Yoga and meditation are more effective than memory exercises for combating the mental decline that often precedes Alzheimer's, research has shown.
People who practised yoga regularly were also less likely to be depressed and anxious, and were better able to cope with stress, the study found.
Regular practice could be a safe, low-cost solution to improving brain fitness and warding off ageing, researchers said.
To come to their conclusions, scientists recruited 25 volunteers over the age of 55 who had reported memory issues such as forgetting names and faces, missing appointments or misplacing belongings.
They split them into two groups, with one carrying out memory exercises and the other yoga and meditation.
They found that after three months, both were equally good at improving verbal memory skills, which help people recall names and word lists.
But the spiritual path provided added benefits in the form of enhanced visual-spatial memory.
This comes into play when recalling locations and navigating while walking or driving, and helps reduce anxiety.
Eleven participants received weekly, hour-long memory training sessions and performed exercises ranging from crossword puzzles to computer-based tasks.
The other 14 were given an hour-long yoga session once a week and practised Kirtan Kriya meditation at home for 20 minutes each day.
Lead researcher Harris Eyre, from the University of Adelaide, said: "Historically and anecdotally, yoga has been thought to be beneficial in ageing well, but this is the scientific demonstration of that benefit. "We're converting historical wisdom into the high level of evidence required for doctors to recommend therapy to their patients."
It's better boost than word puzzles, study findsYoga and meditation could be a simple, safe and low-cost solution to improving ... brain fitness.
The form of yoga used in the study, known as Kundalini, focuses on breathing, meditation and chanting as well as poses designed to increase strength and flexibility.
It incorporates Kirtan Kriya meditation, which involves chanting, hand movements and visualisation of light, and has been used for centuries in India to prevent mental decline in older adults.
After 12 weeks, the scientists saw similar verbal memory improvements in both groups.
However, visual-spatial memory was increased to a greater degree in the yoga-meditation group.
Participants practising yoga and meditation were also less likely to be depressed and anxious, and were better able to cope with stress.
Mood enhancement is important because of the emotional difficulties involved in coming to terms with cognitive impairment, said the researchers.
"When you have memory loss, you can get quite anxious about that and it can lead to depression," said co-author Professor Helen Lavretsky, from the University of California at Los Angeles.
The memory improvements coincided with altered brain activity, which was monitored using functional magnetic resonance imaging (fMRI) brain scans.
Changes in the way the brain cells connect with each other were seen in both groups, but they were only statistically significant in the people practising yoga.
Professor Lavretsky said: "If you ... are trying to improve your memory or offset the risk for developing memory loss or dementia, a regular practice of yoga and meditation could be a simple, safe and low-cost solution to improving your brain fitness."