Slapping a fat tax on butter and other fatty Kiwi staples could spare hundreds of New Zealanders from developing heart disease, new research shows.
A breakthrough study has proven that switching just five per cent of daily energy intake from saturated fats to polyunsaturated fats decreases heart disease by 10 percent.
It's the first New Zealand study to show that a relatively small dietary change can deliver a potentially huge health benefit.
The Otago University researchers, enthused by their findings, say the results are strong enough to justify taxing foods that are high in sugar, salt and saturated fat to change purchasing patterns in supermarkets.
However, various health experts say the benefits of such a strategy are unproven and may just push shoppers towards other cheap, less healthy alternatives.
The research team analysed data from several international studies examining the links between fat intake and heart disease, which affects 300,000 New Zealanders.
Applying their findings to a typical Kiwi diet, they found substantial benefits by switching red meat for canned tuna, cheese for nuts and butter for canola oil.
Professor Nick Wilson, who co-wrote the study published in the Australian and New Zealand Journal of Public Health, said given the level of health benefit, it could be wise for the government to follow Denmark, where butter consumption has dropped 15 per cent thanks to a fat tax.
Alternatively, introduce a tax on soft drinks as in France, Prof Wilson said.
The millions in tax revenue could be funnelled into health programmes to make it easier and cheaper for kids and low incomer earners to get fruit and vegetables, he suggests.
But Professor Lynnette Ferguson, head of nutrition at Auckland University's School of Medical Sciences, rejected the authors' tax suggestions, saying there was still little proof lifting prices changed buyer behaviour.
Professor Cliona Ni Mhurchu, who runs the university's National Institute for Health Innovation, agreed, saying it was possible shoppers would just swap to other cheaper untaxed products that might be even worse for their health.
She and another leading nutritionist, Professor Elaine Rush of Auckland University of Technology, suggested other measures, such as front-of-pack labelling being trialled in Australia, could bear better results.
Prof Rush said government regulations could also be used to control which fats fast food outlets and commercial bakers use in their products.