What's a word for "almost guarantee?"

What's a word for "almost guarantee?" I've done some research and can't seem to find anything. Here is my sentence:

Building a healthy lifestyle is important to guarantee a long life.

You can't necessarily "guarantee" that you'll live a long life. You could be the healthiest person on earth, yet die in a car accident. So, with that being said, what single word could I use that is along the lines of "almost guarantee?" I could use this sentence instead (unless a singular form of "almost guarantee" is available):

Building a healthy lifestyle is important to guarantee a long life to the best of one’s abilities.

This sentence (shown above) would definitely need some restructuring, though. Any suggestions are welcome. =)

Solution 1:

In this context, one could write "promote" or "encourage."

Promote:

Further the progress of (something, especially a cause, venture, or aim); support or actively encourage. [Lexico]

Encourage:

Help or stimulate (an activity, state, or view) to develop. [Lexico]

Promote is the better choice (in my opinion), but both are applicable to your situation.