Red grapes and oranges could hold the key to combatting obesity, researchers have said.
Scientists studied the effects of combining two compounds - trans-resveratrol (tRES), found in red grapes, and hesperetin (HESP), found in oranges.
When the compounds were merged into a pill and given to overweight people, it decreased blood glucose, improved the action of insulin and improved the health of arteries - in as little as eight weeks.
Professor Thornalley, who led the research, said: "This is an incredibly exciting development and could have a massive impact on our ability to treat these diseases.
"As well as helping to treat diabetes and heart disease it could defuse the obesity time bomb."
Researchers said the compounds tRES and HESP work together to increase a protein in the body called glyoxalase 1 (Glo1).
This neutralises a compound called methylglyoxal (MG), which is a major contributor to the damaging effects of sugar.
Having increased levels of MG with a high energy diet intake is a driver of insulin resistance, which can lead to type 2 diabetes. It also damages blood vessels and impairs handling of cholesterol associated with increased heart disease risk.
A team of researchers from Warwick University merged the compounds tRES and HESP into a capsule. They also created a placebo pill.
The pills were then given to 32 overweight and obese people aged 18-80, for a period of eight weeks.
The participants were asked to maintain their usual diet while they took the pills.
Their food intake was monitored through a dietary questionnaire and they were also asked not to alter their daily physical activity.
The team found that the highly overweight subjects who had BMIs of over 27.5, and took the capsules containing the two compounds, displayed increased Glo1 activity, decreased glucose levels, improved working of insulin, improved artery function and decreased blood vessel inflammation.
They said the effects of taking the pill for eight weeks was similar to that achieved with gastric bypass surgery after six months.
Currently Metformin is considered for the treatment of overweight and obese people who have an increased risk of developing type 2 diabetes.
However in the study, the combination of the fruit compounds was found to be more effective than Metformin at reducing blood sugar in the obese and overweight trial participants.
Professor Thornalley said: "Obesity, type 2 diabetes and cardiovascular disease are at epidemic levels in Westernised countries.
"Glo1 deficiency has been identified as a driver of health problems in obesity, diabetes and cardiovascular disease.
"Diabetic kidney disease will be the initial target to prove effective treatment for which we are currently seeking commercial investors and partners.
"Our new pharmaceutical is safe and expected to be an effective add-on treatment taken with current therapy."
He continued: "The key steps to discovery were to focus on increasing Glo1 and then to combine tRES and HESP together in the formulation for effective treatment.
"As exciting as our breakthrough is it is important to stress that physical activity, diet, other lifestyle factors and current treatments should be adhered to."
Researchers now hope manufacturers will want to explore the use of the compound as pharmaceutical products.
Their research was published in the journal Diabetes.