Health experts say the death of an Invercargill woman which has been linked to her excessive Coca-Cola consumption shows tougher regulation is needed.
Natasha Harris, 31, died in February 2010 from cardiac arrhythmia. Otago-Southland coroner David Crerar said in a finding published on Tuesday the death was probably related to her drinking up to 10 litres of Coke a day.
The coroner has recommended warning labels about the amount of sugar and caffeine be put on all bottles, and has also asked the Health Ministry to consider lowering caffeine limits.
The coroner's call is backed by Professor of Nutrition at Auckland University of Technology, Elaine Rush, who says despite a massive rise in the number of caffeinated products, little is known about the drug's long-term health effects.
Professor Rush says laboratory results at AUT shows individuals have completely different reactions to caffeine, and it is likely many bad reactions go unreported.
The director of the National Addiction Centre, Professor Doug Sellman, says lack of regulation leaves vulnerable individuals at the mercy of predatory marketing.
Coca-Cola said it was disappointed the coroner has blamed Ms Harris' excessive consumption of Coca-Cola, together with other health and lifestyle factors, as the probable cause of her death.
It said a South African pathologist hired by the company told the inquest a number of factors, including diabetes, could have caused the fatal heart irregularity.
And a group representing the soft drinks industry says the coroner's recommendation for more warning labels is unnecessary.
Juice and Beverage Association executive director Kerry Tyack said it is up to individuals to take responsibility for their nutrition and practice moderation.
Mr Tyack said New Zealand and Australia already have very strict regulations on caffeine levels in drinks compared with other countries.
Food and Grocery Council chief executive Katherine Rich said that to suggest labelling would have made a difference in this case is unfair.
"To seek labelling on products that contain caffeine which are most often consumed in moderation would not be good regulation for New Zealand."
Caffeine regulation review
The Ministry for Primary Industries says the coroner's recommendations will be considered as part of the current trans-Tasman review of the policy on caffeine in foods. Public consultation on the review is due to take place in April.
Caffeine, particularly in energy drinks, has come under increasing scrutiny in recent months, with the United States Food and Drug Administration launching an inquiry into the safety of Monster Energy drinks after reports of five deaths there.
The New Zealand National Poisons Centre received 82 calls related to caffeine products between February 2005 and December 2009.
A toxicologist at the Dunedin centre, Dr Leo Schep, says high caffeine consumption has been implicated in other cases of heart arrhythmia, including among high performance athletes taking supplements.