Brain-fitness games soar, but do they work?

Based on the premise of "use it or lose it," more and more seniors and increasingly their baby boomer counterparts are trying to keep their brains in fighting trim with crossword puzzles, Sudoku and video games.

What's driving the trend are claims that exercising neurons and their connections may help stave off the development of Alzheimer's and other forms of dementia.

Dr. Donald Stuss, vice-president of research at Baycrest in Toronto, says not that long ago, scientists thought the brain "was fixed" after it had reached full development in childhood.

But in the last 15 years, studies have shown that the brain has far more plasticity than previously believed, and can even grow new neurons under certain conditions.

"Whatever you do will be helpful ... because we know the more active you are, whatever you do it will have some potential benefit," he says of giving the neurons regular workouts.

Yet there is no scientific proof for many of these brain-fitness games that they actually improve cognitive ability over the long-term, experts say. Carefully controlled clinical trials to prove their worth haven't been done.