Dick Van Dyke Says His Wife Arlene Makes Him Feel Much Younger

Dick Van Dyke's less than a month away from becoming a centenarian ... and he says one of the secrets to his longevity is his wife, Arlene Silver!

The actor spoke about his spouse's role in his long, long life in an excerpt from his new book "100 Rules for Living to 100" -- released on Tuesday -- and he credited Arlene with making him feel "somewhere between two-thirds and three-quarters my age," reports Fox News.

FYI ... Van Dyke and Silver met in 2006 when she was working as a makeup artist at the SAG Awards.

The actor was previously married to his first wife, Margie Willett, from 1948 to 1984, and he was in a long-term relationship with Michelle Triola, which lasted until her death in 2009.

Van Dyke eventually began dating Silver, who worked as his makeup artist, and they ended up tying the knot in 2012.

Although there's a 48-year age gap between the two -- Silver's only 54 years old -- Van Dyke never really took the difference into consideration, and he apparently told her she'd keep him "feeling young forever" during a discussion recorded for his book.

Plus, the actor said his wife was the one who kept him from becoming curmudgeonly in his old age ... and if it hasn't happened by now, it'll probably never happen!