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.
- Dangour AD, Allen E, Elbourne D, Fasey N, Fletcher AE, Hardy P, Holder GE, Knight R, Letley L, Richards M, Uauy R (2010) Effect of 2-y n-3 long-chain polyunsaturated fatty acid supplementation on cognitive function in older people: a randomized, double-blind, controlled trial. Am J Clin Nutr 91:1725–1732PubMedCrossRefGoogle Scholar
- Fagherazzi EV, Garcia VA, Maurmann N, Bervanger T, Halmenschlager LH, Busato SB, Hallak JE, Zuardi AW, Crippa JA, Schröder N (2012) Memory-rescuing effects of cannabidiol in an animal model of cognitive impairment relevant to neurodegenerative disorders. Psychopharmacology 219:1133–1140PubMedCrossRefGoogle Scholar
- Freund-Levi Y, Eriksdotter-Jonhagen M, Cederholm T, Basun H, Faxén-Irving G, Garlind A, Vedin I, Vessby B, Wahlund L-O, Palmblad J (2006) Omega-3 fatty acid treatment in 174 patients with mild to moderate Alzheimer disease: omegAD study: a randomized double-blind trial. Arch Neurol 63:1402–1408PubMedCrossRefGoogle Scholar
- Lee LK, Shahar S, Rajab N, Mohd Yusoff NA, Jamal RA, Then SM (2012b) The role of long chain omega-3 polyunsaturated fatty acids in reducing lipid peroxidation among elderly patients with mild cognitive impairment: a case–control study. J Nutr Biochem. doi: 10.1016/j.jnutbio.2012.04.014
- Ng TP, Gao Q, Niti M, Feng L, Yap KB (2011) Omega-3 polyunsaturated fatty acid supplements and cognitive decline: Singapore longitudinal aging studies. JNHA 15:32–35Google Scholar
- Petersen RC (2007) Mild cognitive impairment. Continuum Lifelong Learning Neurol 13:15–38Google Scholar
- Rey A (1964) L’examen clinique en psychologie. In: Presses Universitaires de France. Paris (in French)Google Scholar
- Shinto L, Quinn J, Montine T, Baldauf-Wagner SB, Bourdette D, Oken DB, Kaye J (2008) Omega-3 fatty acids and lipoic acid in Alzheimer’s disease. Neurology 70:A393Google Scholar
- Sinn N, Milte CM, Street SJ, Buckley JD, Coates AM, Petkov J, Howe PRC (2012) Effects of n−3 fatty acids, EPA v. DHA, on depressive symptoms, quality of life, memory and executive function in older adults with mild cognitive impairment: a 6-month randomised controlled trial. Br J Nutr 107:1682–1693PubMedCrossRefGoogle Scholar
- Sonobe N, Hata R, Ishikawa T, Sonobe T, Matsumoto T, Toyota Y, Mori T, Fukuhara R, Komori K, Ueno SI, Tanimukai S, Ikeda M (2011) Risk of progression from mild memory impairment to clinically diagnosable Alzheimer’s disease in a Japanese community (from the Nakayama Study). Int Psychogeriatr 23:772–779CrossRefGoogle Scholar
- Wechsler D (1984) Wechsler memory scale—revised manual. The Psychological Co, New YorkGoogle Scholar
- Wechsler D (1997) Wechsler adult intelligence scale. Harcourt Assessment, LondonGoogle Scholar