A mandatory curb on the amount of salt allowed in processed foods could be 20 times more effective than a voluntary industry curb, a new Australian study suggests.

University of Queensland researchers examined the public health benefits and cost effectiveness of strategies to reduce the amount of salt in food, a factor known to have a key role in increasing risk of heart disease and stroke.

They compared the effects of mandatory and voluntary salt reductions on years of good health over a lifetime, and the savings these reductions would mean for long-term health care costs.

To measure the effect of voluntary reductions — those that food manufacturers have the option of adopting — they looked at the Australian "Tick" program, which allows manufacturers to buy the right to put an endorsement logo on their product packaging if they reduce the salt content of their products.

The researchers found the voluntary "Tick" program was cost-effective, and would cut heart disease by almost 1 percent.

However, they found government-imposed mandatory limits would reduce heart disease by 18 percent.

To calculate the long-term health care costs each type of limit would bring, the researchers took into account the salt reductions in a number of common foods (including bread, margarine and cereal), the amount of these products sold, the average consumption of the products by consumers, the costs for enforcing legislation and the impact of dietary advice from health-care experts.

The researchers found the population would gain 610,000 years of healthy life if the mandate forced everyone to reduce their salt intake to the recommended limits of 6 grams maximum a day.

Salt is a cheap ingredient for food manufacturers to put in food, and is not essential at such high levels, the authors said in the study.

The study was published Nov. 1 in the journal Heart.

This article was provided by MyHealthNewsDaily, a sister site to LiveScience.