salt intake, sugar-sweetened soft drink consumption, and blood pressure
TRANSCRIPT
Accepted Manuscript
Salt Intake, Sugar-sweetened Soft Drink Consumption and Blood Pressure
Feng J. He , PhD Graham A. MacGregor , MD
PII: S0002-9149(14)01089-3
DOI: 10.1016/j.amjcard.2014.05.004
Reference: AJC 20452
To appear in: The American Journal of Cardiology
Received Date: 1 May 2014
Accepted Date: 6 May 2014
Please cite this article as: He FJ, MacGregor GA, Salt Intake, Sugar-sweetened Soft Drink Consumptionand Blood Pressure, The American Journal of Cardiology (2014), doi: 10.1016/j.amjcard.2014.05.004.
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Salt Intake, Sugar-sweetened Soft Drink
Consumption and Blood Pressure
In their interesting review article, Malik et al1 do not seem to consider the
underlying mechanism by which sugar-sweetened soft drink consumption is
associated with increased blood pressure. For instance, there is clear evidence for a
causal relation between salt intake and total fluid consumption,2 as well as sugar-
sweetened soft drink consumption,3 an important and very relevant point which Malik
et al failed to acknowledge. A carefully controlled metabolic study in adult humans
where salt intake was changed, has quantified the relation between the change in
salt intake and the subsequent change in fluid consumption.2 A study in 10,074 free
living individuals across the world showed an identical relation between usual salt
and fluid intake.2 An analysis of the National Diet and Nutrition Survey dataset
showed that, in free living children in Great Britain, the same relation held true.3
Similar findings have also been reported in the USA and Australia.4 5 There is,
therefore, no doubt that in humans, like other mammals, salt is a major drive to thirst
and, an increase in salt intake will increase the amount of fluid consumed, and if part
of this fluid is in the form of soft drinks, they will be increased proportionately. It is
therefore likely that the increased salt intake is, at least, partially responsible for the
increase in blood pressure and the increase in soft drink consumption. In other
words, the observed association between sugar-sweetened soft drink consumption
and blood pressure may be, in part, mediated by salt intake.
As Malik et al rightly pointed out, sugar-sweetened soft drinks are the largest
source of added sugar in our diet. Added sugar is a major hidden source of calories
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and contributes to obesity and type 2 diabetes.6-8 Some studies also suggest that the
role of sugar in soft drinks in obesity might be key because it provides no feeling of
satiation.9 It is well established that obesity is associated with an increased blood
pressure. Additionally, sugar in soft drinks stimulates insulin secretion which could
lead to sodium and water retention10 and, thereby, possibly increasing blood
pressure. The suggested mechanism for the links between salt intake, sugar-
sweetened soft drink consumption and blood pressure is shown in Figure.
Raised blood pressure throughout its range is a major cause of cardiovascular
disease, accounting for 62% of strokes and 49% of coronary heart disease.11 A
reduction in population salt intake which can easily be made by slowly reducing the
amounts of salt added to foods by the food industry, will lead to a reduction in
population blood pressure and cardiovascular mortality, as demonstrated in the UK12
and Finland.13 Furthermore, a reduction in salt intake will cause a reduction in sugar-
sweetened soft drink consumption and, thereby, a decrease in obesity and type II
diabetes.
Efforts to reduce soft drink consumption combined with a gradual reduction in
the amounts of sugar added to soft drinks will provide additional beneficial effects on
health. An action group (Action on Sugar)14 was recently set up with a mission to
achieve a gradual and sustained reduction in the amounts of sugar added to foods
and drinks, following a similar model to the UK salt reduction programme15 pioneered
by Consensus Action on Salt and Health (CASH).16 This model has become one of
the most successful nutritional policies in the UK since the Second World War,17 by
setting progressively lower salt targets for over 80 categories of foods for the food
industry to achieve within a certain time frame.15 As this is done slowly, people do
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not notice the difference in taste. A reduction in population salt and sugar intake,
even by a small amount, will have a major beneficial effect on health along with
major cost savings.
Feng J He, PhD.
Graham A MacGregor, MD
London, UK
1 May 2014
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1. Malik AH, Akram Y, Shetty S, Malik SS, Yanchou Njike V. Impact of Sugar-
Sweetened Beverages on Blood Pressure. Am J Cardiol 2014;113:1574-1580.
2. He FJ, Markandu ND, Sagnella GA, MacGregor GA. Effect of salt intake on renal
excretion of water in humans. Hypertension 2001;38:317-320.
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associated with total fluid and sugar-sweetened beverage consumption in US
children and adolescents aged 2-18 y: NHANES 2005-2008. Am J Clin Nutr
2013;98:189-196.
5. Grimes CA, Riddell LJ, Campbell KJ, Nowson CA. Dietary salt intake, sugar-
sweetened beverage consumption, and obesity risk. Pediatrics 2013;131:14-21.
6. Vartanian LR, Schwartz MB, Brownell KD. Effects of soft drink consumption on
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Steffen LM, Wylie-Rosett J, American Heart Association Nutrition Committee of
the Council on Nutrition PA, Metabolism, the Council on E, Prevention. Dietary
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sugars intake and cardiovascular health: a scientific statement from the
American Heart Association. Circulation 2009;120:1011-1020.
9. DiMeglio DP, Mattes RD. Liquid versus solid carbohydrate: effects on food intake
and body weight. Int J Obes Relat Metab Disord 2000;24:794-800.
10. Rocchini AP, Katch V, Kveselis D, Moorehead C, Martin M, Lampman R,
Gregory M. Insulin and renal sodium retention in obese adolescents.
Hypertension 1989;14:367-374.
11. World Health Report 2002: Reducing risks, promoting healthy life. Geneva,
Switzerland: World Health Organisation, 2002. www.who.int/whr/2002 (Accessed
3 June 2013).
12. He FJ, Pombo-Rodrigues S, MacGregor GA. Salt reduction in England from
2003 to 2011: its relationship to blood pressure, stroke and ischaemic heart
disease mortality. BMJ Open 2014;4:e004549.
13. Karppanen H, Mervaala E. Sodium intake and hypertension. Prog Cardiovasc
Dis 2006;49:59-75.
14. MacGregor GA, Hashem KM. Action on sugar--lessons from UK salt reduction
programme. Lancet 2014;383:929-931.
15. He FJ, Brinsden HC, Macgregor GA. Salt reduction in the United Kingdom: a
successful experiment in public health. J Hum Hypertens 2013:advance online
publication, 31 October 2013; doi:2010.1038/jhh.2013.2105.
16. Consensus Action on Salt and Health. www.actiononsalt.org.uk/ (Access verified
July 23, 2012).
17. Winkler JT. Obesity exposé offers slim pickings. BMJ 2012;345:e4465.
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Figure caption: Mechanism for the links between salt intake, sugar-sweetened soft
drink consumption and blood pressure (BP).
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Sodium and water retention
BP ↑↑↑↑
Calorie ↑↑↑↑
Soft drinks ↑↑↑↑
Salt Intake ↑↑↑↑
Gut sodium
absorption
Insulin ↑↑↑↑
Obesity ↑↑↑↑