To the rites of middle-age passage, some families are adding another: buying marijuana for aging parents.

Bryan, 46, a writer who lives in Illinois, began supplying his parents about five years ago, after he told them about his own marijuana use. When he was growing up, he said, his parents were very strict about illegal drugs.

“We would have grounded him,” said his mother, who is 72.

But with age and the growing acceptance of medical marijuana, his parents were curious. His father had a heart ailment, his mother had dizzy spells and nausea, and both were worried about Alzheimer’s disease and cancer. They looked at some research and decided marijuana was worth a try.

Bryan, who like others interviewed for this article declined to use his full name for legal reasons, began making them brownies and ginger snaps laced with the drug. Illinois does not allow medical use of marijuana, though 14 states and the District of Columbia do. At their age, his mother said, they were not concerned about it leading to harder drugs, which had been one of their worries with Bryan.