* Review's findings inconclusive, prompt criticism from
* WHO recommends cutting salt consumption for better health
* Researchers say larger studies needed to assess benefits
(Updates throughout with reaction from experts)
By Kate Kelland
LONDON, July 6 In an analysis that set off a
fierce debate over the health effects of salt, researchers said
on Wednesday they had found no evidence that small cuts to salt
intake reduce the risk of developing heart disease or dying
In a systematic review published by The Cochrane Library,
British scientists found that while cutting salt consumption did
appear to lead to slight reductions in blood pressure, that was
not translated into lower death or heart disease risk.
The researchers said they suspected the trials conducted so
far were not big enough to show any benefits to heart health,
and called for large-scale studies to be carried out soon.
"With governments setting ever lower targets for salt intake
and food manufacturers working to remove it from their products,
it's really important that we do some large research trials to
get a full understanding of the benefits and risks of reducing
salt intake," said Rod Taylor of Exeter University, who led the
The Cochrane review attracted sharp criticism from nutrition
experts. Francesco Cappuccio, head of the World Health
Organisation's collaborating centre for nutrition at Warwick
University, said it was "a surprisingly poor piece of work".
"This study does not change the priorities outlined
worldwide for a population reduction in salt intake to prevent
heart attacks and strokes, the greatest killers in the world,"
he said in an emailed comment.
Simon Capewell, a professor of Clinical Epidemiology at
Liverpool University, said the review was "disappointing and
inconclusive" and did not change public health consensus that
dietary salt raises blood pressure.
Most experts are agreed that consuming too much salt is not
good for you and that cutting salt intake can reduce
hypertension in people with normal and high blood pressure.
Many developed nations have government-sanctioned guidelines
calling on people to cut their salt or sodium intake for the
sake of their longer-term health. The World Health Organisation
(WHO) lists reducing salt intake among its top 10 "best buys"
for reducing rates of chronic disease.
In Britain, the National Institute of Health and Clinical
Guidance (NICE) has called for an acceleration of the reduction
in salt in the general population from a maximum intake of 6
grams(g) a day for adults by 2015 to 3g by 2025.
U.S. guidelines recommend Americans consume less than 2.3g
of salt daily, or 1.5g for certain people who are more at risk
for high blood pressure or heart disease.
While previous trials have found there is a blood pressure
benefit from cutting salt, research has yet to show if that
translates into better overall heart health in the wider
population. High blood pressure, or hypertension, is a major
risk factor for cardiovascular diseases -- the leading causes of
Taylor said he thought it did not find any evidence of big
benefits because the numbers of people studied and the salt
intake reductions were relatively small.
"The people in the trials we analysed only reduced their
salt intake by a moderate amount, so the effect on blood
pressure and heart disease was not large," he said.
For this review, Taylor's team found seven studies that
together included 6,489 participants. This gave the researchers
enough data to be able to start drawing conclusions, they said.
But even so, the scientists think they would need to have data
from at least 18,000 people before they could expect to identify
any clear health benefits.
Elaine Rush, a professor of nutrition at Auckland University
of Technology in Australia, said that putting a spotlight on
single trials and generalising dietary advice for a single
nutrient such as salt was "not helpful".
"What is helpful is for the food industry to reformulate
products to reduce sodium and increase the nutrient quality of
foods by using real ingredients," she said in an emailed
(Editing by Jon Hemming)