Emerging markets are set to drive growth of functional drinks sales over the next four years, according to new research.

Functional drinks sales grew by an average 8% annually in volume terms between 2003 and the end of 2008, global drinks consultancy group Zenith International said yesterday (22 December).

Sales slowed in 2008, rising 3% to 26.5bn litres, due to a "substantial slowdown" in North America, said Zenith. North America constituted 41% of the global functional drinks market by volume in 2008.

However, medium-term prospects for the global market remain bright and emerging markets are set to drive growth.

North America's dominance in sports drinks is likely to be eroded as Asia Pacific and Latin America see their sales expand, said Zenith. Meanwhile, energy drinks sales are set for strong growth in the Middle East.

Global functional drinks sales are set to hit 35bn litres by 2013, said the group.