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


De Luis, D.A., Izaola, O., Aller, R., Cuellar, L., Terroba, M.C., Martin, T. A randomized clinical trial with two omega-3 fatty acid enhanced oral suplements in head and neck cancer ambulatory patients. Eur Rev Med Pharmacol Sci.  2008; 12: 177-181.

PubMed ID: 18700689
Study Design:
Non-Controlled Trial
D - Click here for explanation of classification scheme.
Quality Rating:
Positive POSITIVE: See Quality Criteria Checklist below.
Research Purpose:

To investigate whether oral ambulatory nutrition of post-surgical  head and neck cancer patients with recent weight loss, using two different omega 3 fatty acids enhanced diets could improve nutritional variables as well as clinical outcomes.

Inclusion Criteria:
  • Diagnosis of oral and laryngeal cancer
  • Recent weight loss of more than 5% during previous three months
  • Ambulatory patient
  • Post-surgical patient.
Exclusion Criteria:
  • Severely impaired hepatic function (total bilirubin concentration more than 3.5mg per dL) and renal function (serum creatinine concentration more than 2.5mg per dL)
  • Ongoing infections
  • Major gastrointestinal disease
  • Autoimmune disorders
  • Steroids treatment
  • Use of medications could modulate metabolism or weight.
Description of Study Protocol:


Recruited upon hospital discharge after surgery.


At hospital discharge, post-surgical patients with head and neck cancer were asked to consume two cans per day of either a specially designed omega 3 fatty acid-enhanced supplement with a high ratio of omega three to omega six or an omega 3 fatty acid-enhanced supplement with a low ratio of omega 3 to omega 6. Three-day diet records were completed at baseline and week 12 to assess patient's dietary intakes. Supplement consumption was recorded by the patient. Weight, bipolar body electrical bioimpedance and body mass measures were taken in addition to fasting blood samples to evaluate albumin, prealbumin, transferrin and lymphocytes.


Omega 3 fatty acid enhanced supplement twice daily; high omega 3 to omega 6 ratio or low omega 3:omega 6 ratio.

Statistical Analysis

  • Distribution of variables analyzed with Kolmogorov-Smirnov test
  • Quantitative variables with normal distribution analyzed with two-tailed paired or unpaired Student's T-test and analysis of variance as needed
  • Non-parametric variables analyzed with Friedman and Wilcoxon test
  • P<0.05 considered statistically significant
  • 30 patients in each group were necessary to detect an improvement of 5kg with a P<0.05 and a power of 80%. 
Data Collection Summary:

Timing of Measurements

  • Baseline studies conducted at hospital discharge including history and physical examination evaluating height, weight, body mass index, circumferences and triceps skin fold of the midarm with an additional bioimpedance
  • Physical examination repeated at 12 week
  • Complications and gastrointestinal problems recorded at baseline and 12 weeks
  • Fasting blood samples were drawn for measurement of albumin, prealbumin, transferrin and lymphocytes at baseline and 12 weeks
  • Dietary intake evaluated with patient recorded three-day (two weekdays and one weekend day) diet diaries completed at baseline and 12 weeks
  • Amount of supplements consumed recorded by patient daily.

Dependent Variables

  • Weight (kg)
  • Fat-free mass (kg)
  • Fat mass (kg)
  • Tricep skin fold (mm)
  • Arm circumference (cm)
  • Albumin (g per dL)
  • Prealbumin (mg per dL)
  • Transferrin (mg per dL)
  • Lymphocytes (103uL per mm3)

Independent Variables

Specific formulation of oral nutrition supplement enhanced with omega 3 fatty acids.

Control Variables

  • Age
  • Gender
  • Disease stage
  • Diagnosis of disease
  • Gastrointestinal tolerance
  • Infection rates
  • Adherence to supplement prescription
  • Smoking habit
  • Alcohol consumption.
Description of Actual Data Sample:
  • Initial N: 65 subjects (six females, 59 males)
  • Attrition (final N): 65 (six females, 59 males)
  • Age: 63.7±10.9 years.

Other relevant demographics:

  • No significant difference in disease stage between two groups
  • No significant differences with regard to gender, mean age, body, weight, location and stage of tumor between study groups.



  • Group 1 (high ratio of omega 3 to omega 6): 24.7±4.2 years
  • Group 2 (low ratio of omega 3 to omega 6): 24.7±5.7 years.


Hospital Clinico, University of Valladolid, Valladolid, Spain. 

Summary of Results:

 Key Findings

  • No significant intergroup differences in improvement of the three plasma proteins were detected
  • No differences were detected in anthropometric parameters.

Group I, Baseline

(31 patients)

Group I, 12 Weeks

Group II, Baseline

(34 patients)

Group II, 12 Weeks
Albumin (g per dL) 3.14±0.9


P<0.05 with basal values in each group



P<0.05 with basal values in each group

Prealbumin (mg per dL) 20.7±7.1


P<0.05 with basal values in each group



P<0.05 with basal values in each group

Transferrin (mg per dL) 184.4±41.1


P<0.05 with basal values in each group



P<0.05 with basal values in each group

Lymphocytes (103ul per mm3) 1,538±54 2,090±1158 1,644±520 1,790±541
Weight (kg) 70.3±13.5 70.8±12.9 69.4±15.5 69.8±15.4
Fat-free mass (kg) 53.7±8.7 52.7±8.6 51.1±8 49.4±8.4
Fat mass (kg) 15.8±6.6 18.1±8.4 16.7±5.7 17.5±6.5
Tricep skin fold (mm) 11.5±4.7 11.8±6.1 11.6±6.5 11.3±5.6
Arm circumference (cm) 27.7±3.4 27.6±4.4 27.7±3.2 27.9±3.3


Other Findings

  • No significant differences with regards to gender, mean age, body weight, location and stage of tumor
  • No differences in alcohol habit and smoking habit among groups
  • Duration of supplementation in both groups was similar with an average duration of 85.8±26 days in group I and 88.9±22.6 days for group II; average intake was 1.6±0.62 units per day
  • Total calorie and protein consumption based on both formula and dietary intake with three-day food records were similar in both groups
  • Gastrointestinal tolerance with both formulas was good without statistical differences
  • No vomiting episodes were reported
  • Post-operative infectious complications were similar in both groups.
Author Conclusion:

Findings show that both omega-3-enhanced enteral formulas improved blood protein concentrations with a weight stabilization in post-surgical patients with head and neck cancer.

Funding Source:
University/Hospital: University of Valladolid
Reviewer Comments:
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? No
  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? Yes
  6.6. Were extra or unplanned treatments described? Yes
  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)? N/A
  8.6. Was clinical significance as well as statistical significance reported? Yes
  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? No
  10.1. Were sources of funding and investigators' affiliations described? No
  10.2. Was the study free from apparent conflict of interest? ???