EPA and DHA needed for optimal nervous system function

A report appearing in the December 2009 issue of the American Psychological Association journal Behavioral Neuroscience...........................
http://www.apa.org/pubs/journals/bne/

..............revealed that diets that fail to provide enough of the omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) may negatively affect the nervous system. The finding could impact the understanding of information-processing deficits that occur in schizophrenia, bipolar disease, obsessive-compulsive disorder, attention deficit-hyperactivity disorder (ADHD), Huntington's disease and other nervous system disorders.

Norman Salem Jr, PhD of the Laboratory of Membrane Biochemistry and Biophysics at the National Institute on Alcohol Abuse and Alcoholism and his associates gave one of the four following diets to pregnant mice and their offspring: omega-3 fatty acid deficient, low alpha-linolenic acid, high alpha-linolenic acid, or a diet enriched with EPA and DHA. DHA is the primary omega-3 fatty acid in the nervous system, including the brain. While DHA is metabolized from alpha-linolenic acid in the diet, the conversion is minimal, rendering a dietary source of DHA and EPA, such as fish oil or an algae source, of vital importance. "Humans can convert less than one percent of the precursor into DHA, making DHA an essential nutrient in the human diet," coauthor Irina Fedorova, PhD noted.

Adult offspring of the mice in the four groups were tested for nervous system function by exposing them to a loud noise preceded by a softer warning tone. Animals normally flinch upon hearing a loud tone, however, the degree of flinching is reduced when the animals are first exposed to a warning tone: an adaptive process known as sensorimotor gating. Weak sensorimotor gating in humans is associated with a number of nervous-system disorders.

While mice that were raised on EPA and DHA demonstrated normal sensorimotor gating, animals given the other diets were more startled by the loud noise. The finding suggests that a sensory overload state could result from DHA deficiency.

The ability of DHA and EPA to help maintain nerve cell membranes may be responsible for the protective effects observed in the current study. "It is an uphill battle now to reverse the message that 'fats are bad,' and to increase omega-3 fats in our diet," Dr Salem commented. "It only takes a small decrement in brain DHA to produce losses in brain function.".......................
http://www.lef.org/newsletter/2009/1222_EPA-and-DHA-Needed-for-Optimal-Nervou...