From Ergo Log
Your brain absorbs new information better if you eat oily fish such as salmon or mackerel a couple of times a week, or take fish oil capsules. And this ability increases even more if you also get daily exercise, according to an animal study that psychologists at the University of California at Los Angeles published in Neuroscience.
The researchers gave some of the lab rats feed to which the fish fatty acid DHA had been added [DHA]. Another group of the animals were given standard feed [RD].
The researchers divided both groups of the rats into two subgroups. One subgroup was given a treadmill in the cage that the rats could use to run in as much as they wanted [Exc]. The other group had no access to fitness equipment, so got very little movement [Sed]. After a week the researchers tested the lab animals' learning capacity using the Morris Water Maze test.
The Morris Water Maze test consists of putting rats a number of times into an aquarium, where somewhere, just under the surface of the water, a platform is hidden. You then measure how long it takes for the animals to find the platform [Latency]. DHA supplementation resulted in a shorter amount of search time, and when combined with physical exercise the time was even less.
The increase in learning ability was probably the consequence of increased synthesis of BDNF. BDNF enables brain cells to grow and form new connections, so that the brain can absorb new information. DHA boosted the concentration of BDNF, and yes, this increase was larger when combined with exercise.
In the rats' brain cells there was a relationship between the activity of the anabolic molecule Akt and BDNF. The higher the concentration of BDNF, the greater the activity.
"The effects of diet and exercise on the brain are receiving increasing recognition, making us to ask what would be the combined effects of both, as it normally occurs under daily living conditions", the researchers write. "An unhealthy diet high in saturated fat has been shown to reduce the levels of BDNF-related synaptic plasticity and cognitive function, while the concurrent exposure to exercise compensated for the effects of the diet."
"Present studies indicate that exercise can boost the benefits of a healthy diet on neuroplasticity. These studies portray BDNF-mediated plasticity as a crucial intermediate mechanism for the effects of diet and lifestyle on the brain."
"The present results are significant to suggest that the inherent capacity of the brain to benefit from the effects of DHA dietary supplementation and exercise can be used to overcome neurological disorders affecting cognitive abilities."
Neuroscience. 2008 Aug 26;155(3):751-9.