Cariou was born as Constance Juliette Jouin in Nantes, Loire-Atlantique, France on 8 May 1895. As a child, she remembered wanting a pink dress, a request that her mother refused. She married and had a daughter, Paule.
In her 80s, Cariou moved to Châteauneuf-Grasse in the Provence region to live with her daughter and her family. As a supercentenarian, she was described as being a hard worker who adorned a pretty smile.
Cariou died on 29 August 2007 at the age of 112 years, 113 days. She was survived by her daughter Paule, her son-in-law Cleto, and her granddaughter Patricia.
At the time of her death, Cariou was the second-oldest resident of Provence-Alpes-Côte d’Azur after 113-year-old Simone Capony, who died less than three weeks after her. She was also the third-oldest person to die in the region, after Capony and Jeanne Calment, the oldest person ever.
Cariou’s age was verified by Laurent Toussaint (GRG) and Cyril Depoudent (ESO), and was validated by each organisation on 21 October 2005 and 9 April 2021 respectively.