Abstract
The maintenance of optimal cognitive function is a central feature of healthy aging.
Impairment in brain glucose uptake is common in aging associated cognitive deterioration,
but little is known of how this problem arises or whether it can be corrected or bypassed.
Several aspects of the challenge to providing the brain with an adequate supply of
fuel during aging seem to relate to omega-3 fatty acids. For instance, low intake
of omega-3 fatty acids, especially docosahexaenoic acid (DHA), is becoming increasingly
associated with several forms of cognitive decline in the elderly, particularly Alzheimer's
disease. Brain DHA level seems to be an important regulator of brain glucose uptake,
possibly by affecting the activity of some but not all the glucose transporters. DHA
synthesis from either α-linolenic acid (ALA) or eicosapentaenoic acid (EPA) is very low in humans begging
the question of whether these DHA precursors are likely to be helpful in maintaining
cognition during aging. We speculate that ALA and EPA may well have useful supporting
roles in maintaining brain function during aging but not by their conversion to DHA.
ALA is an efficient ketogenic fatty acid, while EPA promotes fatty acid oxidation.
By helping to produce ketone bodies, the effects of ALA and EPA could well be useful
in strategies intended to use ketones to bypass problems of impaired glucose access
to the brain during aging. Hence, it may be time to consider whether the main omega-3
fatty acids have distinct but complementary roles in brain function.
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Published online: July 10, 2006
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© 2006 Elsevier Ltd. Published by Elsevier Inc. All rights reserved.
