Professor Aedin Cassidy has led the research at the University of East Anglia in Norwich.
She told Sky News: "Small changes to the normal diet you have can have significant effects on prevention efforts.
"We show that one portion of berries every day can help you control your blood sugar levels but also prevent you having a heart attack."
The study involved 2,000 women keeping a diary of all the food and drink they consumed and blood samples being analysed.
It has emerged that eating high levels of flavonoids such as red wines, dark chocolates and berries can provide protection from Type 2 diabetes as it helps the body to regulate sugar levels.
This new discovery is also believed that chocolates could help to reduce the risk of heart disease and also chronic inflammation.
Dietician Dr Sarah Schenker also told Sky News: "This is another study that strengthens what we know about them in our diet. They have already been shown to be powerful against cancer and heart disease.
"But there is always a tipping point with things like chocolate, red wine and even coffee ... too much outweighs the benefits."