London - It sounds like the ingredient list for an indulgent dessert. But red wine, chocolate and strawberries are more than a guilty pleasure. They could all help guard against diabetes.
A study found for the first time the high content of flavonoids found in berry fruits may regulate blood glucose levels, and stave off type 2 diabetes.
Flavonoids are antioxidant compounds found in plants, as well as tea, red wine and chocolate, which can protect against a wide range of diseases, including heart disease, hypertension, some cancers and dementia.
The study found the main protective effect came from higher intakes of anthocyanins, which are present in strawberries, blackcurrants, blackberries and blueberries.
Researchers from the University of East Anglia (UEA) and King's College London reveal that high intakes are linked with lower insulin resistance and better blood glucose regulation.
They also lowered inflammation which, when chronic, can lead to disease, says the study published today in the Journal of Nutrition.
Prof Aedin Cassidy from UEA's Norwich Medical School, who led the research, said 'We focused on flavones, which are found in herbs and vegetables such as parsley, thyme, and celery, and anthocyanins, found in berries, red grapes, wine and other red or blue-coloured fruits and vegetables.
'This is one of the first large-scale human studies to look at how these powerful bioactive compounds might reduce the risk of diabetes.
'Laboratory studies have shown these types of foods might modulate blood glucose regulation - affecting the risk of type 2 diabetes.
'But until now little has been know about how habitual intakes might affect insulin resistance, blood glucose regulation and inflammation in humans.'
Researchers studied almost 2,000 healthy women volunteers from TwinsUK who had completed a food questionnaire designed to estimate total dietary flavonoid intake as well as intakes from six flavonoid subclasses.
Blood samples were analysed for glucose regulation and inflammation, while insulin resistance, a hallmark of type 2 diabetes, was also assessed.
Prof Cassidy said 'We found that those who consumed plenty of anthocyanins and flavones had lower insulin resistance.
'High insulin resistance is associated with type 2 diabetes, so what we are seeing is that people who eat foods rich in these two compounds - such as berries, herbs, red grapes, wine- are less likely to develop the disease.
'We also found that those who ate the most anthocyanins were least likely to suffer chronic inflammation - which is associated with many of today's most pressing health concerns including diabetes, obesity, cardiovascular disease, and cancer.
'And those who consumed the most flavone compounds had improved levels of a protein (adiponectin) which helps regulate a number of metabolic processes including glucose levels.
'What we don't yet know is exactly how much of these compounds are necessary to potentially reduce the risk of type 2 diabetes' she added.
Prof Tim Spector, research collaborator and director of the TwinsUK study from King's College London, said 'This is an exciting finding that shows that some components of foods that we consider unhealthy like chocolate or wine may contain some beneficial substances.
'If we can start to identify and separate these substances we can potentially improve healthy eating.
'There are many reasons including genetics why people prefer certain foods so we should be cautious until we test them properly in randomised trials and in people developing early diabetes.'
Dr Alasdair Rankin, director of research for Diabetes UK charity, said the findings should be treated with caution.
He said 'There have been contradictory findings from other studies and, also, even if high flavonoid consumption and lower type 2 diabetes risk do tend to happen together, it does not necessarily mean that one is causing the other.
'So while interesting, this study is not the smoking gun that would finally persuade us that flavonoids really do help prevent type 2 diabetes.
'From the point of view of what people should do to reduce their risk of type 2 diabetes, we already recommend a healthy lifestyle that involves doing regular physical activity as well as eating a healthy diet to help maintain a healthy weight.
'This includes eating plenty of fruit and vegetables, some of which, such as berries, apples and pears, are rich in flavonoids.
'But for red wine and chocolate, which also contain them, our advice is to limit your consumption of these and this advice would be very unlikely to change even if further research did demonstrate that flavonoids reduce type 2 diabetes risk.
'This is because any health benefit from the flavonoids would be dramatically outweighed by the calories in the chocolate and the alcohol in the wine.' - Daily Mail