Previous studies have shown that risk factors for heart disease in healthy people can be reduced by dietary flavonoids, which occur in tea, red wine, fruits and vegetables.
The University of East Anglia team instead examined the effect of flavonoids in a high-risk patient group.
In a 12-month trial, they assessed 93 postmenopausal women with type 2 diabetes, aged between 51 and 74 years and receiving statin therapy.
Half of the patients were given two small bars of chocolate each day. The bars contained a high dose of two flavonoid sub-classes: flavan-3-ols, which are found in cocoa and tea, and isoflavones, which are found in soy. The other patients were given standard chocolate bars, acting as a placebo.
Patients who received the extra flavonoids had reduced LDL cholesterol and insulin levels, cutting peripheral insulin resistance and increasing insulin sensitivity.
Dr Ketan Dhatariya, one of the researchers, said the study had found ‘an important result’.
‘We are not saying that people with diabetes should be eating lots of chocolate, but that foods that are rich in flavonoids can potentially reduce the risk of heart attacks and strokes, which sadly remain the leading causes of premature death in this group of women.’
Further research is now needed to determine the relative influence of the two flavonoid sub-classes featured in this study, and to examine whether similar effects are achieved in other patient groups.