Cutting salt intake key to preventing stroke deaths: Study

LONDON — Declining consumption of salt in recent years has been the key factor in the large fall in the number of people dying from a heart attack or stroke, research published on Monday shows.

A 15 per cent fall in average daily consumption of salt in England between 2003 and 2011 played an important role in the 42 per cent fewer stroke fatalities and 40 per cent drop in those dying from coronary heart disease, said the study published in the medical journal BMJ Open.

The researchers, who include Britain’s leading campaigner against added salt in food, claimed that diminishing levels of salt had been an important contributor to falls in blood pressure over the eight-year period.

“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,” said the authors.

Deaths from cardiovascular disease in the UK have more than halved since 1971, falling from 335,000 to 161,000 in 2012. Between 2003 and 2011, mortality rates from stroke dropped from 134 to 78 (42 per cent) per population of 100,000 and those from coronary heart disease fell from 232 to 139 (40 per cent) per population of 100,000.

Average salt intake decreased from 9.5g a day to 8.1g a day (15 per cent) in the eight-year period, largely due to efforts by the Food Standards Agency in persuading food manufacturers to gradually reduce the amount of salt they add to their products.

The authors acknowledged that levels of several other risk factors for cardiovascular disease also declined during the study period, including average cholesterol and smoking, although average weight as measured by Body Mass Index rose, as did the consumption of fruit and vegetables.

They reached their conclusions after analysing 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 used urine samples to gauge salt levels.

However, 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.

Professor David Spiegelhalter at Cambridge University cited the researchers’ admission that the fall over that time in systolic blood pressure would be expected to reduce strokes by only 11 per cent and heart attacks by 6 per cent — small amounts of the total falls. Reduced blood pressure did not represent the authors’ claimed “substantial contribution” to reduced death rates. THE GUARDIAN