If you have hypertension, you’re probably careful about how much sodium you consume. That’s wise, since reducing sodium intake to 2,000 milligrams a day can help lower blood pressure.
But it’s important to consider your overall diet, too. The foods you eat on a regular basis can have an important blood-pressure-lowering effect.
According to new research from Thailand, you’ll find those foods in three different dietary patterns: the DASH diet (DASH stands for Dietary Approaches to Stop Hypertension), the Nordic diet and the portfolio diet. Each was found to significantly lower blood pressure.
Hypertension, a leading preventable risk factor for heart disease, heart attack and stroke, affects almost one in four Canadians. Blood pressure consistently at or above 140/90 mmHg (millimetres of mercury) indicates hypertension, but if you have diabetes, 130/80 mmHg is considered high.
About the study
The latest research, published in the American Journal of Clinical Nutrition, compiled and analyzed existing evidence from 50 reviews of randomized controlled trials that investigated the effectiveness of dietary patterns on lowering blood pressure.
A dietary pattern is defined as the overall combination of foods eaten on a regular basis, which together produce synergistic health effects. Researchers study dietary patterns to capture the complexity of diet.
The analysis included 12 dietary patterns, including DASH, Mediterranean, Nordic, vegetarian, low-fat, low-carbohydrate, high-protein, low-sodium, low glycemic index, portfolio, pulse and Paleolithic diets.
Among these, the DASH diet, recommended by many health organizations, was associated with the greatest reduction in blood pressure. Adhering to the Nordic diet, portfolio diet and low-salt diet also significantly lowered blood pressure.
Evidence for the blood-pressure-lowering effect of other dietary patterns was inconsistent.
Similar foods, synergistic effects
The ability of the DASH, Nordic and portfolio diets to lower blood pressure is attributed to shared foods found in these eating patterns.
All three diets are plentiful in fruits, vegetables, whole grains, pulses (e.g., beans and lentils), seeds and nuts and low in processed meats, sweets and saturated fat. The DASH and Nordic diets also both emphasize dairy products.
It’s the interaction of key nutrients and antioxidants in these foods, including calcium, magnesium, potassium, vitamins, fibre, omega-3 fats and polyphenols, that’s thought to provide a powerful antihypertensive effect.
Dietary patterns to lower blood pressure
If you have hypertension, eating the right diet can help lower your blood pressure. Doing so can also prevent high blood pressure in the first place.
Here’s a quick guide to the DASH, Nordic and portfolio diets. Remember, regular exercise, weight control, limiting alcohol and reducing sodium are also key strategies to prevent and lower high blood pressure.
Hallmark foods of the DASH diet include vegetables, fruit and low-fat dairy products, which are consumed daily. The recommended number of servings will depend on your calorie intake.
A serving of nuts, seeds and/or pulses should be eaten four times a week. (One serving is equivalent to one-half cup of pulses, one-third cup of nuts, two tablespoons of nut butter or two tablespoons of seeds.)
Choose 100-per-cent whole grain foods instead of refined grain products. Limit intake of added fats and sweets.
This eating pattern, traditional to people living in Denmark, Finland, Iceland, Norway and Sweden, also features vegetables, fruit, whole grains and low-fat dairy (Icelandic yogurt, kefir).
Root vegetables such as potatoes, carrots, beets and turnips are predominant, as are broccoli, cabbage and Brussels sprouts. Common fruits include berries, apples, pears and plums.
Steel-cut oats, whole-grain rye bread and barley are whole grain staples. Oily fish and leaner white fish are eaten regularly. Canola is the principal cooking oil.
This plant-based eating plan, developed by Dr. David Jenkins from the University of Toronto, combines four recognized cholesterol-lowering foods: nuts, soy protein (e.g., tofu, edamame, soy milk, soy burgers), viscous fibre and plant sterols, all of which are eaten daily.
Foods rich in viscous fibre include oatmeal, whole-grain rye and pumpernickel bread, barley, psyllium-enriched breakfast cereal, pulses, eggplant and okra. Foods fortified with plant sterols, such as juice, spreads and yogurt, are included in the diet.
Leslie Beck, a Toronto-based private practice dietitian, is Director of Food and Nutrition at Medcan.
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