Neurons are greedy! High metabolism makes them heavy users of energy and nutrients compared to cells in the rest of the body (bone cells, blood cells, kidney cells etc). The adequacy and efficiency by which neurons are provided with their required building blocks influence how they function, how they resist brain damage and how they recovery from injury. Docosahexaenoic acid (DHA) omega-3 fatty acid, found mainly in fish, is one of those building blocks crucial for maintenance of healthy cell membranes. Why is that important? At the cell membrane, DHA is important for the function of synapses; the connections between nerve cells at the ends of their branches (called dendrites). Read my previous post ‘Neuroplasticity is all about chemicals and synapses’ for some background. These synapses are special communication machines that transport chemicals from the membrane of one neuron to the membrane of the neighbouring neuron. Chemical communication at synapses is important for our every thought, memory and action and dependent on adequate DHA. DHA is also known to activate neurotrophins BDNF and IGF-I (see my post on ‘Neurotrophins are brain fertilizers’ for a refresher) which help to facilitate synaptic transmission. In one study by Wu at UCLA published in 2004 in the Journal of Neurotrauma, rats supplemented with DHA after a traumatic brain injury had less tissue damage and better ability to learn. Several studies have shown that DHA supplementation improves children’s academic performance (Richardson Pediatrics 2005, Osendarp Am J Clinical Nutrition 2007).
Humans do not efficiently make their own DHA so it must be obtained from food. No-one knows if eating DHA-rich foods or supplementation with DHA is beneficial for recovery after brain injury. This research has not been done …YET! We also don’t know the optimum ‘dosage’ of DHA. However it would seem reasonable that a person after brain injury requires DHA in order to build new synaptic networks. People with brain injury should take special care that they are eating foods that contain DHA such as salmon, tuna, mackerel, cod and sardines. For those squeamish about fish, there are non-fish sources of DHA like flaxseed, canola oil, and omega-3 eggs.