Washington, May 24 (IANS): Omega-3 fatty acids -- found in fish, nuts and certain seeds like flax seeds -- can improve cognitive abilities among the elderly, finds a study.

It found that older adults at risk of late-onset Alzheimer's disease who consumed more omega-3 fatty acids did better than their peers on tests of cognitive flexibility.

When it comes to fat, there is one type you do not want to cut back on: Omega-3 fatty acids.

Two crucial ones - EPA and DHA - are primarily found in certain fish.

ALA (alpha-linolenic acid), another omega-3 fatty acid, is found in plant sources such as nuts and seeds.

"Recent research suggests that there is a critical link between nutritional deficiencies and the incidence of both cognitive impairment and degenerative neurological disorders, such as Alzheimer's disease," said lead author Aron Barbey from University of Illinois.

The findings add to the evidence that optimal nutrition helps preserve cognitive function, slow the progression of ageing and reduce the incidence of debilitating diseases in healthy ageing populations.

The study focused on 40 healthy older adults between the ages of 65 and 75 who are carriers of a gene variant that is known to contribute to the risk of developing late-onset Alzheimer's disease.

The researchers tested participants' cognitive flexibility, measured levels of the fatty acids EPA and DHA in their blood.

"We were able to show that higher volume in the anterior cingulate cortex (a brain region known to contribute to cognitive flexibility) was an intermediary in the relationship between omega-3 fatty acids and cognitive flexibility," the authors said.

Cognitive flexibility refers to the ability to efficiently switch between tasks.

The study appeared in the journal Frontiers in Aging Neuroscience