Effects of krill oil containing n-3 polyunsaturated fatty acids in phospholipid form on human brain function: a randomized controlled trial in healthy elderly volunteers.
BACKGROUND
Krill oil, rich in n-3 (omega-3) polyunsaturated fatty acids (PUFAs) incorporated in phosphatidylcholine, has been reported to have many effects on physiological function. However, there are few studies using psychophysiological methods published that describe the effects of krill oil on brain function. We investigated the influence of ingestion of krill oil on cognitive function in elderly subjects by using near-infrared spectroscopy and electroencephalography.


METHODS
A randomized, double-blind, parallel-group comparative study design was adopted. Forty-five healthy elderly males aged 61-72 years were assigned to receive 12 weeks of treatment with: medium-chain triglycerides as placebo; krill oil, which is rich in n-3 PUFAs incorporated in phosphatidylcholine; or sardine oil, which is abundant in n-3 PUFAs incorporated in triglycerides. Changes in oxyhemoglobin concentrations in the cerebral cortex during memory and calculation tasks were measured. The P300 component of event-related potentials was also measured during a working memory task.


RESULTS
During the working memory task, changes in oxyhemoglobin concentrations in the krill oil and sardine oil groups were significantly greater than those in the medium-chain triglyceride group at week 12. The differential value for P300 latency in the krill oil group was significantly lower than that in the medium-chain triglyceride group at week 12. With regard to the calculation task, changes in oxyhemoglobin concentrations in the krill oil group were significantly greater than those in the medium-chain triglyceride group at week 12.


CONCLUSION
This study provides evidence that n-3 PUFAs activate cognitive function in the elderly. This is especially the case with krill oil, in which the majority of n-3 PUFAs are incorporated into phosphatidylcholine, causing it to be more effective than sardine oil, in which n-3 PUFAs are present as triglycerides.
['Konagai|Chizuru|C|', 'Yanagimoto|Kenichi|K|', 'Hayamizu|Kohsuke|K|', 'Han|Li|L|', 'Tsuji|Tomoko|T|', 'Koga|Yoshihiko|Y|']
D000368:Aged D000818:Animals D001921:Brain D019587:Dietary Supplements D004311:Double-Blind Method D033201:Euphausiacea D015525:Fatty Acids, Omega-3 D005260:Female D005399:Fishes D006801:Humans D007564:Japan D008297:Male D008568:Memory D008875:Middle Aged D010108:Oxyhemoglobins D012758:Shellfish
phosphatidylcholine near-infrared spectroscopy event-related potential docosahexaenoic acid dorsolateral prefrontal cortex eicosapentaenoic acid