"Scientists do not know why the brain starts to slow down past a certain age."
SOME scientists don't. Many do. It's called lifestyle.
Lay off the drugs, eat cleanly, stay active, and live right, and your body can easily serve you just as well as you age. Unfortunately, most Americans are counterexamples to this. Aging doesn't cause us to slow down and lose our health, poor living does, at any age. I have friends and relatives in their teens and twenties who can't do a single pull-up, a single push-up, or carry their own luggage throught the airport. Many in their twenties are balding or have gray hair and can barely make it up a flight of stairs. OTOH, I play bridge with some seniors in their nineties who are as sharp as tacks. Still.
Discrimination based on age is stupid and illegal.
And at a time when anyone can publish anything anywhere, it's a good idea to take all health advice on the internet with a grain of salt. For every study you cite, I can probably google another one with the opposite point of view.
Still wanna race me to those donuts?
Or we can webboggle.shackworks.com. I like the 5x5 board. I'll spot you 5 years, er I mean, points.
Hell... I have some of the symptoms in that article, and I'm only 23. I don't think the ability to recall random strangers' names or remember why I walked into a room really affects my coding, though. I would argue that the older I get, the better I get at remembering the things that really matter (big picture stuff, the project I'm working on, etc.) and forgetting the rest.
Also, here's a counterexample, a checkers player who was basically undefeated well into his 60s:
I wonder what the age of the scientist is who published finding. I'm sure he's 20 and makes very very fast decisions ;-)
Edit: Prof Wesnes graduated in 1973, so presumably he's around 60. He's a researcher and CEO of a high-tech company. Should such an old person really be doing research? Should Paul Graham not be thinking about passing his duties on to Paris Hilton?