Two years ago, a Dutch team studying older men reported that the subjects who ate more fish—and omega-3 fat—also displayed better mental functioning.
As they said, "A moderate intake of [omega-3] EPA+DHA may postpone cognitive decline in elderly men.”
But as they also wrote, "Results from other studies are needed before definite conclusions about this association can be drawn” (van Gelder BM et al. 2007).
We covered this study in "Mental Decline Slowed by Omega-3s”.
(You’ll find other relevant research summaries in "Omega-3s Linked to Seniors’ Brain Health and Longevity” and "Omega-3s Boost Aging Brains in Clinical Trial”. For a full roster of reports on related research, search our newsletter archives for "brain”.
As if in response, a British research team just published the positive results of an epidemiological study … findings that support those of the Dutch investigation and several others.
British study finds beneficial impacts
The UK team surveyed 867 participants aged 70 to 79 about their fish consumption, and administered mental tests to gauge their cognitive abilities, brain speed, attention, and psychological health.
To isolate the effects of eating fish, versus supplemental fish oil, only people who did not take fish oil supplements were included.
The researchers, led by Alan Dangour, Ph.D., of the University of London recorded significantly better scores among the people reported eating more fish.
Using the Californian Verbal Learning Test (CVLT) and others, they tested the participants’ memory, executive function, psychomotor speed, and attention.
Their analysis revealed significant positive associations between higher fish consumption and better CVLT scores with an average increase of approximately 0.24 words remembered for each increase in level of reported fish consumption.
These advantages were a bit weaker after adjusting the results to account for the effects of age, gender, education level, and mental health.
Similar associations were recorded between fish consumption and the participants’ scores on tests of cognitive ability, memory, executive functions, and more. Again, these associations were less strong after adjusting the results to account for the effects of age, gender, education level, and mental health.
As the authors concluded, these results "provide support for the hypothesis that higher fish consumption is associated with better cognitive function in later life (Dangour AD et al. 2009).
However, even though significant benefits remained after the results were adjusted to account for the benefits of education and better psychological health, they were not so strong as to rule out the possibility that socioeconomic status or other factors associated with greater fish consumption might be partly responsible.
Evidence from randomized clinical trial is needed to confirm the positive indications of this and numerous other epidemiological studies.
To help fill that gap, the same research team began just such a trial in 2006, among Brits in the same age range as this study.
We’ll keep our eyes peeled for the results of that investigation!
- Dangour AD, Allen E, Elbourne D, Fletcher A, Richards M, Uauy R. Fish Consumption and Cognitive Function among Older People in the UK: Baseline Data from the Opal Study. J Nutr Health Aging. 2009;13(3):198-202.
- Daniels JL, Longnecker MP, Rowland AS, Golding J; ALSPAC Study Team. University of Bristol Institute of Child Health. Fish intake during pregnancy and early cognitive development of offspring. Epidemiology. 2004 Jul;15(4):394-402.
- Kalmijn S, van Boxtel MP, Ocké M, Verschuren WM, Kromhout D, Launer LJ. Dietary intake of fatty acids and fish in relation to cognitive performance at middle age. Neurology. 2004 Jan 27;62(2):275-80.
- van Gelder BM, Tijhuis M, Kalmijn S, Kromhout D. Fish consumption, n-3 fatty acids, and subsequent 5-y cognitive decline in elderly men: the Zutphen Elderly Study. Am J Clin Nutr. 2007 Apr;85(4):1142-7.