That longevity in human beings is often determined by wealth as much as genetic factors should not be a surprise. There are several reasons why not having any money worries can result in a person living a long life.
The Elimination of Stress
Financial worries can affect a person's health in a number of ways. Most obviously is stress, which, in turn, can result in high blood pressure and heart problems. Having not much money can result in having to make do with a poor diet, which will ultimately affect a person's health to a greater or lesser degree. Alcoholism and drug problems can also be a problem for people struggling to cope with the harsh realities of life.
With no money concerns, a person in old age doesn't have to worry about heating bills. Many old people do die each year because they are too scared of having sufficient heating - they worry about how much it will cost.
Money also allows a person to spend more on their well being than a poorer person, who is struggling just to have enough to buy food and pay bills. Even in the UK, where the state is supposed to look after the population, people with money will choose to have private treatment, because they see it as the better option for their health.
Money can also aid health in less obvious ways. Just being able to buy comfortable furniture or a new bed when it's necessary can ward off back pain. Not everyone will be able to make the same choices.
There will be exceptions to the rule, but, generally people who don't have financial worries will benefit in so many ways. The exceptions can be that someone who is rich is self-indulgent and doesn't look after themselves. Conversely, some people who are struggling to make ends meet will try and live healthily and, if they have the right genes, can live to be 100.
A consequence of old age is the increasing vulnerability of mind and body. This vulnerability will be exacerbated if a person is constantly worrying about money issues and having to make decisions that will affect their health. Despite the fact that this is the 21st Century, the human race has still not found a way which allows all people to go into old age on more or less an equal footing. For some, a lack of money will mean failing to reach their life expectancy.