Omega-3 fatty acids and brain resistance to ageing and stress: body of evidence and possible mechanisms
Ageing Research Reviews. 2013-03-01; 12(2): 579-594
DOI: 10.1016/j.arr.2013.01.007
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Denis I(1), Potier B, Vancassel S, Heberden C, Lavialle M.
Author information:
(1)INRA UR909 Unité de Nutrition et Régulations Lipidiques des Fonctions
Cérébrales, 78352 Jouy-en-Josas cedex, France.
The increasing life expectancy in the populations of rich countries raises the
pressing question of how the elderly can maintain their cognitive function.
Cognitive decline is characterised by the loss of short-term memory due to a
progressive impairment of the underlying brain cell processes. Age-related brain
damage has many causes, some of which may be influenced by diet. An optimal diet
may therefore be a practical way of delaying the onset of age-related cognitive
decline. Nutritional investigations indicate that the ω-3 poyunsaturated fatty
acid (PUFA) content of western diets is too low to provide the brain with an
optimal supply of docosahexaenoic acid (DHA), the main ω-3 PUFA in cell
membranes. Insufficient brain DHA has been associated with memory impairment,
emotional disturbances and altered brain processes in rodents. Human studies
suggest that an adequate dietary intake of ω-3 PUFA can slow the age-related
cognitive decline and may also protect against the risk of senile dementia.
However, despite the many studies in this domain, the beneficial impact of ω-3
PUFA on brain function has only recently been linked to specific mechanisms.
This review examines the hypothesis that an optimal brain DHA status, conferred
by an adequate ω-3 PUFA intake, limits age-related brain damage by optimizing
endogenous brain repair mechanisms. Our analysis of the abundant literature
indicates that an adequate amount of DHA in the brain may limit the impact of
stress, an important age-aggravating factor, and influences the neuronal and
astroglial functions that govern and protect synaptic transmission. This
transmission, particularly glutamatergic neurotransmission in the hippocampus,
underlies memory formation. The brain DHA status also influences neurogenesis,
nested in the hippocampus, which helps maintain cognitive function throughout
life. Although there are still gaps in our knowledge of the way ω-3 PUFA act,
the mechanistic studies reviewed here indicate that ω-3 PUFA may be a promising
tool for preventing age-related brain deterioration.
Copyright © 2013 Elsevier B.V. All rights reserved.