Plain packaging of cigarettes reduces their brand appeal much more than gory health warnings, no matter how large they are, a new study has found.

Professor Melanie Wakefield, of Cancer Council Victoria, and colleagues, report their findings in the journal Addiction.

"Larger graphic health warnings are harder to ignore," says Wakefield. "But they could be undermined by colourful and creative branding design that remains on a relatively small part of the pack. So we really wanted to have a face off experiment."

Based on current global smoking patterns, annual tobacco deaths will rise to 10 million by 2030, say Wakefield and colleagues.

In an attempt to curb such deaths, Australia is set to become the first country to mandate packaging of cigarettes in plain olive green packs, and to increase the size of gory pictorial health warnings.

"From a larger public health perspective the aim of plain packaging is to reduce the appeal of branding — to make the health warnings stand out more," says Wakefield.

A number of countries are lodging opposition to the plans with the World Trade Organization.

Brand power

Wakefield and team wanted to look at the relative importance of health warnings and plain packaging on the appeal of cigarette brands.

They asked 1,200 smokers to rate online images of packs of six popular brands of cigarette.

The smokers were randomly assigned to different packaging conditions to compare the impact of branded packs, plain packaging, and different-sized pictorial health warnings.

Wakefield says the findings confirmed previous studies that compared the impact of branded versus plain packaging.

"Smokers viewed plain packs to be less attractive than branded packs. They thought they would be smoked by people with less desirable characteristics — people who were less trendy, less successful or more boring," she says.

"Smokers who viewed plain packs also thought the cigarettes would be less satisfying and enjoyable to smoke than those who viewed branded packs."

The researchers also found increasing the size of graphic health warnings reduced the appeal of packs, but not as much as plain packaging did.

"Overall we found that plain packaging reduced elements of brand appeal much more than increasing the size of graphic health warnings," says Wakefield.

Purchase plans

In a second part of the study the researchers looked at the impact of packaging on the purchase intentions of smokers.

Smokers were presented with an array of packs to choose from, on the assumption they had run out of cigarettes.

They were less likely to buy cigarettes in plain packs, and this was not affected by the size of health warnings, says Wakefield.

But, she says, graphic health warnings are still important for communicating the serious harms of smoking.

British American Tobacco says the research was undertaken while branded packs were still in the marketplace, before plain packaging became law.

Spokesman Scott McIntyre says the company's own figures show consumers have not changed their purchasing behaviour since the implementation of plain packaging last year.

With files from the Australian Broadcasting Corporation