I would not say that Reagan, who famously developed Alzheimer’s while in office, was notable for his health. But he was already fairly old when he took office.
This isn't what his doctors have said.
>...In 1989, just a few months after he completed his second term as president, Reagan underwent surgery to drain a subdural hematoma caused by a fall from a horse in Mexico. Such brain injury can increase the likelihood of developing Alzheimer’s disease or perhaps even cause it.
https://hekint.org/2023/11/30/the-medical-history-of-ronald-...
After this Reagan had annual exams for signs of Alzheimers and was diagnosed in 1994.