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Trial registered on ANZCTR

Registration number
Ethics application status
Submitted, not yet approved
Date submitted
Date registered
Date last updated
Type of registration
Prospectively registered

Titles & IDs
Public title
Can fish oil supplementation lead to cognitive enhancement in Type 2 Diabetes?
Scientific title
Efficacy of a dietary intervention with Omega-3-DHA to enhance cognitive performance in Type 2 Diabetes.
Secondary ID [1] 288462 0
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Type 2 Diabetes Mellitus 297492 0
Cognitive decline 297493 0
Condition category
Condition code
Metabolic and Endocrine 297680 297680 0 0
Neurological 297681 297681 0 0
Other neurological disorders
Diet and Nutrition 297682 297682 0 0
Other diet and nutrition disorders

Study type
Description of intervention(s) / exposure
This project involves a medium-term (6-month) randomized, parallel dietary intervention clinical trial. Subjects will be recruited from the 4th year podiatry clinics at the La Trobe Health Sciences Clinic and randomized in one of 2 arms of the trial: (1) placebo supplementation or (2) omega-3 DHA supplementation. Screening, recruitment and intervention are anticipated to occur over a 1 year period. By the end of the second year, data collation and analysis will be finalized.

The subject pool will comprise patients with Type 2 Diabetes attending podiatry clinics at La Trobe Health Science Clinic. A list of all patients attending clinic on a given day, 50 years or over in age with Type 2 diabetes will be generated from the booking system. Patients will be invited to participate by the researcher in a separate clinic room where the study will be described. If patients are willing to participate they will be invited to complete a standard survey (SF12) assessing their quality of life. In addition, a background questionnaire will provide socio-demographic data, including age, gender, education and past medical history, current medications and physical activity. We will collect information on nutritional supplements, including prescribed ones. Participants will be asked to complete a Food Frequency Questionnaire and a 3-day food diary to eliminate patients already taking fish oil supplements and to monitor dietary confounders. The screening process is anticipated to take 20 mins and can be completed during appointment waiting time.

Additional recruitment material and advertising will be placed on the walls of the waiting room with contact details of researchers. Interested participants who contact the researcher can be screened on the phone and food frequency questionnaires and diaries can be mailed out. A prepaid envelope will be provided to return the surveys/ questionnaire.

This study is a double blinded randomised controlled trial. Participants will be assigned to received either a daily dose of fish oil capsules containing 1290 mg DHA or placebo (corn oil) administered as three capsules taken before bedtime. Their cognitive function will be measured using standardized computer and verbal test before at the mid point and the end of the trial. The tests used are the Standardise Mini Mental State examination ( SMMSE), California Verbal Learning Test – second edition (CVLT-II) and the Computerised Test of Information Processing (CTIP). Weight, heigh and waist circumference will be taken using standard methods. A blood sample will be taken at baseline, midpoint and end of the trial to measure inflammation and compliance with treatment. Capsules will be provided at the start of the trial and at the midpoint with all unconsumed capsules needing to be returned. Each visit is anticipated to take approximately 60 mins. There are 3 visits in total.

The screening and intervention will be conducted by a clinical Dietitian who is trained in anthropometric techniques and dietary analysis and who has additional training in conducing the cognitive tests. The blood samples will be taken by a research team member who has training in blood collection and first aid.
Intervention code [1] 293797 0
Treatment: Other
Comparator / control treatment
The control treatment/ placebo is corn oil. Capsules will be identical in size and shape to treatment fish oil capsules
Control group

Primary outcome [1] 297219 0
Change in cognitive test scores ( Standardised Mini Mental State Examination ( SMMSE), California Verbal Learning Test- second edition ( CVLT-II), computerised test of information processing, (CTIP) )
Timepoint [1] 297219 0
From baseline, 3 months and 6 months after commencement of intervention.
Primary outcome [2] 297220 0
Change in Inflammatory cytokines ( Il-6, IL-1b, TNF-a, CRP) as measured in blood sample
Timepoint [2] 297220 0
From baseline, 3 months and 6 months after commencement of intervention.
Primary outcome [3] 297221 0
Change in Oxidative stress ( F2 Isoprostane) as measured in blood sample
Timepoint [3] 297221 0
From baseline, 3 months and 6 months after commencement of intervention.
Secondary outcome [1] 320379 0
Change in blood lipids as measured in blood sample
Timepoint [1] 320379 0
From baseline, 3 months and 6 months after commencement of intervention.
Secondary outcome [2] 320380 0
change in erythrocyte DHA levels
Timepoint [2] 320380 0
From baseline, 3 months and 6 months after commencement of intervention.
Secondary outcome [3] 320465 0
Change in Hba1C as measured in blood sample
Timepoint [3] 320465 0
From baseline, 3 months and 6 months after commencement of intervention.

Key inclusion criteria
Diagnosed Type 2 diabetes ( diet controlled, taking oral hypoglycaemic agents or insulin)
Greater or equal to 50 years of ages
Not taking omega 3 supplements
Low habitual consumption of oily fish ( < 100g 3 times per week)
Fluent in English
Minimum age
50 Years
Maximum age
No limit
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
Less than 50 years of age
Clinically established history of psychiatric disorder including depression and substance/ alcohol abuse
Clinically established history of co-morbid neurological disorder liable to affect cognition, including dementia
Taking omega 3 supplements
High habitual consumption of oily fish ( > 100g 3 times per week)

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Central computer generated allocation
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Permuted block randomization
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?
The people receiving the treatment/s
The people administering the treatment/s
The people assessing the outcomes
The people analysing the results/data
Intervention assignment
Other design features
Not Applicable
Type of endpoint(s)
Statistical methods / analysis
The sample size calculations for this pilot study have been made by La Trobe University biostatistician, Dr. Mary Ann Davey. Based on a previous report of normative data for elderly participants undertaking cognitive testing (Paolo, et al. 2008), we have calculated that n=39 participants will be required in each treatment group to provide 80% power to detect a 6 point improvement in California Verbal Learning Test (CVLT) from 42.67 to 48.67 with SD of +/- 8.86. This allows for 10% drop out of participants between the control and intervention groups. Paolo and colleagues reported different scores for males and females. Therefore, we calculated an average of the mean and SD from males and females scores for the present study.

We will perform descriptive and comparison statistics (independent t test, 2-tailed) of baseline characteristics between the two treatment groups. Changes to cognitive domains and inflammatory biomarker status during the treatment period between DHA and placebo groups will be assessed using ANCOVA models to adjust for possible confounders and to also assess participant characteristics that may are beneficial (or disadvantageous) to DHA supplementation (eg. education, age, gender). While the primary focus is change at 6 months, the 3 month mid-point data will also be used in a repeated measures analysis to analysis change over time. Linear mixed effect (LME) models will be used for this analysis to account for correlation over time within participants.

Recruitment status
Not yet recruiting
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment in Australia
Recruitment state(s)
Recruitment postcode(s) [1] 12688 0
3086 - La Trobe University

Funding & Sponsors
Funding source category [1] 292807 0
Name [1] 292807 0
La Trobe University
Address [1] 292807 0
Kingsbury Drive
Bundoora Victoria 3086
Country [1] 292807 0
Primary sponsor type
La Trobe Univeristy
Kingsbury Drive
Bundoora Victoria 3086
Secondary sponsor category [1] 291545 0
Commercial sector/Industry
Name [1] 291545 0
FMC Health and Nutrition
Address [1] 291545 0
Industriveien 33,
NO - 1337 Sandvika
Country [1] 291545 0
Other collaborator category [1] 278798 0
Name [1] 278798 0
University of Newcastle
Address [1] 278798 0
University Dr, Callaghan NSW 2308
Country [1] 278798 0
Other collaborator category [2] 278799 0
Name [2] 278799 0
Royal Melbourne Hospital
Address [2] 278799 0
Grattan Street Parkville Victoria 3050
Country [2] 278799 0

Ethics approval
Ethics application status
Submitted, not yet approved
Ethics committee name [1] 294307 0
University Human Ethics Committee
Ethics committee address [1] 294307 0
Latrobe University
Kingsbury Dr
Bundoora Victoria 3086
Ethics committee country [1] 294307 0
Date submitted for ethics approval [1] 294307 0
Approval date [1] 294307 0
Ethics approval number [1] 294307 0

Brief summary
Type 2 diabetes is linked with many complications such as heart disease, eye disease and kidney disease. People with Type 2 diabetes also have higher rates of diseases of the nervous system in the body including dementia and may have poorer memory and thinking ability compared to people without Type 2 Diabetes. Older people with Type 2 Diabetes are at higher risk for poorer brain function.

Diet plays an important role in mental well-being and brain function as the brain needs nutrients found in foods to function well. Omega 3 fatty acids such as those found in fish oils, are found in the brain tissue in large amounts. Increasing dietary intake of fish oils can increase the amount of fish oils in the brain.

The aim of this study is to determine if an increase in dietary fish oils can improve the function of the brain in older people with Type 2 diabetes. This pilot study will fill a gap as it is not known if an increase in dietary Omega 3 fatty acids can improve brain function in older people with type 2 diabetes. This is important as the number of older people with diabetes is increasing and currently there are no effective treatments for poor brain function.

Eligible volunteers who participate in the study will be given a 6 month supply of fish oil or placebo capsules to take daily. Mental function will be measure by a verbal and computerized tests at the beginning, middle and end of the trial. A blood test, height, weight, and waist circumference will also be collected as well as information about the food you eat and drink at the beginning middle and end of the study. Neither you or the clinician conducting the research will know if you receive the fish oil or the placebo treatment, but a confidential record of which treatment you received will be kept by the chief investigator in the unlikely event you have an adverse reaction.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 63238 0
A/Prof Catherine Itsiopoulos
Address 63238 0
School of Allied Health College of Science, Health and Engineering
La Trobe University Bundoora Victoria 3086 AUSTRALIA

Country 63238 0
Phone 63238 0
+61 (0) 3 9479 1721
Fax 63238 0
+61 (0) 3 9479 2507
Email 63238 0
Contact person for public queries
Name 63239 0
Ms Andrea Bramley
Address 63239 0
School of Allied Health College of Science, Health and Engineering
La Trobe University Bundoora Victoria 3086 AUSTRALIA
Health Sciences Building 3 Room 345
Country 63239 0
Phone 63239 0
+61 (0) 3 9479 2283
Fax 63239 0
+61 (0) 3 9479 5768
Email 63239 0
Contact person for scientific queries
Name 63240 0
A/Prof Catherine Itsiopoulos
Address 63240 0
School of Allied Health College of Science, Health and Engineering
La Trobe University Bundoora Victoria 3086 AUSTRALIA
Country 63240 0
Phone 63240 0
+61 (0) 3 9479 1721
Fax 63240 0
+61 (0) 3 9479 2507
Email 63240 0

No information has been provided regarding IPD availability
Summary results
No Results