People with uncontrolled epilepsy have low levels of a certain fatty acid

Omega-3 fatty acids are crucial to the proper development and function of cell membranes in the brain. But one particular fatty acid, docosahexaenoic acid (DHA), is found at abnormally low levels in patients with uncontrolled epilepsy, according to researchers at Emory University in Atlanta, GA.

The study was based on 41 persons with refractory complex partial seizures (a common type of seizure that develops in one brain region and is resistant to antiepileptic medication) when compared to a control group of 57 healthy persons. The results of the study will be presented at the American Academy of Neurology in San Francisco, CA, on Wednesday, April 28 at 8 p.m. Eastern.

DHA is essential for the development of the nervous system and visual abilities in babies and for the proper functioning of the brain in adults. The human body cannot produce sufficient amounts of DHA for the needs of the eye and brain. Therefore, DHA must be consumed though foods, such as cold water fatty fish, or in supplemental form.

"We looked at prior studies of animal models of rats with epilepsy and low levels of DHA," says Thomas R. Henry, MD, associate professor of neurology, Emory University School of Medicine and director of the Emory Epilepsy Center. "By giving these rats more DHA, it made it more difficult for them to have seizures. We are now exploring a similar connection of low DHA levels in humans who have epilepsy."

Forty-one people with refractory complex partial seizures enrolled in this study, which was funded by the Emory University Research Committee. They all had blood drawn and analyzed for levels of DHA. Fifty-seven healthy volunteers, which served as the control group, also had their blood drawn and analyzed. The range in age and gender was similar in both groups.

After complete analyses, researchers found significantly lower levels of DHA in the red blood cell membranes of the group with uncontrolled epilepsy (mean erythrocyte membrane DHA level of 2.74%) when compared to DHA levels in the healthy group (epilepsy (mean erythrocyte membrane DHA level of 3.46%). This implies the brain also has low membrane levels of DHA in neuronal membranes. (A prior study showed that low DHA levels in red blood cell membranes correlates with low membrane levels of DHA in cerebral neurons.)

"By determining a deficiency in the red blood cell membranes in these patients, we infer that brain cell membranes are also depleted of this normal fatty acid," says Dr. Henry. "This may help us link low DHA to seizures which cannot be managed by antiepileptic medications. Reasons for the reduced membrane levels are unclear at this time. Future studies are needed to determine if DHA supplementation can help control seizures in this patient population."