Diets rich in fish and vegetable oils could reduce epileptic seizures

18 Aug 2017 --- For the first time, production of estrogen in the brain has been directly linked to a study to the presence of docosahexaenoic acid (DHA). The findings of a Hiroshima University study could have implications for treating seizures, as it links DHA directly to a reduction in epileptic seizures.

DHA is found in abundance in fish oils and is also synthesized from alpha-linolenic acid, an omega 3 fatty acid found in some vegetable-based oils. It has been linked in the past to healthy pregnancy.

The latest research from Hiroshima University connects DHA synthesis to estrogen production, and consequentially brain health. It further reinforces both estrogen’s role in brain health and the old advice that a daily intake of fish oil is good for you.

DHA and estrogen connected
Assistant Professor Yasuhiro Ishihara, from HU's Laboratory of Molecular Brain Science, wanted to determine if there was any link between estrogen synthesis and estrogen production. He is said to have been keenly aware of both the growing understanding of estrogen's role in brain health and DHA's ability to reduce epileptic seizures.

His research – recently published in Scientific Reports, and involving collaborators from Japan and the USA – investigated how three groups of mice fed on different oil based diets reacted to induced seizures.

One group was fed a diet consisting of soybean oil, another on cottonseed oil and a third on cottonseed oil in addition to DHA supplements.

These two oils used were chosen due to the differing yields of DHA obtained from them, as the body produces more DHA from soybean oil than cottonseed oil. The mice in the third group were also fed on cottonseed oil, but also crucially along with DHA supplements.

After 28 days on these diets, the three groups were exposed to seizure-inducing drugs. The group fed on soybean oil took longer to exhibit seizures, and when they did occur they were of a shorter duration than those fed on cottonseed oil.

However, the mice fed on cottonseed oil with DHA supplementation took far longer for seizures to take hold – proving that dietary sourced DHA was a key contributing factor.

When the researchers examined the brains of these mice they found that the soybean oil-fed ones had over twice the concentration of estrogen present as those fed solely on cottonseed oil. The mice fed on cottonseed with DHA supplementation had even higher levels of the hormone, suggesting that estrogen production affects seizures and that this is directly connected to the presence of DHA.

Second experiment
In order to prove the link between estrogen concentration in the brain and omega 3 fatty acid intake/DHA-synthesis, a second experiment was carried out.

This time, one group of mice were again fed on cottonseed oil and another group on cottonseed oil with DHA supplementation. In addition, a third group was fed on cottonseed oil with DHA supplements, and also letrozole, a drug which prevents estrogen synthesis.

When seizures were induced this time around, the mice in the group exposed to letrozole were found to have seizures much earlier than those fed on cottonseed fortified with DHA, thus confirming estrogen’s importance in preventing seizures.

Influential research
This research from Hiroshima University is the first time that brain estrogen, the synthesis of which is activated by dietary sourced DHA, has been shown to determine seizure latency.

According to the university’s press release, it is expected that these findings will contribute to the development of medication for treating epilepsy, as well as furthering our understanding of the relationship between lipid intake and brain health.

Due to a lack of high DHA-yielding fish oils in many Western diets it should also be of interest to dieticians, and influence the development of future brain boosting supplements.