London: Dark chocolate enriched with extra virgin olive oil may improve your heart health by increasing good cholesterol levels and preserving the 'repairing cells' critical for maintaining blood vessels, a study has found.
"A healthy diet is known to reduce the risk of cardiovascular disease," said Rossella Di Stefano, a cardiologist at the University of Pisa in Italy.
"Fruits and vegetables exert their protective effects through plant polyphenols, which are found in cocoa, olive oil, and apples," Di Stefano added.
"Research has found that the Italian Panaia red apple has very high levels of polyphenols and antioxidants," he said.
The study tested whether consumption of dark chocolate enriched with extra virgin olive oil or Panaia red apple was linked to atherosclerosis - fat build-up in the artery walls - in healthy people who had cardiovascular risk factors.
The study included 26 volunteers (14 men, 12 women) with at least three cardiovascular risk factors (dyslipidaemia, smoking, hypertension or family history of heart disease) who received 40 grammes of dark chocolate daily for 28 days.
For 14 consecutive days it contained 10 per cent extra virgin olive oil and for 14 consecutive days it contained 2.5 per cent Panaia red apple.
The two types of chocolate were given in random order. Progression of atherosclerosis was assessed by metabolic changes, lipid profile, blood pressure and circulating endothelial progenitor cells (EPC), which are critical for vascular repair and maintenance of the cells inside blood vessels.
Urine and blood samples were collected at baseline and after the intervention. Urine samples were analysed by proton nuclear magnetic resonance spectroscopy for endogenous metabolites.
Circulating EPC levels were assessed with flow cytometry. Smoking status, body mass index, blood pressure, glycaemia and lipid profile were also monitored.
After 28 days, the researchers found that the chocolate enriched with olive oil was associated with significantly increased EPC levels compared to both baseline and after consumption of apple-enriched chocolate.
Olive oil-enriched chocolate was associated with significantly increased high-density lipoprotein or "good" cholesterol and decreased blood pressure compared to baseline.
"We found that small daily portions of dark chocolate with added natural polyphenols from extra virgin olive oil was associated with an improved cardiovascular risk profile," said Di Stefano.
"Our study suggests that extra virgin olive oil might be a good food additive to help preserve our 'repairing cells', the EPC," researchers said.