The fatty acid present in fish reduces brain damage after an ischemic stroke if administered within five hours of the event, according to a rat study published in Translational Stroke Research.
Every year, 15 million people worldwide suffer a stroke, and 6 million die from it. It is the second cause of death in people over 60 and the main cause of long-term disability.
The majority of cases are ischemic stroke, i.e. when the artery that supplies the blood to the brain is blocked or not properly drained. The closure of an artery can be caused, for example, by a thrombus forming in the vessel wall on the basis of atherosclerotic plaque, or an embolism formed by fragments of thrombus brought with the bloodstream from the heart or larger vessels.
Researchers from the University of Louisiana in New Orleans tested the usefulness of the fish fat component in the treatment of stroke on rats. It is docosahexaenoic acid (DHA), which is one of the essential omega-3 unsaturated fatty acids. DHA is part of the membranes of nerve cells and is needed for the proper development of the nervous system, including the retina of the eye. It also takes part in the processes of remembering and in protecting the nervous tissue against harmful factors, such as free radicals released from cells damaged during a stroke.
Research suggests that because of its anti-inflammatory effects, DHA helps people with cardiovascular disease, asthma, rheumatoid arthritis, cancer, and many other chronic conditions. This compound is a natural component of our diet, and its main source is oily sea fish such as salmon, tuna, mackerel, sardines, herring and seafood.
In the most recent experiments, rats were administered DHA intravenously 3, 4, 5 and 6 hours after the experimentally induced ischemic stroke. The control group received saline (placebo) 3 hours after the stroke. A day later, and then after 2, 3 and 7 days, the rodents underwent tests assessing the effectiveness of the treatment.
Therapy with DHA was found to reduce neurological disorders, even when the compound was administered 5 hours after the stroke. Compared to the control group, the area of the brain damaged by stroke was on average 40 percent smaller. when DHA was given 3 hours after the event and by 66 percent. and 59% when given after 4 and 5 hours, respectively. The compound also limited brain swelling and stimulated the production of a natural molecule, the so-called D1 neuroprotectin (NPD1), which protects nerve tissue cells from damage. Magnetic resonance imaging studies showed that by administering DHA, nerve tissue in many areas of the brain did not differ from that of non-stroke rats after 7 days.
Currently, the most effective method of treating ischemic stroke is the intravenous administration of a thrombolytic drug that dissolves the clot and allows the blood supply to the nerve tissue to be restored as quickly as possible. However, for the therapy to work, the drug must be administered quickly – up to 4,5 hours after the stroke occurs, because the nervous tissue is very sensitive to the lack of nutrients (glucose) and oxygen and begins to die quickly. After this period, the restoration of blood circulation in the nerve tissue closest to the stroke focus (the so-called prenumbra or shadow zone) may damage it further due to the influx of various compounds, including free radicals released from dead cells.
Due to the time constraint, few people may benefit from thrombolytic treatment – less than 10%. – patients. Any increase in the length of time during which a larger area of the brain can be saved is of utmost importance.
We are just beginning to understand the significant effects of omega-3s on nervous tissue after stroke. We do not have a simple solution yet, but each new discovery brings us closer to better combating its effects and the effects of other diseases that damage the nervous tissue – comments Dr. Nicolas Bazan, who leads the research. (PAP)