: A drop of blood was collected on an antioxidant treated card and analyzed for FA composition. Weight and height were measured and z-scores calculated. Relationships between FAs and growth parameters were analyzed by linear regression. Results: Of the 334 children that participated, 30.3% were stunted. The average whole blood level of Mead acid was 0.15%. The anthropometric z-score height-for-age (HAZ) was inversely associated with Mead acid, the Mead acid to arachidonic acid (T/T) ratio, and total n-9 FA. Additionally, HAZ was positively associated with linoleic acid and total n-6 FA. BMI-for-age was positively associated with oleic acid, total n-9 FA and T/T ratio but inversely associated with arachidonic acid and total n-6 FA. Weight-for-height was inversely associated with arachidonic acid and total n-6 FAs and positively associated with oleic acid and total n-9 FA. Weight-for-age was not associated with any FA tested. Total n-3 FAs were not associated with any growth parameters measured. Conclusions: The EFA linoleic acid and the markers of FA deficiency were associated with HAZ, an indicator for stunting in 2-6 year old Tanzanian children. Total n-6, total n-9, and a number of individual FAs were associated with growth. Increasing dietary intake of EFA and n-6 FAs may be a strategy to combat stunting in this population.
    Full-text · Article · May 2016
    • "Long-chain polyunsaturated fatty acids (LC-PUFA), PUFA with chain lengths $C20 and $3 unsaturations, such as the arachidonic (ARA, 20:4n-6), eicosapentaenoic (EPA; 20:5n-3) and docosahexaenoic (DHA; 22:6n-3) acids, are essential components of biomembranes of all cells and tissues, and have crucial roles in growth, ontogenesis, reproduction, stress and immune responses as well as development of the nervous system [1,2]. In addition, they also have key roles in the inflammatory response and consequently in several inflammatory and pathological conditions, including metabolic disorders, cardiovascular and neurological diseases345. "
    [Show abstract] [Hide abstract] ABSTRACT: Both the spotted scat Scatophagus argus and rabbitfish Siganus canaliculatus belong to the few cultured herbivorous marine teleost, however, their fatty acyl desaturase (Fad) system involved in long-chain polyunsaturated fatty acid (LC-PUFA) biosynthesis are different. The S. argus has a △6 Fad, while the rabbitfish has △4 and △6/△5 Fad, which were the first report in vertebrate and marine teleost, respectively. In order to compare the characteristics of elongases of very long-chain fatty acids (Elovl) between them, two Elovl cDNAs were cloned from S. argus in the present study. One has 885 bp of open read fragment (ORF) encoding a protein with 294 amino acid (aa) showing Elovl5 activity functionally characterized by heterologous expression in yeast, which was primarily active for the elongation of C18 and C20 PUFA. The other has 915 bp of ORF coding for a 305 aa protein showing Elovl4 activity, which was more efficient in the elongation of C20 and C22 PUFA. Tissue distribution analyses by RT-PCR showed that elovl5 was highly expressed in liver compared to other tissues determined, whereas elovl4 transcripts were only detected in eye. The expression of elovl5 and elovl4 were significantly affected by dietary fatty acid composition, with highest expression of mRNA in liver and eye of fish fed a diet with an 18:3n-3/18:2n-6 ratio of 1.7:1. These results indicated that the S. argus has a similar Elovl system in the LC-PUFA biosynthetic pathway to that of rabbitfish although their Fad system was different, suggesting that the diversification of fish LC-PUFA biosynthesis specificities is more associated with its Fad system. These new insights expand our knowledge and understanding of the molecular basis and regulation of LC-PUFA biosynthesis in fish.
    Full-text · Article · Apr 2016
    • "A third trial (QS 7) showed that DHA supplementation during pregnancy was associated with a lower ponderal index in infants at birth [37]. The remaining 12 trials reported no significant effects of either maternal [34,3839404142 or child PUFA supplementation [21,22,30,31,33,35,43] on BMI, weight-for-height, or BF% of the child at ages ranging from 1 to 19 y. The 19 observational studies that studied PUFAs in relation to obesity reported inconsistent results (Table 2b). "
    [Show abstract] [Hide abstract] ABSTRACT: The importance of polyunsaturated fatty acid (PUFA) intake in fetal life and infancy has been widely studied in relation to child cognitive and visual development, but whether early life PUFA exposure is related to cardiometabolic risk factors is unclear. The focus of this systematic review was to evaluate the effects of PUFA dietary intake and blood levels during pregnancy, lactation, or early childhood (⩽ 5 y) on obesity, blood pressure, blood lipids, and insulin sensitivity. We identified 4,302 abstracts in the databases Embase, Medline and Cochrane Central (April 2014), of which 56 articles, reporting on 45 unique studies, met all selection criteria. Many of the included studies focused on obesity as an outcome (33 studies), whereas studies on insulin sensitivity were relatively scarce (6 studies). Overall, results for obesity, blood pressure, and blood lipids were inconsistent, with a few studies reporting effects in opposite directions and other studies that did not observe any effects of PUFAs on these outcomes. Four studies suggested beneficial effects of PUFAs on insulin sensitivity. We conclude that there is insufficient evidence to support a beneficial effect of PUFAs in fetal life or early childhood on obesity, blood pressure, or blood lipids. More research is needed to investigate the potential favorable effects of PUFAs on insulin sensitivity, and to examine the role of specific fatty acids in early life on later cardiometabolic health. Copyright © 2015. Published by Elsevier Ltd.
    Full-text · Article · May 2015
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