WELLINGTON, New Zealand (AP) — Experts say a New Zealand woman’s 2-gallon-a-day Coca-Cola habit probably contributed to her death. The soft-drink giant has responded by noting that even water can be deadly in excessive amounts.

Natasha Harris was a 30-year-old mother of eight from Invercargill who died of a heart attack in 2010. Fairfax Media says a pathologist testified Thursday that she probably suffered from hypokalemia, or low potassium, which was caused by excessive consumption of Coke and overall poor nutrition.

Harris’ partner says she drank up to 10 liters (2.6 gallons) of regular Coke every day. He also says she ate little and smoked about 30 cigarettes a day.

The coroner’s office is compiling a final report on Harris’ death. A Coca-Cola spokeswoman says its products are safe.