The brains of elderly women who practice yoga are thicker in the area associated with attention and memory, say Brazilian scientists, meaning that yoga could be a way to protect against cognitive decline that's associated with aging.

As we age, the brain changes. One change involves the cerebral cortex, which becomes thinner and is linked to cognitive decline.

How does yoga help the brain? "In the same way as muscles, the brain develops through training," explains Elisa Kozasa of Hospital Israelita Albert Einstein in São Paulo, Brazil.

"Like any contemplative practice, yoga has a cognitive component in which attention and concentration are important," she said.

Previous studies have suggested that yoga can have greater health benefits than similar aerobic exercises, and yoga practitioners have shown improved awareness, attention and memory. Older adults with mild cognitive impairment have also shown improvements after undertaking a short yoga training program.

However, the research team wanted to see if elderly long-term yoga practitioners had any differences in brain structure when compared to healthy elderly people who had never practiced yoga.

They recruited 21 female yoga practitioners (also known as yoginis) who had practiced yoga at least twice a week for a minimum of 8 years, although the group had an average of nearly 15 years of yoga practice. They were compared to another group of 21 healthy women, who had never practiced yoga, meditation or any other contemplative practices, but who were well-matched to the yoginis in terms of their age — all were at least 60.  

"We found greater thickness in the left prefrontal cortex in the yoginis, in brain regions associated with cognitive functions such as attention and memory," says Rui Afonso, another researcher involved in the study.

The study was published in Frontiers in Aging Neuroscience.

Other recent studies have found that yoga benefits a number of health issues. A study published in The Journal of Alternative and Complementary Medicine found that yoga combined with coherent breathing instruction significantly reduced symptoms in people with depression.

Researchers from Boston's Massachusetts General Hospital found that people who practice deep relaxation techniques, including yoga and meditation, make 42 percent fewer trips to their doctors, and lab use dropped by 44 percent when compared to the year before training.

Yoga may also be a safe and effective way for people with arthritis to keep moving, according to a study from Johns Hopkins. A group of 75 volunteers with two common forms of arthritis, knee osteoarthritis and rheumatoid arthritis, were either put on a wait list or participated in twice-weekly yoga classes plus a weekly at-home session.

After eight weeks, those who were in the yoga group reported a 20 percent improvement in pain, mood, and the ability to perform daily activities when compared to the control group.