Evidence for the benefits of fatty acids from fish is so strong that the chemical is to be used by pharmaceutical companies to develop anti-depressant drugs, reports Reuters.
Eating fatty fish is thought to help cure depression, but in order to allow for a regular dietary intake, drugs based on the acid will soon be available to treat the illness.
An antidepressant drug based on eicosapentaenoic (EPA) acid found in fish could be on the market in two years time, according to the researcher David Horrobin, from the private-owned British Laxdale Ltd.
He said that the majority of the human brain consists of fat, but about a fifth of that fat cannot be formed by the body and people have to get it from their diet.
Two studies published so far have shown that EPA in a pure form helped reduce depression in patients who had not earlier responded to antidepressants or who had initially responded but then seen a setback.
"It is surprising how strong the effect is. It is a very big effect compared with standard antidepressants," Horrobin said, and referred to two new studies, soon to be published, that show similar results.
Research has found that populations who consume high quantities of fatty fish are less prone to depression, bringing about the relationship between the food and the illness. For example, depression is rare in Far Eastern countries, such as Japan, where fish is a popular food, and the illness is more common in North European countries.
The US Food and Drug Administration (FDA) had given researchers a lot of guidance and the authority was likely to speed up the drug's entry into the markets, Horrobin said.
"If the dossier is complete, they (the FDA) could give it fast-track approval," he said.
The researcher also noted that the link between depression and heart problems was another emerging area of research. EPA and another fatty acid, docosahexaenoic (DHA), can be used to treat and prevent cardiovascular problems.
While a drug based on the pure form of fish acids would make it possible to treat patients with an optimal dose, a couple of weekly helpings of fatty fish, such as herring or sardines, may also help fight depression, Horrobin said.
EPA and DHA acids are found in meat and eggs but in small amounts. All green vegetables, especially flax seeds, have the ingredient, but fish is by far the best source.