Absolutely none of this is true.
- Alzheimer's is only one specific disease that leads to rapid mental breakdown. There are many forms of senility, all of which including Alzheimer's become more likely as you get older, which means that
- There is absolutely a strong correlation between age and degraded mental facilities. If I gave you three citations I'd be leaving out hundreds more citations.
- There won't be a scientific breakthrough that doubles the average lifespan of every human on earth. There are so many flaws with this idea it's exhausting just to think about it.
- Mandatory retirement ages are in use all over the place. Judicial appointments have this in place already in 18 states. Executive boards can legally have this rule in place as well. Any situation where old age in a job is a safety issue creates an exception in the form of an unmet bona fide occupational qualification. I would definitely argue that old men who create policy for hundreds of millions of people create a safety risk for those people if they aren't mentally qualified to do the job.
... or want it, considering he's not really affiliated with them any more.