Scientists are seeking volunteers from Norfolk to find out whether blueberries can cut the risk of people developing heart disease and diabetes.

The University of East Anglia researchers want to see whether drinking blueberry milkshakes can reduce the negative health effects which come from eating food rich in calories.

They will investigate health markers linked to heart disease and diabetes to see how differences in the way that people process blueberries after eating them, affect their health.

Prof Aedin Cassidy, who leads the Department of Nutrition at UEA's Norwich Medical School, said: "Large scale studies have shown that eating blueberries and anthocyanins - a naturally occurring flavonoid and the compound responsible for the blue colour of blueberries - can reduce the risk of developing heart disease and diabetes.

"But not everyone receives the same health benefits after eating the same foods and the reason for this is not well understood.

"In the case of blueberries and anthocyanins, we think that differences in the way that people process and metabolise these foods may hold the key to understanding why they experience different health effects."

Study coordinator Dr Peter Curtis, also from Norwich Medical School, said: "This research will determine whether a single portion of blueberries continues to affect health for up to two days after eating them.

"Our previous studies have shown that the by-products of food metabolism remain in the body for this extended period."

The research team is looking for 350 volunteers, who are overweight but generally healthy, aged 50 to 80, non-smokers and who are not currently taking blood pressure medication or hormone replacement therapies.

Those with a history of heart disease, cancer or diabetes cannot take part.

Eligible volunteers will be asked to consume a blueberry milkshake and have urine samples collected for analysis over three days.

People who process blueberries either quickly or slowly will be invited to participate in the second part of the study - which will look at how eating either an energy dense meal containing blueberries or a placebo affects health.

Assessments, including the collection of blood and urine samples, will be made over one full day, and for two hours on the morning of the two following days.

The trial will take place in the new NHS research facility at the Quadram Institute at Norwich Research Park at Colney and participants will be reimbursed for travel costs and parking.

For more information on the study and eligibility, call 01603 593266 or email amp.study@uea.ac.uk.