The singer's announcement can have a positive effect on research, according to Oberdorf.
"If a celebrity has the personal ability to use the media spotlight for greater good, that's great," she said.
The disease was named in 1817 by Dr. James Parkinson, who published, "An Essay on the Shaking Palsy," based on six cases he had observed in his London medical practice.
Researchers now say that most cases of Parkinson's disease are not genetic but "sporadic."
The latest thinking is that the disease is rooted in the function and degradation of mitochondria, the cells' power producers.
"Brain-wide death of dopamine is only one part of a very extensive disease," said Virginia Commonwealth University's Bennett.
Therapy is only symptomatic with drugs like levadopa to replace lost dopamine nerve cells and deep brain stimulation to silence overactive ones.
"Treatment for the underlying disease does not exist," he said.
But people who start young and eat a so-called Mediterranean diet, rich in fruits and vegetables, can "stave" off the disease, according to Bennett.
One Japanese study, comparing the healthy Asian diet, full of fish and mushrooms, to the typical meat and fat-heavy Western diet, showed a decreased risk of 40 percent.
"It's what you put in your grocery cart -- diet is a big deal," he said.
There has also been some research to suggest an association between Parkinson's and exposure to pesticides.
Exercise is also a key to reducing risk.
"I am the darling of all personal trainers," Bennett said. "I beat on to [patients] about lifestyle changes because the ones who do have so much better quality of life and it can have a major impact on progression of the disease."
As for Ronstadt and Fox, their openness about having Parkinson's disease can only help the cause of awareness and research, according to both Bennett and Oberdorf.
"I personally know many people with Parkinson's who have great humor about their trials and tribulations in life," said Oberdorf.
"Having said that, it certainly complicates your life and you need to take care of yourself and learn to live well with it," she said. "It is, particularly in the later stages, supremely difficult and difficult on family."