A walnut-enriched diet may help reduce the risk, delay the onset or slow the progression of Alzheimer's disease, a new study, led by an Indian-origin researcher, has found.
The study found significant improvement in learning skills, memory, reducing anxiety, and motor development in mice fed a walnut-enriched diet.
Researchers suggest that the high antioxidant content of walnuts (3.7 mmol/ounce) may have been a contributing factor in protecting the mouse brain from the degeneration typically seen in Alzheimer's disease.
Oxidative stress and inflammation are prominent features in this disease, researchers said.
"These findings are very promising and help lay the groundwork for future human studies on walnuts and Alzheimer's disease - a disease for which there is no known cure," said lead researcher Abha Chauhan, head of the Developmental Neuroscience Laboratory at the New York State Institute for Basic Research in Developmental Disabilities (IBR).
"Our study adds to the growing body of research that demonstrates the protective effects of walnuts on cognitive functioning," Chauhan said.
The research group examined the effects of dietary supplementation on mice with 6 per cent or 9 per cent walnuts, which are equivalent to 1 ounce and 1.5 ounces per day, respectively, of walnuts in humans.
This research stemmed from a previous cell culture study led by Chauhan that highlighted the protective effects of walnut extract against the oxidative damage caused by amyloid beta protein.
This protein is the major component of amyloid plaques that form in the brains of those with Alzheimer's disease.
Walnuts have other nutritional benefits as they contain numerous vitamins and minerals and are the only nut that contains a significant source of alpha-linolenic acid (ALA) (2.5 grammes per ounce), an omega-3 fatty acid with heart and brain-health benefits.
The researchers also suggest that ALA may have played a role in improving the behavioural symptoms seen in the study.
The study was published in the Journal of Alzheimer's Disease.
