A new study claims that falling consumption of salt in recent years has been the key factor in a large drop in the number of people dying from a heart attack or stroke in England.
According to the research findings, a 15% drop in average daily consumption of salt contributed significantly to fewer stroke and coronary heart disease fatalities between 2003 and 2011.
The study, published in the medical journal BMJ Open, suggests that over this time period there were 42% fewer stroke fatalities and a fall of 40% in people dying from coronary heart disease.
The researchers claim that falling levels of salt consumption were "an important contributor" to falls in blood pressure over the eight-year period. The authors of the study said: "As a result, the decrease in salt intake would have played an important role in the reduction of stroke and ischaemic heart disease mortality during this period.”
Between 2003 and 2011 average salt intake fell by 15%, from 9.5g a day to 8.1g a day. Over the same time period, mortality rates dropped from 134 to 78 (42% down) per 100,000 population from stroke, and from 232 to 139 (40% down) per 100,000 population for coronary heart disease.
Deaths from cardiovascular disease in the UK have more than halved since 1971, falling from 335,000 to 161,000 in 2012. The Food Standards Agency (FSA) has made efforts in recent years to convince food manufacturers to gradually reduce the amount of salt they add to their products.
The study also found that several other risk factors for cardiovascular disease also declined during the study period, including average cholesterol and smoking. However average weight as measured by Body Mass Index rose, as did fruit and vegetable consumption.
The authors analysed various official sources of health and lifestyle data, including several years of the Health Survey for England and the national diet and nutrition survey, which gauged salt levels through analysing urine samples.
Some experts suggested that the new paper overplayed the extent to which declining salt intake could be credited with the fall in heart attack and stroke deaths. "Plausibility of assumption does not equal evidence," said Patrick Wolfe, professor of statistics at University College London.