1 ADDITIONAL SLIDES Excess Dietary Sodium: Impact on Hypertension and Health Outcomes Updated 2011

2 The physiology of sodium- mediated hypertension: a primer

3 Animal studies suggest: Van Vliet et al, 2006 Excess sodium intake can cause a slow and progressive increase in BP. In time, sodium restriction may not fully restore BP to original levels. Acute sodium restriction may underestimate the accumulated effects of lifelong sodium exposure.

4 Animal studies: summary 1.The ability of excess sodium to raise BP is a general characteristic of mammals, including humans. 2. The effects of sodium on BP are complex, having several distinct components: - Acute vs Slow-Progressive - Reversible vs Irreversible 3. Many individual systems and mechanisms contribute to the effect of sodium on BP.

5 Renal mechanisms for sodium-dependent hypertension Acute high sodium intake - Renal retention of fluid   BP Chronic high sodium intake - Resets renal threshold for sodium excretion  less sodium excretion -  Peripheral resistance - Subnormal vasodilation to sodium load Nat. Med :64

6 Sodium sensitivity of BP sodium sensitivity is well defined by the steady state relationship between sodium intake and BP (“chronic pressure natriuresis relationship”, or “renal function curve”).

7 Intrauterine growth retardation (IUGR) Low nephron mass Renal disease  Inflammation, injury, etc Genetic abnormalities Exogenous agents (e.g. DOCA) Ageing  sodium excretion Factors that lead to sodium- sensitivity of blood pressure

8 Sodium in our food: why? Boosts flavor, texture and shelf life of foods Salt and sodium phosphates increase water binding capacity of meat products Salty snacks make you thirsty!

9 Average “hidden" sodium Intake by provinces

10 + Sodium usual intake distribution for men and women Results are based on the Canadian Community Health Survey - Cycle 2.2 on Nutrition, Statistics Canada, Usual intake distributions were estimated using the Software for Intake Distribution Estimation (SIDE), Iowa State University, 1986 Age (y) MenWomen % above AI% above UL% above AI% above UL 19 to to CCHS 2.2 Statistics Canada, 2004

11 The sodium intake of most Canadians adults exceeds the UL Health Reports, Vol. 18, No 2, May 2007 Upper Limit % above UL

12 Hidden sodium intake and salt added at the table Add salt to food at table 2,927 3,074 3,182 3,396 * * “Hidden“ sodium intake * Average “ hidden” sodium intake Health Reports, Vol. 18, No 2, May 2007

13 Salt use by hypertensive adults Add salt to food at table Canadians age >30 years diagnosed with high blood pressure Never Rarely Occasionally Very often * * * % of respondents Health Reports, Vol. 18, No 2, May 2007

14 Sodium and Blood Pressure: Intersalt BMJ July 30; 297(6644): 319–328

15 Relationship between sodium intake and fluid consumption in children/adolescents R=0.40 p<0.001 He et al Salt Intake, Soft Drinks, and Obesity in Children, Hypertension. 2008;51:

16 Sodium in our Diet Natural ~15% Discretionary ~15% Manufactured food processing ~70% Adequate Intake* 1,500 mg/d (3.8 g salt) Tolerable Upper Intake* 2,300 mg/d (5.8 g salt) Reference Standard** 2,400 mg/d (6.1 g salt) 3,000 – 4,000 mg/d (8-10 g salt) *Health Canada. Dietary Ref. Intake Reports **2003 labeling legislation

17 The sodium intake of most Canadian children/youth exceeds the UL Health Reports, Vol. 18, No 2, May 2007 Upper Limit 1500mg % above UL

18 Av. Sodium Intake* (mg/day) of Canadian Children and Youth *Does not include sodium added at the table or during home cooking Ref: Canadian Community Health Survey, Nutrition Survey yr4-8 yr9-13 yr14-18 yr MaleFemaleM&F

19 The sodium intake of most Canadian children/youth exceeds the UL Health Reports, Vol. 18, No 2, May mg Upper Level % above UL yr4-8 yr9- 13yr14-18 yr Male Female M & F

20 Sodium restriction reduces BP in children and infants Meta-analysis Results: Children (average age 13)  Reduced dietary sodium 42%  Reduced BP 1.17/1.29 mmHg Infants (less than one year)  Reduced dietary sodium 54%  Reduced SBP 2.47 mmHg Hypertension 2006;48:861-9

21 High sodium intake may also be a risk factor for obesity ! High dietary sodium increases thirst and fluid consumption Many of the fluids consumed contain simple sugars or alcohol and contribute to caloric intake 20-30% of the excess calories consumed by children and adolescents are through increased beverage consumption associated with high sodium intake Therefore high sodium diets are likely to be a significant factor in the obesity epidemic He et al Salt Intake, Soft Drinks, and Obesity in Children, Hypertension. 2008;51:

22 Our taste for salt: would we miss it ? Taste buds get used to high salt levels As salt levels are gradually reduced taste buds adapt Only takes a few weeks to enjoy food with less salt and reveal subtle flavors

23 Sodium reduction interventions are as effective as smoking cessation interventions in saving lives Deaths (millions) The Lancet, Volume 370, Issue 9604, , December 2007

24 Deaths averted by implementation of tobacco and sodium interventions by type of diseases Deaths (%) 75,6% 15,4% 8,7% The Lancet, Volume 370, Issue 9604, , December 2007

25 Treatment Study: DASH Sodium Control diet - low in fruit, veg and dairy, fat content typical of US DASH diet - high in fruit, veg and low-fat dairy, reduced fat content Consume diet for consecutive 30 day periods in random order at each of 3 levels of salt NEJM 2001; 344:3-10 InterventionChange in mean B.P. vs. control (systolic) Control dietDASH diet 9g/d saltControl level- 6 mmHg 6g/d salt- 2 mmHg- 7 mmHg 3g/d salt- 7 mmHg- 9 mmHg -7 Randomized 412 adults (mixed B.P. status, racial groups, sexes) to: -7 (NT) -11(HT)

26 Effects of sodium reduction on BP over time Obarzanek, E et al. Hypertension 2003; 42: DASH Data:

27 Sodium substitution: a low-cost strategy for blood pressure control among rural Chinese: A randomized, controlled trial RCT of 12 months; n = 608 Sodium Substitute (65% NaCl, 25% KCl, 10% MgSO4) compared to normal salt (100% NaCl) Mean age = 60; 56% ♀ ; Mean BP = 159/93 Mean SBP drop = 3.7 mm Hg (p  0.001) No difference in DBP Sodium Reduction for the Treatment of Hypertension J Hypertension 2007, 25 (10)

28 Sodium Reduction for the Treatment of Hypertension No difference in groups for food taste (saltiness) J Hypertension 2007, 25 (10)

29 What is happening in Canada Hypertension Canada  Developed the policy statement on dietary sodium for Canadians Hypertension Canada – Canadian Hypertension Education Program Sodium Committee  Develops materials to support public education  Develops materials to support health care professional education

30 What is happening in Canada Sodium Strategic Planning Committee –Canadian Society of Nephrology –Dietitians of Canada –Canadian Stroke Network –Blood Pressure Canada –Canadian Hypertension Society –Heart and Stroke Foundation of Canada –Canadian Council of Cardiovascular Nurses –Canadian Cardiovascular Society (Observer Public Health Agency of Canada)  Assisted BPC in Policy Statement development re the need to reduce dietary sodium  Guidance for Strategy and Tactics to reduce dietary sodium

31 What is happening in Canada Canadian Stroke Network –“Salt Lick” award for very high sodium foods –Sodium 101 website for Canadian information on dietary sodium –Media releases on issues relating to dietary sodium of interest to Canadians Heart and Stroke Foundation of Canada –Health Check program with increasingly strict criteria of sodium content of food. –Media releases on issues relating to dietary sodium of interest to Canadians

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33 Canada takes action Multi-stakeholder Working Group formed by Heath Canada to oversee a reduction in dietary sodium In the news: Heath Minister Tony Clement says sodium is a bigger health threat than artery-plugging trans fats. “It’s almost become a silent invader of our food supply, and only now are we seeing the consequences of it.” CanWest News Service – Oct. 26, 2007.

34 Many organizations have concluded that high dietary sodium increases blood pressure and is a health risk World Health Organization United Kingdom and most European Governments The Institute of Medicine The American Heart Association The American Public Health Association Blood Pressure Canada (BPC) Canadian Association of Cardiac Rehabilitation (CACR) Canadian Cardiovascular Society (CCS) Canadian Council of Cardiovascular Nurses (CCCN) Canadian Diabetes Association (CDA) Canadian Heart Failure Network (CHFN) Canadian Hypertension Society (CHS) Canadian Medical Association (CMA) Canadian Nurse Association (CNA) Canadian Pharmacists Association (CPA) Canadian Public Health Association (CPHA) Canadian Society of Internal Medicine (CSIM) Canadian Stroke Network (CSN) College of Family Physicians of Canada (CFPC) Dietitians of Canada (DC) Heart and Stroke Foundation of Canada (HSFC) The Kidney Foundation of Canada

35 What is happening in Canada Food Sector ( via Food and Consumer Products of Canada ) –Agreed to collaboration with the health sector and government –With Blood Pressure Canada requested Heath Canada involvement and oversight of the effort to reduce dietary sodium –More food choices low in sodium –More advertising of low sodium foods –Low – no sodium seasoning alternatives –Leadership from some companies (e.g. Campbell's Soup)

36 What is happening in Canada Processed food and beverage products sector Food and Consumer Products of Canada (FCPC) and BPC worked with Health Canada To establish the multi-stakeholder Working Group on Sodium Reduction (WG) Mandate of the WG is: To develop and oversee implementation of a strategy to lower sodium content in the diets of Canadians to within the range recommended in the IOM Dietary Reference Intakes (DRI) Report

37 What is happening in Canada Along with FCPC six other food industry trade associations are involved in the WG: –Baking Association of Canada –Dairy Processors of Canada –Canadian Council Grocery Distributors –Canadian Meat Council –Food Processors of Canada –Canadian Restaurant & Foodservice Association

38 What is happening in Canada Federal Government  Commissioned revised Dietary Reference Intake on sodium (2004)  Canadian Community Health Survey (nutrition) 2004, Prioritized sodium analysis (Health Reports 2007;18:47-52)  Importance of dietary sodium Hon S Fletcher at World Hypertension Day May 2007  Intersectoral Work group to oversee the lowering of dietary sodium Oct 2007  Public Health Agency of Canada Grant to develop educational material, May 2008  Public Health Agency of Canada indirect support for health sector (commissioning reports and assisting with meeting logistics) 2006 to date

39 What is happening in Canada Provincial Governments  Several provincial governments are examining policies to limit high sodium foods within provincial jurisdiction (e.g. schools)

40 What is happening in Canada Media Strong interest in media releases from the Canadian Stroke Network, Heart and Stroke Foundation of Canada, World Action on Salt and Health Initiation of World Action on Salt and Health Salt intake and blood pressure in children Blood Pressure Canada Sodium policy Statistics Canada release of sodium consumption by Canadians Effects of high dietary sodium on hypertension in Canada Effects of high dietary sodium on cardiovascular disease in Canada International comparison on the vastly different sodium content of the same foods in different countries- For several products Canada had the highest amount of sodium added to their food. Canadian Stroke Network Salt Lick Award Government of Canada announcement of Intersectoral Work Group to lower dietary sodium

41 Reducing Canadians’ sodium intake Most dramatic impact will be to reduce hidden sodium in manufactured foods Reduction can be achieved by: –Gradual reduction of sodium by food manufacturers and restaurateurs –A public campaign on health benefits of sodium reduction –Raising consumer attention to sodium levels on food labels

42 Anticipated Outcome Increased consumer awareness of the health dangers of high dietary sodium Increased consumer demand for lower sodium foods Increased development of lower sodium foods by the food sector Increased monitoring of dietary sodium as a health parameter by the government Gradual reduction in dietary sodium such that most Canadians are below the upper limited (2020)

43 Resources

44 Resources WHO Forum on Reducing Salt Intake in Populations (2006:Paris,France) Reducing salt intake in populations: report of a WHO forum and technical meeting, 5-7 October 2006, Paris, France 1.Sodium chloride, Dietary – adverse effects 2.Hypertension – prevention and control 3.Iodine – deficiency 4.Nutrition policy 5.National health programs – organization and administration I.World Health Organization II.WHO Technical Meeting on Reducing Salt Intake in Populations (2006: Paris, France) III.Title ISBN (NLM classification: QU 145)

45 Resources Online Mail, Telephone, Fax & TSO PO Box 29, Norwick NR3 1GN Telephone orders/General enquiries: Order through the parliamentary Hotline Lo-call Fax orders: Textphone

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