The OPAL Study: Older People And n-3 Long-chain polyunsaturated fatty acids

Status

Active, not recruiting

Phases

Unknown

Study type

Interventional

Source

ISRCTN

Registry ID

ISRCTN72331636

Enrollment

800

Registered

2004-07-14

Start date

2004-03-01

Completion date

Unknown

Last updated

2015-01-13

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Cognitive and retinal function Eye Diseases Cognitive and retinal function

Interventions

Daily nutritional supplement of 0.7 g of n-3 long chain polyunsaturated fatty acids (fish oil) versus placebo. The main outcome variable assessed at 24 months will be cognitive performance and a secon

Eligibility

Inclusion criteria

Inclusion criteria: Healthy volunteers aged between 70-79 years of age, who have no previous history of diabetes or dementia. Participants will be selected from 20 GP practices.

Exclusion criteria

Exclusion criteria: 1. Pre-existing type I or type II diabetes at baseline 2. Pre-existing dementia at baseline 3. Reported daily use of fish-oil supplements (in liquid or capsule form) at baseline 4. Mini-mental state examination (MMSE) score <24 at baseline screen

Design outcomes

Primary

Measure	Time frame
1. Change in cognitive function at 24 months determined by the California Verbal Learning Test 2. Change in rod sensitivity over 24 months of intervention as measured by electroretinogram	—

Secondary

Measure	Time frame
1. Cognitive performance as measured by immediate and delayed recall of a short story, tests of prospective memory, timed letter search/cancellation task, verbal fluency, digit span backwards, symbol digit modalities test, simple and choice reaction time, dual-task performance and spatial memory 2. Blood pressure 3. Measure of depression 4. Change in Body Mass Index 5. Compliance determined by counting the number of tablets remaining every 3 months, and by measuring the change in n-3 LCP concentration in buccal epithelial cells over 24 months 6. Number of hospital admissions for cardiovascular events over 24 months 7. Death 8. Colour vision measured by detecting sensitivity to colour contrast which is a good marker of central retinal function 9. Eye health assessed by carrying out a full ophthalmic examination	—

Measure

Time frame

1. Cognitive performance as measured by immediate and delayed recall of a short story, tests of prospective memory, timed letter search/cancellation task, verbal fluency, digit span backwards, symbol digit modalities test, simple and choice reaction time, dual-task performance and spatial memory 2. Blood pressure 3. Measure of depression 4. Change in Body Mass Index 5. Compliance determined by counting the number of tablets remaining every 3 months, and by measuring the change in n-3 LCP concentration in buccal epithelial cells over 24 months 6. Number of hospital admissions for cardiovascular events over 24 months 7. Death 8. Colour vision measured by detecting sensitivity to colour contrast which is a good marker of central retinal function 9. Eye health assessed by carrying out a full ophthalmic examination

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Countries

United Kingdom

Outcome results

None listed

Source: ISRCTN (via WHO ICTRP) · Data processed: Feb 4, 2026