Omega-3 fatty acids offer protection against depression, physical blows and falls, and lots more. Japanese researchers at the University of Hiroshima believe they have worked out how omega-3 fatty acids work: they probably stimulate the production of estradiol in the brain.
The omega-3 fatty acid DHA stimulates the orphan receptor RXR, which in turn boosts the production of estradiol. And because estradiol vitalizes brain cells the Japanese believe that via estradiol DHA has positive neurological effects.
To test this theory the researchers gave one group of mice a diet containing soya oil for four weeks [this contained an average amount of omega-3 fatty acids]; another group of mice got a diet containing cottonseed oil [low in omega-3 fatty acids] and yet another group of mice a diet containing cottonseed oil plus DHA [high in omega-3 fatty acids].
At the end of the four weeks the mice were given an injection of PTZ, a substance that causes epileptic fits and damages brain cells.
In the mice that had been given DHA supplementation it took longer before they had an epileptic episode after being injected with PTZ.
The DHA made the P450arom gene work harder in the mice’s brain. This is the gene that causes cells to make aromatase, an enzyme that converts steroid hormones such as testosterone and androstenedione into estradiol.
The estradiol concentration rose as a result of the DHA supplementation.
The estradiol produced as a result of DHA also led to a stimulation of the ‘good’ estradiol receptor-beta [ER-beta] only. How this happened is not clear Stimulation of this receptor has effects elsewhere in the body, such as stronger bones, stronger muscles and suppler blood vessels. The other estradiol receptor, ER-alpha, stimulates the growth of fat tissue and some kinds of cancer cells.
DHA also caused a slight increase in stimulation of the androgen receptor.
“We have shown that 17-beta-estradiol protects hippocampal neurons from ischemia and environmental chemicals,” the researchers wrote in reference to previously published studies. “17-Beta-estradiol might be protective by suppressing oxidative stress. Both genomic and non-genomic pathways are thought to mediate the anti-oxidative action of 17-beta-estradiol.”
“For example, 17-beta-estradiol has been reported to attenuate oxidative stress via upregulation of anti-oxidative enzymes superoxide dismutase, glutathione peroxidase and catalase. Furthermore, 17-beta-estradiol can suppress nuclear factor-kappaB activity contributing to the transcription of a number of pro-inflammatory molecules.”
“In the case of non-genomic anti-oxidation pathways, 17-beta-estradiol is related to activating kinase signaling, regulating the rate of mitochondrial uncoupling, directly eliminating reactive oxygen species, and attenuating the inflammatory reaction of the microglia.”
“In conclusion, we found that dietary supplementation with DHA upregulates P450-aromatase expression, subsequently increasing the level of 17-beta-estradiol in the cerebral cortex,” the researchers concluded. “DHA-induced 17-beta-estradiol synthesis can suppress convulsive seizures via its anti-oxidative effects. The present study suggests that 17-beta-estradiol in the brain mediates the physiological actions of DHA.”
Sci Rep. 2017 Jul 24;7(1):6268.