Coca-Coca Enterprises boss John Brock says detractors 'don't understand' how safe aspartame is, and insists that diet soda sales remain strong - growth for Coke Zero offset a 5.5% full year volume slide for Diet Coke. His comments came against the backdrop of CCE's full year 2014 results - that revealed flat volume sales, with 6.5% growth in energy drinks, 5% growth in waters - led by Chaudfontaine and Smartwater in Great Britain - offsetting a 0.5% decline in sparkling soft drinks, where classic Coke sales down 0.5% contributed to a decline across the brand portfolio.