History

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)

Sodium

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):

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

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 .

Herbs

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.