Hypertension, Diet and Dietary Sodium in Canada.

Why is sodium reduction Controversial?

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Norm Campbell

Financial interests in sodium

• Salary support from HSF-CIHR to lead efforts to prevent and control hypertension

• Only recent salt based grant was a $25,000 one year grant (2012-2013) from the NCE Canadian Stroke Network to develop and implement a weekly med-line search and review on dietary salt

• I have received $750 to talk on unhealthy eating from a Internal Medicine meeting in 2013

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Academic interests

Professor of Medicine, Community Health Sciences and Physiology and Pharmacology, Libin Cardiovascular Institute, O’Brien Institute of Public Health at the University of Calgary

-HSFC CIHR Chair in Hypertension Prevention and Control-Chair of the Canadian Hypertension Advisory Committee (of national

health and scientific organizations) to lead the nongovernmental effort to prevent and control hypertension

-President of the World Hypertension League-Co-Chair of the PAHO/WHO Technical Advisory Group on

Cardiovascular Disease Prevention through Dietary Salt Reduction-Member of the WHO Nutrition Advisory GroupFocus on salt was based on assessment of evidence of benefit.

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HSFC CIHR Chair in Hypertension Prevention and control

Mandate 2011-2016 to align government and non governmental organizations on a Pan Canadian Hypertension Framework vision and objectives.

– Develop a systematic approach and committee structure for the health care sector to successfully advocate for policy changes to reduce blood pressure in the Canadian population.

– Aligning Canadian public health food policy with global best practices.

Systolic blood pressure greater than 115 mmHg

Figure obtained by cropping a downloaded figure from http://www.healthdata.org July 8 2014,

Burden of hypertension in Canada

• 7.4 million adult Canadians with hypertension • In 2007/8 1100 Canadians a day were diagnosed with hypertension

• > 90% of us are estimated to develop hypertension in a average lifespan

• Antihypertensive drug costs of 3 billion dollars/year• Almost half of all people in Canada over age 60 are taking drugs to control

blood pressure

• 20-25 million physicians visits for hypertension/year• Direct health care costs approximately 10% of overall health costs• Societal burden (including indirect costs) are estimated to be 4.5

to 15% of GDP in high income countries

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Attributable Risk of Lifestyle to Hypertension

Risk factor Approximate attributable

risk for hypertensionIncreased salt in diet 32%

Decreased potassium in diet 17%

Overweight 32%

Sedentary lifestyle 17%

Excess alcohol 3%

Dietary fats ?%

CHMS: Canadian Health Measures SurveyCHMS: Canadian Heart Health Survey

Wilkins et al. Health Reports Feb 2010

The past and current situationfor hypertension in Canada

CHHS 1985-1992

2007 / 2008

Treated and BP controlled

Not Aware

Aware and BP not treated

Treated and BP not controlled

43%

13%

22%

21%

16%

66%

4%

14%

No impact on prevalenceNo impact of lifestyle

Pan Canadian Hypertension Framework

An opportunity to discuss how to improve the prevention and control of hypertension in Canada

2011-2020

Canadian Hypertension Advisory Committee

Committee structure formed to support HSF/CIHR Chair mandate

Comprised of 15 national organizations to advance/operationalize Hypertension Framework

Canadian Hypertension Advisory Committee Membership

Canadian Association of Cardiovascular Prevention and Rehabilitation

Canadian Cardiovascular Society

 Canadian Council of Cardiovascular Nurses

Canadian Diabetes Association

Canadian Medical Association

Canadian Nurses Association

Canadian Pharmacists Association

Canadian Society of Internal Medicine

Canadian Society of Nephrology

Canadian Stroke Network

College of Family Physicians of Canada

Heart and Stroke Foundation of Canada

Hypertension Canada

Public Health Physicians of Canada

Recommendation Priorities

Recommendation

1. Build Healthy Public Policy (1)

2. Re-orient/redesign the health services delivery system

3. Build partnerships to create supportive environments and evolve the healthcare system (2)

4. Strengthen community action (3)

5. Develop personal skills for better self-management

6. Improve decision support (4)

7. Optimize information systems (5)

Provincial Priority, Hypertension Canada, C-CHANGE, Hypertension

experts

CHAMP Initiative

PHAC, Hypertension Canada and new Chair priority

Hypertension Canada/HSF

Priority Areas of Focus

Important & Urgent

Important but less urgent

Reduce the impact of financial interests on

healthy public food policies

Policy Statement on Marketing to Kids

Defining Healthy Food

Sodium Policy & Advocacy

Healthy food procurement

Standardized front of package food labels that

contain health connotations

Healthy Food in Canada

Fiscal Policies (Taxation/Subsidies)

Policy Positions

Highlights of recent national health and scientific organizations actions on dietary sodium

2006: Blood Pressure Canada (BPC), a coalition of 27 organizations and the Canadian Stroke Network prioritize actions to reduce dietary sodium2006-8: BPC strategic planning committee formed 2006-7: BPC policy statement on dietary sodium endorsed by 17 national health and scientific organizations2007: Health and scientific organizations collaborate in Health Canada Sodium Working Group2007: Health and scientific organizations conduct work on the impact of dietary sodium on the health of Canadians 2007-: Extensive education programs for health care professionals and the public- BPC, Hypertension Canada and Canadian Stroke Network2011: Health and scientific organizations write public letter of concern to the Prime Minister and all elected FPT officials regarding the Harper governments lack of support for the Sodium Reduction Strategy for Canada created by SWG2013: Strong national health and scientific organizations support for L Davies parliamentary bill for sodium reduction

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CSPIPHAC/Health CanadaPT’sFood Processing Industry

WHO supports sodium reduction• Internationally, in 2012, the World Health Organization following an

exhaustive and comprehensive review of the clinical interventions and cohort studies of populations

• United Nations (independent national reviews, political and based on advice of the WHO).

• All but 1 comprehensive scientific organization review. • 31 of 31 surveyed national hypertension societies. • Numerous scientific and health NGOs • Global Burden of Disease Study estimated 1.65 million deaths in

2010 from high dietary sodium/year.- 486 authors from 302 institutions in 50 countries, indicated to be the strongest evidence-based assessment of people’s health problems around the world. WHO supported GATES funded.

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• There is no credible national or international health or scientific organization, I am aware of that has stated opposition to sodium reduction to < 2400mg/day and most support <2000mg/day. Canada’s upper limit of <2300 mg sodium/day is broadly supported within the Canadian health and scientific community. Hypertension Canada supports 2000 mg sodium/day

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Who does not support sodium reduction• The Salt Institute.• Some of the food processing industry especially in the

United States.• Several scientists and clinicians who have long

histories of close relationships with the salt or food industries.

• A few dissident scientists most of whom have personally performed research (usually with major methodological weaknesses) that do not support sodium reduction.

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Generating controversyThe studies that have created controversy are based on weak research design

– Unreliable assessment of sodium intake (e.g. spot urine)– Using extreme variation in dietary sodium over a duration of a few

days– Do not address known confounding factors (explanations) for the

outcomes being tested, – Control for blood pressure (the main mechanism of sodium induced

harm), – Conducted in populations with diseases where reverse causality is

likely (i.e. sick people eat less and die more)

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Generating controversy

• Several controversial studies have been conducted by consultants of the Salt Institute (an umbrella organization of the salt industry)

• The results of the weak studies have been highly leveraged into public attention by the food and salt industries

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Sodium science

1) The use of weak methods indicate the need for research standards to be set.

2) There is a need for a high quality RCT.3) To me the enthusiastic claims to media that

sodium is not important for health based on frail methods is endangering programs designed to save millions of lives/year.

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Science of Salt Weekly• Science of Salt Weekly is an initiative of the

(CIHR/HSFC) Chair in Hypertension Prevention and Control.

• Funding for this 2-year initiative has been provided by the Canadian Stroke Network and the George Institute for Global Health.

• This weekly newsletter features short summaries of relevant Medline-retrieved articles related to dietary sodium.

• To download issues or to sign-up for automated email updates, visit: http://www.hypertensiontalk.com

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Setting Research standards

• An international coalition of organizations lead by the World Hypertension League is forming to set research standards and maintain regular systematic reviews of the literature

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Some Best Global Practices to achieve the WHO target (<5 g salt/day) and United Nations target

(30% decrease in dietary salt by 2025).•Regulatory approaches that set targets and timelines on sodium content of processed foods (South Africa and Argentina)•Voluntary approaches that set targets and timelines on sodium content of processed foods with close government oversight and monitoring (Finland, England, Ireland, Brazil, Chile (expected soon to be regulatory)

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Changes in DBP, salt intake and stroke deaths in Finland

5600 mg

3360 mg

DBP Salt Stroke

Karppanen H et al Progress, Cardiovascular Disease 2006;49:59-75

Changes in CVD, blood pressure and salt consumption in the England 2003-2011

Japan not well evaluated but reduced salt intake, reduced population BP and reduced stroke

Sodium science:

• A substantive but incomplete evidence base indicates the widespread addition of large amounts of sodium to food is one of the largest public health disasters of industrialization killing 1.65 million/yr. in 2010

• Current controversy is largely fueled by weak research methods, and financial interests.

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