For as long as it can be remembered, there has been a search to find the answer to why some people live longer. Many reasons have been advanced and theories offered, but no one single reason has found general acceptance with the exception of one — a person’s genetic makeup. Such reasons as diet and where a person lives have given evidence of reaching an advanced age.

The world’s oldest person reportedly is Emma Morano, who celebrated her 117th birthday Tuesday in Verbania, Italy. Her doctor credits genetic makeup as the reason for her 117 years “and nothing else.” He’s probably right.

But that won’t stop others in looking for the magic reason for a long life. The search will go on.

Morano’s gifts included her favorite cookies, which she ate with some milk. Her doctor remarked that when Morano was young, “everyone used to say you were weak and sick.”

Morano is believed to be the last surviving person in the world who was born in the 1800s. By the way, Italy is known for its centenarians, many of whom live on the Mediterranean island of Sardinia.