Docosahexaenoic acid-concentrated fish oil supplementation in subjects with mild cognitive impairment (MCI): a 12-month randomised, double-blind, placebo-controlled trial
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Epidemiological studies have suggested a beneficial effect of fish oil supplementation in halting the initial progression of Alzheimer’s disease. However, it remains unclear whether fish oil affects cognitive function in older people with mild cognitive impairment (MCI).
This study investigated the effects of fish oil supplementation on cognitive function in elderly person with MCI.
This was a 12-month, randomised, double-blind, placebo-controlled study using fish oil supplementation with concentrated docosahexaenoic acid (DHA). Thirty six low-socioeconomic-status elderly subjects with MCI were randomly assigned to receive either concentrated DHA fish oil (n = 18) or placebo (n = 18) capsules. The changes of memory, psychomotor speed, executive function and attention, and visual-constructive skills were assessed using cognitive tests. Secondary outcomes were safety and tolerability of the DHA concentrate.
The fish oil group showed significant improvement in short-term and working memory (F = 9.890; ηp 2 = 0.254; p < 0.0001), immediate verbal memory (F = 3.715; ηp 2 = 0.114; p < 0.05) and delayed recall capability (F = 3.986; ηp 2 = 0.121; p < 0.05). The 12-month change in memory (p < 0.01) was significantly better in the fish oil group. Fish oil consumption was well tolerated, and the side effects were minimal and self-limiting.
This study suggested the potential role of fish oil to improve memory function in MCI subjects. Studies with larger sample sizes, longer intervention periods, different fish oil dosages and genetic determinations should be investigated before definite recommendations can be made.
KeywordsFish oil Mild cognitive impairment Docosahexaenoic acid Cognitive function Memory
Cognitive section of the AD Assessment Scale
Analysis of covariance
Clock drawing test
Geriatric depression scale
Mild cognitive impairment
Mini-mental state examination
Polyunsaturated fatty acids
Rey Auditory Verbal Learning Test
This work was supported by the Research University (grant number UKM-GUP-SK-07-21-041) grant scheme from the Universiti Kebangsaan Malaysia.
Both the fish oil and placebo capsules were provided by the EPAX AS, Lysaker, Norway. The authors have no conflicts of interest.
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