A new study has found that fish oil supplements known as omega-3 will not reduce mental decline. The study findings are different from many observational studies carried out in the past that states that the supplements are beneficial.

Study’s lead researcher Emily Chew has said that in their study, they have not found any benefit of omega-3 supplements for preventing cognitive decline. The researchers found no difference in the cognitive score of people taking fish oil compared with the placebo group after five years.

Dr Chew, deputy clinical director at the National Eye Institute, also said that cognitive decline may take place over the years. But their study did not continue that long. He said that short-term supplementation given after it is too late may not prove effective.

There is a possibility that having foods than any specific single supplement may have an effect. In the study, 3,000 patients having men and women whose average age was 70 were recruited. They were divided into groups.

One of the groups has to take regular dose of two omega-3 fatty acids (650 mg of EPA and 350mg of DHA) and the other group has to take a placebo. The researchers tested participants’ cognitive function after every two years.

After five years of research, the scientists did not find any difference in the cognitive scores of people who have taken omega-3 compared and those who have not.