Volunteers will be required to eat chocolate every day for a year
A university study of potential health benefits of dark chocolate is looking for new volunteers.
Forty post-menopausal women with type 2 diabetes are needed to test whether flavonoid compounds in chocolate can reduce the risk of heart disease.
The study's first volunteers ate chocolate every day for a year and will soon be tested for any health benefits.
The University of East Anglia (UEA) in Norwich said its research had now entered a "really exciting stage".
Dr Peter Curtis, of the UEA's School of Medicine, said: "Our first volunteers are about to return for their final visit to see if the markers of heart health - such as blood pressure and cholesterol levels - have changed.
"A successful outcome could be the first step in developing new ways to improve the lives of people at increased risk of heart disease."
The new volunteers must be under 76 years old and must not have had a period for at least one year or be taking HRT.
Volunteers must also be non-smokers and have been taking cholesterol lowering drugs such as statins for at least a year.
Participants will be required to eat a small amount of chocolate every day for one year and have their risk of heart disease tested on five occasions to see whether changes occur.
The UEA said that this will involve giving blood and urine samples, having an ultrasound scan of their arteries and filling in questionnaires about their lifestyle.
A spokesman said: "The study is based in Norwich and travel expenses are available up to a maximum of a 60-mile round trip.
"People who want to take part but live further away can still do so, but they would only get expenses for 60 miles, which works out as £21 per visit."