The world's largest chocolate maker says it may have come up with a chocolate bar that could fight wrinkles and slow the ageing process, making it the latest food group to tap the appetite for healthier living.

Eating 20 grams (0.755 oz) of specially developed chocolate packed with antioxidants, or flavanols, each day may help prevent wrinkles and make skin more radiant by boosting elasticity and improving hydration, studies carried out by Barry Callebaut showed.

Consumers are becoming increasingly aware of the nutritional value of what they eat, and Barry Callebaut's claims come as food giants such as Nestle and Danone  also push into the healthy eating arena.

Dark chocolate has already been linked with certain health benefits, such as helping to lower blood pressure and reducing the risk of strokes thanks to its high content of antioxidants.

The Swiss group has developed a way of preserving the flavanols found in cocoa beans during the chocolate-making process, allowing them to produce a bar that is richer in flavanols, Barry Callebaut Chief Innovation Officer Hans Vriens said in an interview.

"Chocolate and health do not seem to fit together but it is a very interesting proposition: if I can eat something I like and it is good for me, that is great," Vriens said.

"Chocolate is probably at the bottom of the list when you think about making food healthier."

Smoking, pollution, caffeine and a lack of sleep contribute to the creation of free radicals that can damage healthy cells in the body and accelerate the ageing process.

"There is a huge body of evidence that shows flavanols slow down damage caused by free radicals," said Kepler Capital Markets analyst Jon Cox.

"Food manufacturing companies are leveraging health and wellness into various products and there is definitely a market for chocolate in health and wellness. We have already seen how this has worked in dairy products, with products like Danone's Actimel and Unilever's Benecol," Cox said.

The functional chocolate market, which includes organic and diet chocolate, is seeing double-digit growth, easily outpacing the 1-2 per cent growth currently seen in the rest of the chocolate market, Cox said.

But some experts are doubtful about the positive effects flavanols have on skin.

"There is quite a lot of evidence that cocoa flavanols have a positive effect on the blood flow. They could reduce blood pressure which could have a positive effect on cardiovascular diseases," said Richard Hurrell, Professor of Human Nutrition at the Swiss Federal Institute of Technology.

"The possible effects on skin and cognitive performance are less well established. There is evidence, but it is much less consistent. It may be that the effect on the blood flow is also what improves memory or skin health in some of the studies," Hurrell said. – Reuters