Salt lovers on a slippery slope
Links between high blood pressure and salt intake have been made for the first time in Australians.
A study of 783 older Australians by Deakin University and the Cancer Council Victoria found those who ate large amounts of salt were twice as likely to have high blood pressure.
While various overseas studies have made links between salt intake and blood pressure, it is the first time an Australian study has demonstrated the association.
Those who took part in the study had urine samples analysed for sodium and potassium levels, which indicate daily dietary salt intake.
They had their blood pressure recorded and were asked how much salt they used in cooking and at the table.
Most participants ate excessive amounts of salt, with just five per cent sticking to the recommended limit of four grams a day.
Those with the highest amounts of sodium in their urine were twice as likely to have high blood pressure as those with the lowest levels.
More than 40 per cent of the group were classified as hypertensive (high blood pressure).
They tended to be older, aged about 64, have a higher body mass index and higher sodium levels in their urine.
There were roughly equal numbers of people born in Australia, New Zealand, Italy and Greece who took part in the study.
Those born in Italy and Greece were more likely to cook with salt, which led to higher levels of sodium in the urine samples.
The study's authors described the results as concerning given that most people were aware they had high blood pressure but still ate large amounts of salt.
"Our findings provide supporting evidence that the current high intake of sodium in older adults in Australia is related to higher blood pressure," they wrote in the study, published by the Medical Journal of Australia.
"Most participants were consuming excessive amounts of sodium, which appears to be making a significant contribution to elevated blood pressure and increased rates of hypertension.
"These results suggest that a population-wide reduction in sodium intake could be effective in reducing blood pressure in adults in Australia."
An estimated one third of Australians have high blood pressure, which is one of the most common and preventable risk factors for cardiovascular disease.
Those who lower their blood pressure can reduce their chances of dying from a stroke by 10 per cent and of developing ischaemic heart disease by seven per cent.
But the researchers said it was difficult for people to reduce their salt intake because more than three quarters of their sodium intake was already in manufactured food.
"The most effective strategy to achieve a significant reduction in population-wide salt intake would be to reduce the salt added to staple processed food," they said.