People with dieting blues should try swapping white corn tortillas for blue. A recent study suggests that the coloured flatbreads are healthier, especially for diabetics and dieters, Sara Jensen reports in Chemistry & Industry, the magazine of the SCI.

Scientists in Mexico, home of the taco, found that tortillas made from blue corn had less starch and a lower glycmic index than their white counter parts. They also found that the blue tortillas had 20% more protein than white (Journal of the Science of Food and Agriculture, DOI 10.1002/jsfa.3008).

The glycmic index (GI) ranks carbohydrates according to their effects on blood glucose levels. Foods with a lower GI are considered healthier as they slowly release sugar into the bloodstream. This reduces fluctuations in our blood glucose and insulin levels, helping to maintain a steady supply of energy. Low GI foods are said to have long-term health benefits, reducing your risk of heart disease and diabetes as well as aiding and maintaining weight loss.

Juscelino Tovar, an author of the study, said that one important benefit of the lower GI blue tortillas is their potential role in preventing or controlling metabolic syndrome, a combination of disorders which increase the risk of heart disease, stroke and diabetes.

NB The blue colouring is due to the presence of anthocyanins in the corn. These are the same health promoting compounds found purple berries and red wine.