Coca-Cola and food should be added to an international list of addictive substances so that people can get better treatment, the National Addiction Centre's director says.
The partner of Invercargill mother-of-eight Natasha Harris said at an inquest into her death yesterday that she drank up to eight litres of Coke a day.
Professor Doug Sellman of the National Addiction Centre believed the Coke contributed to the 30-year-old's death, but said something good could come from the "tragedy".
He said there were many people addicted to food, which included Coke, and who had died as a result of their addictions. Their deaths were usually associated with obesity and Ms Harris' death was the first he had heard of where Coca-Cola might be a contributing factor.
But there weren't many health services that catered for people with food addictions, Sellman said.
The American Psychiatry Association's manual on addictions only included gambling, alcohol and drugs, including caffeine and tobacco, and addiction services in New Zealand were really only trained to help people with those addictions.
Sellman hoped food, electronic gaming and sex would be included in the list of addictions in the next couple of years.
"It will allow addiction services to see a broad range of people with compulsive disorders," Sellman said.
He said it had taken a while for health professionals to accept people could be addicted to food, and he used to be reluctant to call people "food addicts".
"A few years ago I wasn't necessarily convinced, but now I'm totally convinced."
Harris died on February 25, 2010.
Otago-Southland coroner David Crerar did not make any preliminary findings after yesterday's inquest, but pathologist Dan Mornin said he believed Harris died of cardiac arrhythmia and it was likely she was suffering from hypokalemia (low potassium) along with caffeine toxicity, which could have contributed to her death.
Mornin said Coca-Cola along with poor nutrition and caffeine had probably contributed to her death, and Sellman agreed.
Sellman said there were three reasons why people became addicted to things, whether it was alcohol, food, sex or gambling.
Family history, whether someone was a risk-taker and extrovert and whether they got pleasure from what they were doing were the three main components.
People needed to find an activity pleasurable to want to repeat it. If they repeated it enough, it would become a habit, which could then become an addiction.
"As they're doing that there are genetic switches that change free will into a dehumanised state of drug craving and compulsion."
Christchurch-based researchers at the University of Otago developed a new list of 49 foods people should avoid and published their findings in the New Zealand Medical Journal earlier this year. The list is of the most addictive foods, Sellman said.
The foods were energy and calorie dense, high in fat and/or added sugars, prepared using a high fat cooking method such as frying or roasting, or low in essential nutrients.
They included muesli bars, ice cream, cakes, chocolate, doughnuts, jam, honey, pies and pastries. Energy drinks, cordial and fruit drinks also made the list.
A lawyer for Coca-Cola Amatil New Zealand said at Ms Harris' inquest there was no basis for a finding that her excessive consumption contributed to her death. The medical evidence indicated it was a possibility, not a probability.
After the inquest, Coca-Cola Oceania public affairs and communication manager Karen Thompson said the safety of its products was paramount.
''The grossly excessive ingestion of any food product, including water, over a short period of time with the inadequate consumption of essential nutrients, and the failure to seek appropriate medical intervention when needed, can be dramatically symptomatic . . . we believe that all foods and bevedhrages can have a place in a balanced and sensible diet combined with an active lifestyle.''