The news comes four years after Pat Bowlen announced that he was diagnosed with the same progressive brain disease.
"I recently learned that I've joined my husband Pat and the millions of others who have been diagnosed with Alzheimer's disease," Annabel Bowlen said in a statement. "Since Pat's diagnosis, I have gained a vivid understanding of this disease's progression and its effect on those living with it as well as their families. My family and I have been -- and will remain -- dedicated supporters of Alzheimer's awareness, treatment and research funding.
"I decided to make my diagnosis public right away in the hope that it continues to raise awareness for those battling Alzheimer's and their loved ones. With June also being Alzheimer's & Brain Awareness Month, the timing was right for me to share this personal update with everyone."
Pat Bowlen, 74, left his role as controlling owner of the Broncos in July 2014. He placed the team's ownership in the hands of three trustees -- president/CEO Joe Ellis, team counsel Rich Slivka and attorney Mary Kelly.
"Our hearts go out to Annabel and the entire Bowlen family," Ellis said in a statement. "She's been a wonderful ambassador and advocate for the Broncos over the years, especially in recent seasons as Pat has focused on his own battle with Alzheimer's disease.
"All of us at the Broncos are behind Annabel and know she'll face this challenge with courage and determination. ... We commend Annabel for her brave public announcement and look forward to increasing our involvement in the Alzheimer's community."