Omega-3 fatty acids DHA reduce stroke damage
Stroke: Reduced Risks with Omega 3 Fatty Acids
The benefits of the omega-3 fatty acid DHA (docosahexaenoic acid) against stroke have been confirmed. According to a study from Université Laval in Ville de Québec (Canada), this fatty acid can reduce damage from this cerebral event by 25%.
The news comes from the journal Stroke, where the authors specify that the consumption of omega-3 DHA creates in the brain anti-inflammatory and neuroprotective conditions that counteract the damage caused by stroke. In this way, explains Jasna Kriz, the study coordinator, omega-3s prevent the acute inflammatory response that would follow the event, which is very dangerous for nervous tissue.
Modulation of the Immune Response
The researchers reached these conclusions using genetically predisposed mice to develop stroke as the model organism. The animals were divided into three groups, each fed with different amounts of DHA. While control mice received a DHA-free diet, a second group received low doses of the Omega-3 fatty acid. The remaining mice received about 0.7 grams of DHA per kilogram of body weight daily, corresponding to a massive dose of Omega-3. After three months, mice in the third group showed reduced levels of compounds that stimulate inflammation.
These include COX2, one of the proteins responsible for prostaglandin production — factors involved in inflammatory processes — and interleukin-1beta (IL-1beta), a molecule that promotes inflammation — for example during bacterial infections — promotes prostaglandin synthesis, and stimulates immune system activation. Besides lowering molecules that induce inflammation, the intake of DHA led to an increase in factors that counteract cell death activation. Furthermore, administration of high doses of DHA also increased the ratio between Omega-3 and Omega-6 fatty acids. Specifically, the Omega-3 fatty acid partially replaces another molecule, arachidonic acid, an omega-6 fatty acid known for its capacity to induce inflammation.
Omega-3 Benefits for the Brain
According to the researchers, this is the first convincing demonstration of the powerful anti-inflammatory action exerted by DHA in the brain. Translated to humans, it would indicate that 42 grams of DHA is the amount of Omega-3 a 60 kg man should consume daily to achieve the same effects observed in mice by the Canadian researchers. However, Frédéric Calon, co-author of the study, explained that mice have a faster metabolism than humans and, considering the 2,000 calories consumed on average by an adult, these 42 grams could be reduced to 2.5–3 grams of DHA or EPA (eicosapentaenoic acid, another important Omega-3) per day.
Source:
1. Lalancette-Hébert M, Julien C, Cordeau P, Bohacek I, Weng YC, Calon F, Kriz J, “Accumulation of Dietary Docosahexaenoic Acid in the Brain Attenuates Acute Immune Response and Development of Postischemic Neuronal Damage”, Stroke. 2011 Aug 18. [Epub ahead of print]
