EAL

BF: Dietary Factors, Breast Milk and Infant Outcomes (2008)

Citation:

Lauritzen L, Jørgensen MH, Mikkelsen TB, Skovgaard M, Straarup EM, Olsen SF, Høy CE, Michaelsen KF. Maternal fish oil supplementation in lactation: effect on visual acuity and n−3 fatty acid content of infant erythrocytes. Lipids. 2004; 39 (3): 195-206.

PubMed ID: 15233397

Study Design:

Randomized Controlled Trial

Class:

A - Click here for explanation of classification scheme.

Quality Rating:

POSITIVE: See Quality Criteria Checklist below.

Research Purpose:

To examine if fish oil supplementation in lactating mothers improves acuity performance of breast-fed infants
To investigate how fish oil supplementation in lactating mothers affects the n-3 long-chain polyunsaturated fatty acid content of breast milk
To investigate how fish oil supplementation in lactating mothers affects fatty acid composition in infant erythrocytes.

Inclusion Criteria:

Danish mothers with habitual fish intake less than the 50th percentile of the Danish National Birth Cohort (according to a quantitative 300-item food frequency questionnaire)
Uncomplicated pregnancy
Pre-pregnancy BMI less than 30
No metabolic disorders
Intend to breastfeed for at least four months
Healthy newborns (no admission to a neonatal department)
Full-term newborn (37 weeks to 43 weeks of gestation)
Singleton infant
infant with normal weight for gestation
Infant with Apgar score more than seven at five minutes after delivery
Able to start supplement within two weeks after birth.

Exclusion Criteria:

None except not meeting all inclusion criteria.

Description of Study Protocol:

Recruitment: Danish National Birth Cohort mothers with fish intake less than the 50th percentile
Design: Randomized controlled trial; block randomization according to mean parental education
Blinding used: Double blinded (investigator and participating families)
Intervention: Subjects were randomly assigned to receive 4.5g fish oil [1.5g per day of long-chain n-3 fatty acid (n−3 LCPUFA)] or olive oil supplements. Supplementation started within a week after delivery and lasted four months. Supplements came in form of capsules, added to musli bars or added to cookies.
Statistical analysis: Chi-square, one-way ANOVA, linear regression with Bonferroni adjustment, Pearson's correlation, Kruskall-Wallis test, Mann-Whitney U-test, Kendall's correlation.

Data Collection Summary:

Timing of Measurements

Pre-enrollment visit (average at week 36.5 of gestation, four weeks before birth)
Within one week following birth
When infant was two months old
When infant was four months old.

Dependent Variables

Breast-milk content: Measured within a week following birth and when infants were two months of age and four month of age
Infant red blood cell (RBC) analysis: Blood sample taken when infants were four months old
Maternal RBC analysis: Blood sample taken when infants were four months old
Swept visual evoked potential (SWEEP-VEP), as a measure of visual acuity of the infant; when infants were two months and four months old.

Independent Variables

Treatment assignment (fish oil or olive oil).

Other Variables

Maternal demographic and social information: Collected at pre-enrollment visit
Infant head circumference: Measured within a week following birth
Infant weight and length: Measured when infants were two months and four months old
Maternal fish intake: Measured using food frequency questionnaire used in the Danish National Birth Cohort; measured when infants were two months and four months old
Breast milk consumption by infant was categorized into percentage of infant's energy intake: 100%, more than 90%, 75% to 90%, 50% to 75% and less than 50%.

Description of Actual Data Sample:

Initial N: 122 mothers randomized (62 in fish oil, 60 in olive oil)
Attrition (final N): 100 mothers (53 in fish oil, 47 in olive oil)
Maternal age: Olive oil group, 30.2±4.1 years; fish oil group, 29.6±4.3 years
Gestational age: Olive oil group, 40.1±1.2 weeks; fish oil group, 40.1±1.1 weeks
Sex of infants: Olive oil group, 28 males and 32 females; fish oil group, 37 males and 25 females
Infant head circumference: Olive oil group, 35.7±1.5cm; fish oil group, 36.1±1.3cm
Habitual daily n-3 long-chain fatty acid intake: Olive oil group: 0.3±0.3g; fish oil group, 0.3±0.3g
Habitual daily n-6 fatty acid intake: Olive oil group, 9±3.3g; fish oil group, 9.1±3.6g.

Summary of Results:

Changes in N-3 Fatty Acids and Arachidonic Acids of Infant RBCs

After four months of maternal supplementation and breastfeeding, infant RBCs in fish oil-supplemented group contained significantly more docosahexaenoic acid (DHA) and eicosapentaenoic (EPA) than those in the olive oil-supplemented group (both P<0.001). On the other hand, arachidonic (AA) contents of were similar between fish oil-supplemented group and olive oil-supplemented group. Ratio of n-6:n-3 fatty acids in infant RBCs was significantly greater in olive-oil group than fish-oil group (both P<0.001).

Fatty Acid Composition of Infant Red Blood Cells at Four-month Follow-up During Trial in Different Treatment Groups
(Expressed as Percentage of Total Fatty Acid)

	Olive Oil Group	Fish Oil Group
EPA 20:5 (n-3)	0.54±0.24	1.21±0.58*
DHA 22:6 (n-3)	6.29±1.71	8.72±2.40*
AA 20:4 (n-6)	16.18±2.38	14.86±1.67
N-6:n-3 Ratio	3.64±1.02	2.65±1.31

*P<0.001.

Fatty Acid Content of Breast Milk

At baseline (one week after giving birth), DHA, EPA and AA contents of breast milk were not different between fish oil-supplemented group and olive oil-supplemented group. However, after two months and after four months, breast milk from mothers in fish oil-supplemented group contained significantly more DHA and EPA than those in the olive oil-supplemented group (both P<0.001). AA contents of breast milk remain similar between fish oil-supplemented group and olive oil-supplemented group. Ratio of n-6:n-3 fatty acids in breast milk was similar between fish oil-supplemented group and olive oil-supplemented group at baseline, but became significantly greater in olive-oil group than fish-oil group at both two-month and four-month follow-up (both P<0.001).

Fatty Acid Composition of Breast Milk During Trial in Different Treatment Groups
(Expressed as Percentage of Total Fatty Acid)

	Week One		Two Months		Four Months
	Olive oil group	Fish oil group	Olive oil group	Fish oil group	Olive oil group	Fish oil group
EPA 20:5 (n-3)	0.17±0.07	0.17±0.05	0.08±0.08	0.28±0.13*	0.13±0.07	0.30±0.14*
DHA 22:6 (n-3)	0.67±0.28	0.66±0.23	0.30±0.36	1.16±0.45*	0.41±0.20	1.34±0.67*
AA 20:4 (n-6)	0.74±0.13	0.76±0.16	0.43±0.09	0.44±0.09	0.48±0.10	0.51±0.09
n-6/n-3 ratio	5.52±1.21	5.74±1.22	6.06±1.57	3.78±1.12*	6.51±1.77	4.22±1.80*

*P<0.001.

Brief description on the neurodevelopemental outcome of the infants

There was no significance difference in infants' visual acuity as measured by VEP between fish oil-supplemented group and olive oil-supplemented group at both two months and four months of age.

Visual Acuity of the Infants at Two Months and Four Months Age

	Olive Oil Group	Fish Oil Group
Number of Infants with SWEEP-VEP Successfully Done at Two Months	46	42
Mean Acuity at Two Months	0.84±0.08	0.84±0.09
Number of Infants with SWEEP-VEP Successfully Done at Four Months	45	52
Mean Acuity at Four Months	0.64±0.09	0.62±0.08

Other

There is significant positive correlation between infant RBC DHA content and DHA level of breastmilk at four-month follow-up (r=0.564, P<0.001). There was no significant difference in supplementation compliance, exclusivitiy of breastfeeding, breast-milk intake and proportion of breast-fed infants between the two groups.

	Olive Oil Group	Fish Oil Group
Compliance (Percentage Taken of Given Dose) at Four Months	87±9	88±9
Exclusively Breast-Fed at Four Months	74.5	62.3
Estimated Breast-Milk Intake During the Fourth Month (Percentage of Total Intake)	93±19	86±28
Infants Breast-Fed <50% (Percentage)	6.4	17

Author Conclusion:

Maternal fish oil supplement increased DHA, EPA and other n-3 long-chain polyunsaturated fatty acids in breast milk and infant RBCs. Changes in breast milk n-3 long-chain polyunsaturated fatty acids may affect infant visual development.

Funding Source:

Government:

The Danish Research and Development Program for Food and Technology and

Industry:

BASF Aktiengesellschaft

Pharmaceutical/Dietary Supplement Company:

Reviewer Comments:

Note that volunteers with fish intake more than the 74th percentile were recruited for a reference group, but were not considered in the randomization and treatment. Therefore, information for this group of subjects was not collected in this worksheet.

This article is an earlier publication of Lauritzen et al. 2005. The two articles are about the same trial.

Quality Criteria Checklist: Primary Research
Relevance Questions
	1.	Would implementing the studied intervention or procedure (if found successful) result in improved outcomes for the patients/clients/population group? (Not Applicable for some epidemiological studies)	Yes
	2.	Did the authors study an outcome (dependent variable) or topic that the patients/clients/population group would care about?	Yes
	3.	Is the focus of the intervention or procedure (independent variable) or topic of study a common issue of concern to dieteticspractice?	Yes
	4.	Is the intervention or procedure feasible? (NA for some epidemiological studies)	Yes

Validity Questions
1.	Was the research question clearly stated?		Yes
	1.1.	Was (were) the specific intervention(s) or procedure(s) [independent variable(s)] identified?	Yes
	1.2.	Was (were) the outcome(s) [dependent variable(s)] clearly indicated?	Yes
	1.3.	Were the target population and setting specified?	Yes
2.	Was the selection of study subjects/patients free from bias?		Yes
	2.1.	Were inclusion/exclusion criteria specified (e.g., risk, point in disease progression, diagnostic or prognosis criteria), and with sufficient detail and without omitting criteria critical to the study?	Yes
	2.2.	Were criteria applied equally to all study groups?	Yes
	2.3.	Were health, demographics, and other characteristics of subjects described?	Yes
	2.4.	Were the subjects/patients a representative sample of the relevant population?	Yes
3.	Were study groups comparable?		Yes
	3.1.	Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT)	Yes
	3.2.	Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline?	Yes
	3.3.	Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.)	Yes
	3.4.	If cohort study or cross-sectional study, were groups comparable on important confounding factors and/or were preexisting differences accounted for by using appropriate adjustments in statistical analysis?	N/A
	3.5.	If case control study, were potential confounding factors comparable for cases and controls? (If case series or trial with subjects serving as own control, this criterion is not applicable.)	N/A
	3.6.	If diagnostic test, was there an independent blind comparison with an appropriate reference standard (e.g., "gold standard")?	N/A
4.	Was method of handling withdrawals described?		Yes
	4.1.	Were follow-up methods described and the same for all groups?	Yes
	4.2.	Was the number, characteristics of withdrawals (i.e., dropouts, lost to follow up, attrition rate) and/or response rate (cross-sectional studies) described for each group? (Follow up goal for a strong study is 80%.)	Yes
	4.3.	Were all enrolled subjects/patients (in the original sample) accounted for?	Yes
	4.4.	Were reasons for withdrawals similar across groups?	Yes
	4.5.	If diagnostic test, was decision to perform reference test not dependent on results of test under study?	N/A
5.	Was blinding used to prevent introduction of bias?		Yes
	5.1.	In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate?	Yes
	5.2.	Were data collectors blinded for outcomes assessment? (If outcome is measured using an objective test, such as a lab value, this criterion is assumed to be met.)	Yes
	5.3.	In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded?	N/A
	5.4.	In case control study, was case definition explicit and case ascertainment not influenced by exposure status?	N/A
	5.5.	In diagnostic study, were test results blinded to patient history and other test results?	N/A
6.	Were intervention/therapeutic regimens/exposure factor or procedure and any comparison(s) described in detail? Were interveningfactors described?		Yes
	6.1.	In RCT or other intervention trial, were protocols described for all regimens studied?	Yes
	6.2.	In observational study, were interventions, study settings, and clinicians/provider described?	N/A
	6.3.	Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect?	Yes
	6.4.	Was the amount of exposure and, if relevant, subject/patient compliance measured?	Yes
	6.5.	Were co-interventions (e.g., ancillary treatments, other therapies) described?	N/A
	6.6.	Were extra or unplanned treatments described?	N/A
	6.7.	Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups?	Yes
	6.8.	In diagnostic study, were details of test administration and replication sufficient?	N/A
7.	Were outcomes clearly defined and the measurements valid and reliable?		Yes
	7.1.	Were primary and secondary endpoints described and relevant to the question?	Yes
	7.2.	Were nutrition measures appropriate to question and outcomes of concern?	Yes
	7.3.	Was the period of follow-up long enough for important outcome(s) to occur?	Yes
	7.4.	Were the observations and measurements based on standard, valid, and reliable data collection instruments/tests/procedures?	Yes
	7.5.	Was the measurement of effect at an appropriate level of precision?	Yes
	7.6.	Were other factors accounted for (measured) that could affect outcomes?	Yes
	7.7.	Were the measurements conducted consistently across groups?	Yes
8.	Was the statistical analysis appropriate for the study design and type of outcome indicators?		Yes
	8.1.	Were statistical analyses adequately described and the results reported appropriately?	Yes
	8.2.	Were correct statistical tests used and assumptions of test not violated?	Yes
	8.3.	Were statistics reported with levels of significance and/or confidence intervals?	Yes
	8.4.	Was "intent to treat" analysis of outcomes done (and as appropriate, was there an analysis of outcomes for those maximally exposed or a dose-response analysis)?	Yes
	8.5.	Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)?	Yes
	8.6.	Was clinical significance as well as statistical significance reported?	No
	8.7.	If negative findings, was a power calculation reported to address type 2 error?	N/A
9.	Are conclusions supported by results with biases and limitations taken into consideration?		Yes
	9.1.	Is there a discussion of findings?	Yes
	9.2.	Are biases and study limitations identified and discussed?	Yes
10.	Is bias due to study's funding or sponsorship unlikely?		Yes
	10.1.	Were sources of funding and investigators' affiliations described?	Yes
	10.2.	Was the study free from apparent conflict of interest?	Yes