walnut
In a study reported in Journal of Nutrition, Health and Aging, eating just 13 grams of walnuts per day helped improve memory, concentration and other important cognitive functions in the participants.Pauline Mak/Flickr

A diet rich in walnuts may benefit the brain, the latest research shows.

In a study reported in Journal of Nutrition, Health and Aging, eating just 13g walnuts per day helped improve memory, concentration and other important cognitive functions in the participants.

For the study, Dr Lenore Arab and colleagues from The University of California, Los Angeles in US analysed walnut consumption among people who participated in the National Health and Nutrition Examination (NHANES) surveys conducted between 1988 to 1994 and 1999 to 2002 in US. Participants varied from ages 20 to 90.

People who consumed high levels of walnuts scored better in all six cognitive tests than people who were not eating walnuts.

"It isn't every day that research results in such simple advice - eating a handful of walnuts daily as a snack, or as part of a meal, can help improve your cognitive health," Dr Arab, said in a news release.

These results come as a support to several experiments conducted on animals in the past. Mouse studies have shown that walnuts were highly effective in reducing cognitive impairment and preventing progression of Alzheimer's disease into dementia, a syndrome related to the brain that leads to memory loss, difficulties in communicating, thinking, planning and performing daily routines.

Researchers said that several important nutrients and minerals found in walnuts may have given the health benefits. Walnuts are high in anti-oxidants and omega 3-fatty acids alpha-linolenic acid (ALA). They are also rich sources of calcium, magnesium, iron, sodium, zinc, copper, potassium, phosphorus, manganese and selenium. Vitamins found in walnuts include vitamin C, vitamin B1, folate, vitamin B6, vitamin B2, vitamin A, vitamin E, vitamin E and vitamin K.

Walnuts have also been shown effective in fighting cancer, obesity, diabetes, infertility and cardiovascular diseases.