WASHINGTON - Adding some walnuts to an otherwise healthy diet may help older people improve memory and behavioural skills, according to an animal model study.

Walnuts contain polyphenols and other anti-oxidants and essential fatty acids. Polyphenols are the most abundant group of plant phenolic compounds, known to provide much of the flavour, colour and taste to fruits, vegetables and seeds.

The study was conducted by researchers with the Human Nutrition Research Centre on Ageing (HNRCA) at Tufts University in Boston.

The ageing brain undergoes many changes resulting in altered or impaired neuronal functioning. In aged rodents, these impairments are seen as poor performance on age-sensitive tests of balance, coordination, and ’spatial’ working memory.

For the study, weight-matched, aged rats were randomly assigned to one of four diet groups. For eight weeks, the rats were fed special chow mixes that contained either two, six or nine percent walnuts - or no walnuts - before undergoing motor and memory tests.

For comparison, the six percent walnut study diet is equivalent to a human eating about seven to to nine walnuts daily. That counts as both a two-ounce equivalent from the ‘meat and beans group’ and two teaspoons toward a daily allowance of dietary oil, said a HNRCA release.

The study found that in aged rats, the diets containing two or six percent walnuts were able to improve age-related motor and cognitive shortfalls, while the nine percent walnut diet also improved memory.

These findings were published in the British Journal of Nutrition.