High blood pressure, also known as hypertension affects approximately six million Canadians. Nine in ten people will develop high blood pressure in their lifetime; and about 17% are unaware that they have the condition. Over time, hypertension can cause hardening and thickening of the arteries (atherosclerosis), which can lead to heart attack, stroke, or other complications.
While many aspects cannot be controlled, such as our genetics, age, gender, and race – many lifestyle factors can. This includes physical activity, stress, smoking, alcohol consumption, sleep, and of course my favourite topic – Food and nutrition.
The first section of this blog explores the well-known relationship between sodium and hypertension, while the second half explores other important nutrients and dietary strategies associated with lowering blood pressure.
Sodium and blood pressure
Sodium has many critical roles in the body, including: the maintenance of normal fluid and electrolyte balance, assisting in nerve impulse transmission, and muscle contraction
Sodium is also a principal constituent of salt (Chemical symbol is NaCl – one sodium and one chloride), and is the mineral we often hear about in relation to blood pressure.
For instance, excesses in dietary sodium can increase blood pressure in individuals with high blood pressure and those older than 40 years of age. In fact, approximately 50% of the population with high blood pressure is “salt sensitive”, in contrast to 25% of those with normal blood pressure.
Furthermore, one in three people with high blood pressure would have clinically defined normal blood pressure if they consumed less sodium in their diets.
Lowering sodium in diet is a hallmark of the DASH dietary strategy. DASH stands for Dietary Approaches at Stopping Hypertension, and is recommended by the Canadian Heart and Stroke Foundation for managing high blood pressure. More on this later.
Where do we find excess sodium in our diet?
Nearly everywhere! All foods naturally contain sodium; however, this is rarely in excess of the body’s needs. It is the added sodium we find in condiments, pickled foods, processed foods, at restaurants and at the table is where intake is too high, broadly speaking as a society.
As much as 75% of the sodium in people’s foods come from Manufacturers; about 15% comes from salt added during cooking and at the table; and only 10% comes from the naturally occurring amount in foods.
In fact, the high prevalence of salt in our food supply has made sodium the only nutrient where public health officials recommend keeping sodium below the tolerable upper intake (UL) as opposed to the adequate intake (AI), simply because of the impractical logistics of Canadians limiting sodium in their diet in the context of our current food supply systems.
For reference, the AI for sodium is 1500mg for adults 19-50 years old. The UL is 2300mg, equivalent to a teaspoon of salt per day total. The average sodium intake for Canadians is 3400mg.
More on DASH eating strategy
DASH is based on two studies that looked at reducing blood pressure through diet. Within this pattern, which is characterized by plenty of vegetables and fruit, and low fat dairy, and lower in saturated fat, saw blood pressure lowered within two weeks. In the study, all groups lowered sodium below 3,300mg. However, the best results on blood pressure were found in those with the lowest sodium intake.
Another hallmark of the DASH relates to higher potassium intake through whole foods like vegetables and fruits. Potassium has a counterbalancing role to sodium with respect to physiologic control of blood pressure. DASH also includes foods rich in magnesium, like nuts and seeds, which helps you reabsorb potassium in the kidneys. The interplay of nutrients in physiologically control of homeostasis is complex to say the least, but know that the variety and emphasis on whole foods contributes positively to health in ways that go beyond just lowering salt.
While some aspects of the DASH dietary pattern found on the Heart and Stroke Foundationwebsite seem prescriptive (Ex. So and so number of servings of so and so food group), I recommend to look at it is not as a diet, but a dietary approach. Or rather, a guide.
Similar to the Mediterranean dietary pattern, DASH focuses on whole foods, is very plant-forward, fibre rich, and emphasizes variety in diet. In fact, both are considered by experts as the top two approaches for chronic disease prevention.
Overall, DASH and Mediterranean dietary approaches are very similar, very flexible, and are both considered excellent models for dietary approaches to lowering blood pressure and supporting heart health. However DASH is a more suitable model for managing blood pressure specifically.
Healthy eating tips to help lower blood pressure – summary
- Follow a DASH dietary pattern
- Choose a wide variety of whole foods
- (Ex. Vegetables, fruits, legumes, whole grains, nuts, seeds)
- Be plant-forward in your dietary pattern
- Do not add salt at the table
- Minimize processed foods, condiments, pickled products, and fast food
- Choose lower sodium products by using the nutrition facts table to compare products
- Try some of the many salt replacements like Mrs. Dash, which comes in many varieties
- Make your own condiments, sauces, and marinades focusing on herbs, spices, and aromatics (Ex. ginger, garlic, onion). See recipe below!
- Follow complementary lifestyle modifications and guidelines such as getting adequate sleep, regular physical activity, and incorporating stress reduction practices
Recipe: Trinidad green spice
I always say I learn as much from my clients as they do from me. And my first client was from Trinidad. From her, I learned about green spice, a staple condiment in many Trini households. I also discovered that it can be a flavour-packed low-sodium ingredient that is very versatile. You can add it to meat marinades, soups, salad dressings, eggs, and more!
An example recipe can be found below, but the recipe can be tweaked in many ways with various herbs and spices. That said, the dominant herb should be cilantro, a replacement for an ingredient called Shadow Beni – the hallmark herb in authentic Trini green spice.
Ingredients:
- 1 medium Lemon Juiced
- 2 bunches (2-3 loosely packed cups) cilantro
- 3-4 stalks celery
- 6-8 cloves garlic
- 1 large shallot (or a small red onion)
- 1-2 thumb sized pieces of ginger
- 1Tbsp Thyme (fresh or dried)
- Add additional herbs as desired
Directions:
Add all ingredients to a food processor. Pulse until ingredients are combined. Mixture should be thick. However, you can also process into a puree depending on your intended uses.
Tip: Dilute the mixture with oils, vinegars, or water for marinades, salad dressings, spreads and more!
Working together
Working with the Preventous dietitian is a good start to finding tailored nutrition strategies to lower your blood pressure. We can also set you up with our nutrient tracking app, Keenoa, to look at your daily intake of key minerals like sodium and potassium. Together let’s create and implement strategies to optimize your blood pressure through nutrition. Book an appointment or contact me here.
Dan Neuman
Registered Dietitian