Nutrition and Hypertension

Last Authored:  Dec 2014, Anne Fougere
Last Reviewed: Dec 2014, Christy Charles



main articles: blood pressure   hypertension   blood pressure readings


Blood pressure is the pressure applied to the artery walls when blood is pumped by the heart.  High blood pressure, clinically referred to as hypertension, is diagnosed when blood pressure readings are over 140 systolic or 90 diastolic on at least three occasions. High blood pressure is a worldwide problem. According to the World Health Organization (WHO) the number of adults aged 25 years or older diagnosed with high blood pressure increased to 1 billion in 2008 from 600 million in 1980 (World Health Organization, 2013). Approximately 40% of the world’s population over age 25 years has been diagnosed with high blood pressure (World Health Organization, 2013).


Table salt, courtsey of Garitzko

There are two types of high blood pressure, essential or primary hypertension, and secondary hypertension. 90-95% percent of cases are essential or primary hypertension, which is often caused by lifestyle factors; however, genetics also play a role. (Mahan, Escott-Stump, & Raymond, 2012). Secondary hypertension occurs as a result of another disease affecting the body, usually endocrine.


High blood pressure is often referred to as the “silent killer” because it can remain asymptomatic for years. Untreated and/or uncontrolled hypertension can lead to health conditions such as stroke, coronary artery disease, and kidney failure (Dietitians of Canada, 2014b).


There are both behavioural and metabolic risk factors that can lead to essential hypertension. Behavioural risk factors include an unhealthy diet, tobacco use, physical inactivity, excess alcohol intake, and poor stress management. Metabolic risk factors include overweight and obesity, diabetes, and high cholesterol (World Health Organization, 2013). Other non-modifiable risk factors include older age and family history of hypertension.  Lifestyle modification is key to the management of high blood pressure (Dietitians of Canada, 2014b). Social determinants and drivers that contribute to high blood pressure include globalization, urbanization, ageing, income, education, and housing (World Health Organization, 2013).

The primary focus of this article will be the dietary management of essential hypertension. This paper will also address lifestyle modifications that can help to lower high blood pressure, as well as how to conduct a thorough nutritional assessment for individuals with high blood pressure.

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Nutrition Assessment  

A thorough assessment of food intake, physical activity, and other lifestyle factors are needed to determine what is contributing to the patient’s high blood pressure.

  • History
  • Physical Exam
  • Lab Investigations



Health History

Assess for co-morbidities (e.g. diabetes, dyslipidemia) as each requires unique nutrition therapy that will augment the diet therapy for high blood pressure.

Document all medications the patient is currently taking, specifically assess for hypertension treatments that will affect sodium or potassium levels.

Ask patient about personal and family medical history, particularly related to cardiovascular and endocrine/metabolism diseases.

Assess patient for the risk factors discussed above.

Diet History
To assess the usual energy and nutrient intake of the patient, conduct a Diet History. Particular attention should be paid to sodium and potassium intake. In addition, take note of pre-prepared or processed foods, high fat and high sugar foods, magnesium, vitamin D and calcium intake.

A nutrient software analysis program is ideal to assess actual intake of key nutrients; however this is costly and time consuming; a detailed multi-day food record can suffice.


Environmental Factors
It is wise to assess the patient’s ability to afford food, supplements and medications to inquire how they access food (purchase at markets/stores, family garden, etc.). This will allow for nutrition recommendations that can be implemented by the patient.

Assess if the patient has much control over what foods enter the house and how they are prepared (e.g. who does the procuring and preparation of meals).

Physical Exam

Aspects of the physical exam include:

  • Collect the patient’s height and weight to calculate BMI
  • Measure waist circumference
  • Measure waist to hip ratio
  • Monitor vitals, especially blood pressure
  • Monitor body weight

Laboratory Investigations

If available, review the following pertinent lab values to assess for co-morbidites such as dyslipidemia, diabetes, signs of kidney disease, etc.

  • Lipid profile
  • Blood Glucose
  • Sodium and Potassium levels
  • Creatinine (GFR)

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Nutrition Management of Hypertension

Lifestyle modifications are the best management strategy to control blood pressure (National Heart, Lung, and Blood Institute, 2003).  Nutrition counselling for the hypertensive patient should address the key nutrients sodium, potassium, calcium, and magnesium, the “DASH Diet”, achieving optimal body weight, alcohol intake, and if appropriate, herbs that can affect blood pressure.


Patients should be encouraged to get 30 minutes of low to moderate physical activity each day as this will decrease systolic blood pressure by 1-9 mmHg (Escott-Stump, 2012).  Examples of low to moderate activities include brisk walking, gardening, and bicycling.

People with high blood pressure may also have diabetes, kidney disease, and cardiovascular disease and as such prescribed diets will need to flex to meet demands of multiple health conditions.

  • sodium
  • potassium, calcium, magnesium
  • DASH diet
  • optimal body weight
  • alcohol
  • herbs


One of the most important dietary factors to consider in decreasing blood pressure is sodium intake (World Health Organization, 2013).  Excess intake of sodium can increase blood pressure. If sodium intake is limited to no more than 2300mg of sodium per day, this can lower systolic blood pressure by 2-8 mmHg (Escott-Stump, 2012).

The Dietary Reference Intakes (DRIs) set the Adequate Intake (AI) for sodium at 1500mg (Health Canada, 2010) this is equal to the amount of sodium that you would find in 2/3 teaspoon of table salt.  All patients with hypertension should aim for sodium intake less than or equal to the AI.

Counsel patients to flavour foods with herbs and spices instead of salt and to limit consumption of foods that are high in sodium, such as processed meats, some canned foods (e.g. canned soups), cheeses, breads, sauces, pickled foods, and condiments.

Beware of potassium chloride salt substitutes if client has disease conditions that reduce urine output, such as kidney disease or if they are on potassium sparing medications such as ACE inhibitors or potassium sparing diuretics which decrease excretion of potassium through urine, these increase risk of hyperkalemia (Mahan, Escott-Stump, & Raymond, 2012).

Potassium, Calcium and Magnesium

Potassium, calcium, and magnesium are important minerals that work together to help lower blood pressure. If dietary intake or serum levels of these minerals are low, intake should be increased through diet, and supplementation if necessary.

Food sources of potassium include bananas, oranges, tomatoes, potatoes, lentils, beans, milk, nuts, and fish.  Individuals who are on potassium sparing medications such as ACE inhibitors or potassium sparing diuretics need to monitor their potassium levels and limit intake from diet as too much potassium can increase the risk of hyperkalemia (Mahan, Escott-Stump, & Raymond, 2012).

Food sources of calcium include cow’s milk, yogurt, beans, leafy green vegetables, canned fish with bones (such as salmon), and tofu.

Food sources of magnesium include nuts, seeds, spinach, fish, beans, soy, lentils, and whole grain cereals.

Dietary Approaches to Stop Hypertension Eating Plan (DASH Diet)

The DASH diet has been shown to lower blood pressure by 8-14 mmHg (Escott-Stump, 2012). The DASH diet is rich in fruit, vegetables, low-fat dairy foods, and is low in saturated and total fat. It places a greater emphasis on whole grains, consuming more fish, poultry, beans, nuts, eating less sodium and choosing foods that are high in calcium, magnesium and potassium (Dietitians of Canada, 2014a). When followed, patients can experience a decrease in blood pressure readings in as little as two weeks (Escott-Stump, 2012).

The DASH diet is not suitable for those with renal disease as it contains high levels of potassium, phosphorous, and protein (Escott-Stump, 2012).

The Dash Eating Plan is as follows and is based on a 2000 calories diet (Dietitians of Canada, 2014b):


Daily Servings

What is one serving?


4 - 5

½ cup fresh, frozen or canned fruit
6oz fruit juice
¼ cup dried fruit
1 medium fruit



½ cup cooked vegetables
1 cup of raw leafy vegetables
6oz vegetable juice

Grains (mostly whole grains)


1 slice of bread
½ cup cooked rice, pasta or cereal

Low Fat Dairy products


1 ½ oz cheese
1 cup of milk
1 cup of yogurt

Lean meat, poultry, fish

2 or less

3 oz

Nuts, seed and legumes

4-5 per week

⅓ cup of nuts
1 tbsp of seeds
½ cup of cooked legumes

Unsaturated fats and oils


1 tsp of margarine
1 tsp vegetable oil

Sweets and added sugars

Limit of 5 per week

1 tbsp of sugar
1 tbsp of jam/jelly

Achieving/Maintaining Optimal Body Weight

If an optimal body weight (BMI 18.5-24.9) is achieved and maintained, this can lower blood pressure; in addition, for every 10kg lost, systolic blood pressure will decrease by 5-20 mmHg (Escott-Stump, 2012).  The DASH diet will help address poor eating habits; also please see Nutrition Management for Obesity.


Alcohol intake should be limited as consuming large amounts can result in increased blood pressure, and alcohol contributes “empty calories” in that it provides calories with little nutrients and can contribute to weight gain.  In Canada, the Low Risk Drinking Guidelines recommend alcohol consumption be no more than 15 drinks per week for men and no more than 3 drinks a day most days; for women consumption should be no more than 10 drinks per week and no more than 2 drinks a day most days (Canadian Centre on Substance Abuse, 2013).


One drink is equal to 1.5 oz of liquor, 5 oz of wine or 12 oz of beer .


Some herbs can directly affect blood pressure or affect medication taken for blood pressure. Herbal remedies that can negatively affect blood pressure include black licorice, ephedra, ginseng, and plantain (Dietitians of Canada, 2014b). Patients with high blood pressure should be advised against taking these herbs or products that contain these herbs.

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References and Resources


Additional Resources
Heart and Stroke Foundation
U.S. National Library of Medicine
Centre of Disease Control and Prevention
WHO Global Brief on Hypetension

Canadian Centre on Substance Abuse.  (2013). Canada’s Low-Risk Drinking Guidelines. Canadian Centre on Substance Abuse. Retrieved December 3 2014, from

Dietitians of Canada. (2014a). A DASH of healthy eating can help control blood pressure. Retrieved November 26, 2014, from EatRight Ontario:

Dietitians of Canada. (2014b). Cardiovascular Disease - Hypertension: Treatment Toolkit. Practice-Based Evidence in Nutrition.

Escott-Stump, S. (2012). Nutrition and Diagnosis-Related Care (7th ed.). Baltimore, MD: Lippincott Williams & Wilkins.

Health Canada. (2010). Dietary Reference Intake Tables. Retrieved November 26, 2014, from

Mahan, L. K., Escott-Stump, S., & Raymond, J. (2012). Krause's Food and the Nutrition Care Process (13th ed.). St. Louis, Missouri, United States of America: Elsevier.

National Heart, Lung, and Blood Institute. (2003). Your Guide to Lowering Blood Pressure. Retrieved November 21, 2014, from National Institutes of Health:

World Health Organization. (2013). A global brief on hypertension: silent killer, global public health crisis. WHO. Retrieved November 21, 2014, from

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