FOR Epsom couple Jane and Colin Cleary healthy is a natural part of life.

They decided to join the ASPREE study because they had good experiences with medical practitioners in the past.

They have been on the mystery pill for three years.

At the beginning they took blood and urine samples from the couple and they now have a check-up every three months.

Mrs Cleary said at the end of each 12 month period they have a more thorough check-up along with a mental health assessment.

Mrs Cleary said she had much to be grateful for.

"It seems very right and proper to give something back," she said.

"If we can be of some help to the system."

Although the pair were teachers before they retired they are now keen to give back to the system.

The pair are involved in maintaining their health throughout the year.

Mrs Cleary said she walks, participates in qi gong for upper body exercise and rides everywhere she physically can.

"I ride my bike into town and back home again," she said.

"We are very lucky in Bendigo because we have so many tracks and it makes it possible for us to cycle."

She said she and her husband had only ever been patients for doctors to operate on but this experience allowed them to be more a part of the process.

Mrs Cleary said she believed the more the study found out the better it would be for future generations.

She said the possible benefits out-weighed any possible negatives.

Macedon resident John Cross is also on the trial.

He is one of the thousands of volunteers from across the country involved in this study.

He attended the information session on the study at the start of the week.

He volunteered to do the study because he was curious.

He said he had been going to the same doctor for the last 30 years and they got him interested in the study.

As an engineer he had always had an interest in the way things were made and the human body was no exception.