ONC: Dietary Supplements and Medical Food Supplements Containing Fish Oil (2013)

Study Design:
- Click here for explanation of classification scheme.
Quality Rating:
Research Purpose:
To investigate the impact of an omega three fatty acid  (n-3FA ) supplemented diet versus an arginine (ARG) supplemented diet in post-surgical oral and laryngeal cancer patients on nutrition variables, clinical outcome, postoperative infections, and wound complications.
Inclusion Criteria:
  • Post-surgical oral and laryngeal cancer patients
  • No recent weight loss (< 5% at 3 months prior to study)
  • Ambulatory
Exclusion Criteria:
  • Severely impaired hepatic function (t-bilirubin > 3.5 mg/dL)
  • Severely impaired renal function (creatinine > 2.5 mg/dL)
  • Ongoing infection
  • Fever in the preceeding month
  • Major gastrointestinal disease
  • Autoimmune disorders
  • Steroid treatment
  • Medication which could modulate metabolism and/or weight
Description of Study Protocol:

Recruitment Subjects were recruited from May 2002 to October 2003 at time of hospital discharge post surgery.

Design Subject were enrolled and randomized using sealed envelopes at time of discharge. Subjects were asked to consume either 2 cans of a n-3FA supplemented liquid nutritional supplement or 2 cans of a ARG supplemented liquid nutritional supplement for 12 weeks in addition to an oral diet of 30 Kcal/kg/day and 1.1 g protein/kg/day. Subjects were also instructed to complete regular physical activity (1 hour of walking per day).

Nutritional Composition of Liquid Nutritional Supplements

n-3 FA Supplement

(Group 1)

ARG Supplement

(Group 2)

Volume 240 ml     300 ml
Total Energy 295 Kcal 303 Kcal
    Total 15.96g 16.7g
    Free L-Agrinine - 3.7g
    Total 6.14g 8.3g
    EPA 1.01g 0.59g
    DHA 0.31g 0.37g
Carbohydrate 43.99g 40.2g
Dietary Fiber 2.64g 3g










Subjects completed 3 day food diaries at baseline (week 0) and week 12, which included 1 weekend day and 2 week days. Total energy and macronutrient intakes were calculated fromthis data. Alcohol intake and smoking habits were also measured.

Blinding used: Unclear. Patients were randomized with sealed envelopes, but it does not state anywhere else if the study participants, investigators or clinicians were blinded or not.

Intervention: Subjects were randomized using sealed envelopes to consume, in addition to oral diet, either 2 cans of an n-3FA enriched liquid nutritional supplement (1.32 g n-3FA/can) or 2 cans of an ARG containing liquid nutritional supplement (3.7g ARG/can)

Statistical Analysis The intent to treat analyses included:

  • Frequencies
  • Kolmogorov-Smirnov test (distribution of variables)
  • 2 tailed-paired or unpaired t-test
  • Freidman or Wilcoxon test
  • p< 0.05

Power calculation indicated 30 patients were necessary to detect an improvement of 5 kg with a p value <0.05 and power of 80%

Data Collection Summary:

Timing of Measurements

The following studies were completed at baseline (time of hospital discharge) and week 12:

  • Physical examination and medical history
  • Height
  • Weight
  • Body mass index (kg/m2)
  • Regional changes in body mass as measured by muscle circumferences and tricep skinfold measurement
  • Body composition as measured with bioelectrical impedance analysis (BIA) and used to calculate total body water, fat and fat-free mass
  • Postoperative complications (none, general infections, urinary tract infections, local, wound infections)
  • Gastrointestinal symptoms
  • Biochemical Indices
    • Albumin
    • Prealbumin
    • Transferrin
    • Lymphocytes
  • 3 day food diary (RD instructed how to complete)

Throughout the study patients were asked to record the number and/or portion of cans of supplement consumed.

Dependent Variables

  • Nutrition Variables as measured by anthropometrics (height, weight, BMI, BIA, skinfold assessments), GI symptoms,  biochemical indices (albumin , prealbumin , transferrin , lymphocytes), and 3 day food diary 
  • Clinical Outcome as measured by presence of post-operative complications
  • Postoperative infections as measured by presence or absence
  • Wound complications as measured by presence or absence

Independent Variables Intake of of n-3FA or ARG supplemented liquid nutritional supplements

Description of Actual Data Sample:

Initial N: 73 [38 (36 male, 2 female) n-3FA group; 35 (32 male, 3 female) ARG group] 

Attrition (final N): 73 [38 (36 male, 2 female) n-3FA group; 35 (32 male, 3 female) ARG group] 

Age: 60.2 ± 11.15 years n-3FA group; 62.5 ± 11.4 years ARG group

Ethnicity: Not specified

Other relevant demographics:

Patient Demographic Variables
Variable n-3FA Group ARG Group
Smoking Habit 11.4%     13.2%
Alcohol Habit 17.2% 21.1%
Disease Stage    
    I 0 0
    II 8 4
    III     10 9
    IV 20 22
    Oral Cavity 9 8
    Larynx 29 27









No statistical differences between groups.


Patient Demographic Variables
Variable n-3FA Group ARG Group
Body Weight 65.5 ± 11.5 kg 68.2 ± 10.8 kg
Body Mass Index 23.81 ± 3.7 kg 24.6 ± 3.3 kg
Fat Free Mass 53.1 ± 8.7 kg 52.1 ± 8 kg
Fat Mass     15.4 ± 6.6 kg 16.7 ± 5.7 kg
Tricep Skinfold     10.9 ± 4.7 mm 11.3 ± 5.4 mm
Arm Circumference     27.4 ± 3.4 cm 27.4 ± 2.8 cm






Location: Hospital Rio Hortega and Hospital Clinico, Valladolid, Spain

Summary of Results:



n-3FA Group

Measures and confidence intervals

ARG group

Measures and confidence intervals

Statistical Significance of Group Difference

Nutrition Variables      

Albumin, g/dL



3.12 ± 0.9 

3.01 ± 0.57 NS
    3 Months 4.26 ± 0.76* 4.12 ± 0.81* NS

Prealbumin, mg/dL




    Basal 20.7 ± 7.1 21.8 ± 7.1 NS
    3 Months 27.2 ± 5.7* 25.36 ±6.8* NS

Transferrin, mg/dL

    Basal 184.4 ± 41.1 177.7 ± 38.9 NS
    3 Months 245.39 ± 44.4* 231.9 ± 59.2* NS
Lymphocytes, 103 microl/mm3      
    Basal 1,538 ± 454 1,596 ± 568 NS
    3 Months 2,090 ± 1,158* 2,270 ± 841* NS
Weight, kg      
    Basal 65.5 ± 11.5 68.2 ± 10 NS
    3 Months 70.4 ± 11.1* 69.1 ± 11.4 NS
Fat Free Mass, kg      
    Basal 53.1 ± 8.7 52.1 ± 8 NS
    3 Months 52.1 ± 8.6 52.9 ± 8.4 NS
Fat Mass, kg      
    Basal 15.4 ± 6.6 16.7 ± 5.7 NS
    3 Months 18.1 ± 8.4* 16.4 ± 6.5 NS
Tricep Skinfold, mm      
    Basal 10.9 ± 4.7 11.3 ± 5.4 NS
    3 Months 12.35 ± 6.1* 11.4 ± 4.5 NS
Arm Circumference, cm      
    Basal 27.4 ± 3.4 27.4 ± 2.8 NS
    3 Months 27.7 ± 4.4 27.7 ± 3.3     NS

* = Basal vs. 3 month values p< 0.05

Nutrition Variables

Duration of Supplementation:

  • n-3FA Group: 86.3 ± 26 days
  • ARG Group: 90 ± 22.6 days
  • Non-significant difference

Volume of Supplement Consumed:

  • n-3FA Group: 1.5 ± 0.52 units  for 1.6 gm EPA/day
  • ARG Group: 1.5 ± 0.52 units  for 1.6 gm EPA/day
  • Non-significant difference

Total Calorie Consumption:

  • n-3FA Group: 2,034 ± 501 Kcal/day 
  • ARG Group: 1,948 ± 607 Kcal/day 
  • Non-significant difference

Total Protein Consumption:

  • n-3FA Group: 95.68 ± 40.4 g/day 
  • ARG Group: 94.1 ± 28 g/day 
  • Non-significant difference

Gastrointestinal Intolerance:

  • n-3FA Group: 0 incidences
  • ARG Group: 0 incidences

Biochemical Indices:

  • Significant in-group improvement at 3 months in ARG and n-3FA group in all biochemical indices
  • No significant difference between groups

Anthropometric Parameters:

  • Significant increase in weight, fat mass, and tricep skinfold at 3 months in n-3FA group only
  • No significant difference between groups

Infections Complications

  • n-3FA Group: 0% (n=0)
  • ARG Group: 8.57% (n=3)
  • Non-significant difference

Other Findings

Alcohol and smoking habits did not affect results

Author Conclusion:
Outpatient ambulatory supplementation of oral diet with n-3FA supplemented liquid nutritional supplements led to significant improvements in weight, increases in body weight, and increases in serum protein levels after 3 months of daily supplementation. Further studies are warranted to examine the potential role of n-3FA enriched supplement in an outpatient setting.
Funding Source:
University/Hospital: Hospital Rio Hortega and Hospital Clinico University of Valladolid (Spain)
Reviewer Comments:

This study appears to be well designed and well written. There was limited information on alteration of catabolic processes as the study did not collect data on serum cytokines. Overall oral intake and supplement compliance was good and similar to that presented in other studies of immune enhanced liquid nutritional supplements:


  • No information provided on funding source
  • Would have been helpful to compare nutritional intake (calories/protein) at baseline to 3 months to see if any changes occurred.
  • NO control group- The prescribed diet (30 kcal/kg and 1.1 gm/kg) may have been adequate for both groups to show significant improvement in nutritional variables and not necessarily a result of an immune-enhanced nutritional supplement
  • Did not evaluate for other sources of n-3fa and Arg in diet

Subjects were only included if they had lost less than 5% of their body weight over the past 3 months, this is not always characteristic of head and neck patients.

No control supplement which did not contain immune-enhancing ingredient to assess the effect of non-supplemented liquid nutritional supplements on weight.

7/2006 Re-analysis: There was limited information on alteration of catabolic processes by lipids as the study did not collect data on serum cytokines or metabolic processes.

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? No
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%.) N/A
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for? Yes
  4.4. Were reasons for withdrawals similar across groups? N/A
  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? ???
  5.1. In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate? ???
  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.) ???
  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? Yes
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? ???
  10.1. Were sources of funding and investigators' affiliations described? No
  10.2. Was the study free from apparent conflict of interest? Yes