I saw an interesting article in The Age a couple of months ago... and if I could remember what date it was published, I'd be able to add the link to this page. Instead, I had to Google and found a similar article in the New York Times at http://newoldage.blogs.nytimes.com/2009/06/11/can-dementia-be-prevented/.
The articles discuss a study being conducted to find out whether or not age-related memory problems can be reversed or prevented. A number of possible preventative measures are being tested; diet, exercise and learning new craft skills.
No, the last entry is not a joke or a lame attempt at self-promotion. There is some evidence that learning new craft skills helps to prevent dementia-type disorders in older adults.
The original version of the "use it or lose it" theory focussed on getting older adults to solve puzzles - and created a bonanza for brain training games, Sudoku, crossword books and so forth. These are fine as far as they go: but they focus on a very narrow skillset, which may not necessarily help with day to day living. Learning a new craft is a more complex task which (theoretically!) staves off the negative effects of aging by creating new synapses in your brain.
The catch? To get any benefit, you need to learn a new skill: it's not enough to continue to use a skill that you already have. So instead of loading up your bookshelves with more knitting patterns, consider learning how to crochet - or tat - or tricot - or spin. Learn a foreign language (and download knitting patterns in that language for practise). And keep the puzzles going too - every challenge helps!
* Need help learning new skills? Go to our Beginner Classes and Advanced Classes pages for more information.
**Disclaimer: Remember that I run a wool shop. I am not a qualified researcher and don't know a darned thing about dementia, its causes or possible cures. This is my over-simplified version of a general interest article in a newspaper. Please don't sue me if it turns out that I got it wrong...**