Heart Health: 'Too Much or Too Little Salt Could Increase Cardiovascular Risk'

Two studies published this week in the New England Journal of Medicine offer conflicting evidence about how much salt we should be consuming.

The Tufts University study, which covered populations across 187 countries, found that almost every adult on the planet consumes too much salt, with an average of 3.95 grams of sodium consumed per person per day - nearly double the World Health Organisation's recommendation of 2.0 grams.

Researchers say this excess salt intake is responsible for one in 10 deaths worldwide from various cardiovascular causes, which equates to around 1.6 million deaths every year.

Forty percent of the deaths were found to occur before the age of 70 and 84% took place in low and middle-income countries.

"We found that four out of five global deaths attributable to higher than recommended sodium intakes occurred in middle- and low-income countries," said John Powles, an academic from the University of Cambridge who co-authored the study. "Programs to reduce sodium intake could provide a practical and cost effective means for reducing premature deaths in adults around the world."

The Tufts authors acknowledge that their results based on urine samples may underestimate actual sodium intakes.

The findings are published in the August 14 issue of The New England Journal of Medicine.

However, there seems to be some disagreement on what constitutes excessive salt intake and whether it is bad for your health. Canadian researchers believe that in fact, anything less than 3 grams could be damaging.

Low salt intake increases cardio risk, say Canadian scientists

In the same edition of the journal, another study led by investigators at McMaster University found that with ingested daily sodium levels between 3 and 5 grams, there was a lower risk of cardiovascular events and death, compared with either a higher or lower level of salt in the diet.

In people whose average daily sodium intake was less than three grams, the Prospective Urban Rural (PURE) study found an elevated risk of heart attack, stroke and other cardiovascular problems, reported The Canadian Press. It also showed that a dietary sodium level exceeding five grams per day did raise blood pressure, "especially among people who already have hypertension and those age 55 and older."

The Pure study suggests that it would be best to neither reduce nor increase salt intake from a "modest" 3-5 grams. C ardiologist Dr. Salim Yusuf also advised increasing potassium intake by eating bananas, avocados, sweet potatoes, green leafy vegetables and legumes.

A balanced approach to diet was heralded by the researchers, who recommended combining a moderate salt intake with fruit and vegetables to keep the heart healthy for longer.