Accumulation of Dietary Docosahexaenoic Acid in the Brain Attenuates Acute Immune Response and Development of Postischemic Neuronal Damage – Source: Stroke, Aug 18, 2011
By Hebert M Lalancette, et al.
[Note: Ischemic stroke involves blockage that interrupts blood supply to part of the brain. For more recent research on this subject, see “Fish oil DHA within 5 hours after stroke may limit & even repair some brain damage - LSU research discovery.”]
Background and Purpose: Consumption of fish has been shown to reduce risk of coronary heart disease and, possibly, of ischemic stroke.
Because docosahexaenoic acid (DHA) is the most likely neuroactive component within fish oil, we hypothesized that exposing mice to a DHA-enriched diet may reduce inflammation and protect neurons against ischemic injury.
Methods: To visualize the effects of DHA on neuroinflammation after stroke, TLR2-fluc-GFP transgenic mice were exposed to either a control diet, a diet depleted in omega-3 polyunsaturated fatty acid, or a diet enriched in DHA during 3 months.
Real-time biophotonic/bioluminescence imaging of the TLR2 response was performed before and after middle cerebral artery occlusion, whereas cytokines concentrations and stroke area analyses were performed at 3 and 7 days after middle cerebral artery occlusion, respectively.
Results: We show that:
• A 3-month DHA treatment prevented microglial activation after ischemic injury, [microglia are thought to contribute to ischemic stroke damage by inducing inflammatory response]
• Reduced the ischemic lesion [damage] size,
• And increased levels of the antiapoptotic molecule Bcl-2 in the brain [apoptosis is cell death].
• Additional analysis revealed a significant decrease in the levels of COX2 and IL-1beta, but not in other proinflammatory cytokines.
• Importantly, long-term DHA supplementation significantly changed the omega-3 to omega-6 polyunsaturated fatty acid ratio in the brain [an imbalance toward too much omega-6 is considered proinflammatory].
• Collectively, these data indicate that diet-induced accumulation of DHA in the brain protects against post-ischemic inflammation and injury.
• Because DHA is widely available at low cost and has an excellent safety profile, our data suggest that increased DHA intake may provide protection against acute immune response/brain damage in ischemic stroke.
Source: Stroke, Aug 18, 2011. PMID: 21852616, by Lalancette-Hébert M, Julien C, Cordeau P, Bohacek I, Weng YC, Calon F, Kriz J. Croatian Institute for Brain Research, Zagreb University Medical School, Zagreb, Croatia; Department of Psychiatry and Neuroscience, Faculty of Medicine, Faculty of Pharmacy, Université Laval, Laval University, CHUQ Research Center-Laval University, Québec, Canada. [Email: firstname.lastname@example.org]