If you are one of the few people who don't have a friend or family member who has been affected by this dreadful illness the chances are you soon will be.

It robs the sufferer of their dignity as well as their memory. It can lead to all sorts of emotional pain: like finding out four times in an hour that your mother has died when she has actually been dead for 50 years.

And it affects everyone around the person with the illness as slowly but surely they stop recognising children, spouses, friends.

I would therefore be hugely grateful if you could help me to do a little bit to help those currently affected and prevent future generations from having to deal with it at all.

Any support you can give would be most welcome. I will no doubt suffer short term pain during the course of my bike ride, but it will go after a couple of days. Alzheimer's never goes away. It just gets steadily worse and worse.

Alan