Researchers from the UCLA School of Medicine in Los Angeles said omega-3 fatty acids crossed over into the central nervous system, where it reduced the “excitability” of brain cells that prompted seizures.
Its authors said: "Low dose fish oil is a safe and low cost intervention that may reduce seizures and improve cardiovascular health in people with epilepsy."
People with epilepsy have a significantly greater risk of heart attack than those without the condition.
The trials saw 24 people with drug resistant epilepsy receiving three 10-week treatments of high dose, low dose and placebo, with two six-week “washout periods” in between.
The low-dose treatment consisted of three capsules of fish oil daily equivalent to 1080mg of omega-3 as well as three capsules of placebo corn oil, while the high dose was six capsules of fish oil daily equivalent to 2160mg. The placebo treatment was three capsules of corn oil twice a day.
During the low-dose treatment, the average seizure frequency was 12 a month. For the high-dose treatment this averaged 17, while the placebo group had an average of 18. Researchers said the results worked out at a 33.6% lower seizure frequency compared to the placebo.
Two of participants did not have any seizures during their ten-week period of taking the lower dosage, while no one taking the high dose or the placebo was seizure free.
The researchers said the low dose was also associated with a modest fall in blood pressure of 1.95 mm Hg (millimetres of mercury) over the ten-week period. Yet the high dose fish oil was associated with an average increase of 1.84 mm Hg.
However they stressed while these initial results may suggest a link to seizure frequency for low doses, neither dose had an impact on heart rate, blood fat levels or severity of the seizures.
One of the participants died during the high-dose treatment period, something an autopsy confirmed as sudden death in epilepsy (SUDEP). The participant was also taking multiple antiepileptic drugs and aripiprazole, an antipsychotic the researchers said had been associated with an increase in cardiac mortality.
“The patient had failed epilepsy surgery, vagal nerve stimulation, had frequent tonic–clonic seizures and was found after a seizure next to his bed in the prone position. The cause of death was thought by the investigator to be unrelated to the treatment with fish oil,” the researchers said.
Source: Journal of Neurology, Neurosurgery, and Psychiatry
Published online ahead of print, doi:10.1136/jnnp-2014-307749
“Fish oil (n-3 fatty acids) in drug resistant epilepsy: a randomised placebo-controlled crossover study”
Authors: C. M. DeGiorgio, P. R. Miller, R. Harper, J. Gornbein, L. Schrader, J. Soss, S. Meymandi