Sodium, Salt, High Blood Pressure

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Why does a blood pressure above the norm matter?

Blood pressure is simply the force of the blood against the blood vessels walls as they carry blood from the heart to the rest of the body. When the force against the wall is higher than normal, we call it high blood pressure or hypertension.

The higher pressure can cause damage to the wall resulting in the wall becoming more rigid and making the heart work harder to push the blood around the body. This higher pressure and damage is what can lead to heart attacks and strokes.   So what does diet have to do with all this and how can the pressure be reduced?

A little background on sodium and potassium.

It is difficult to discuss sodium without also considering potassium as the two work as a team in the body. Prior to the introduction of convenience foods around the 1950s the human body had adapted to a world where our food provided very little sodium and an abundance of potassium.

THEN: Potassium everywhere, but where is the sodium?

Potassium is widely available in nature and is present in most unprocessed foods such as fruits, vegetables, grains, nuts, beans, the foods that made up most of our diet over the centuries. We never had to worry about getting enough potassium or taking excess sodium.

Potassium and sodium are important minerals for maintaining the water balance of our body and the kidney is the key player in maintaining this balance.

Our kidneys, adapted to the potassium rich, sodium poor environment.  The kidney developed ways to hold onto sodium, as a precious rare mineral and to get rid of potassium in urine, because it was so available.

NOW: Sodium everywhere, but where is the potassium?

If we fast-forward to today, sodium is everywhere, not just as table salt but added to processed foods as flavour enhancers such as monosodium glutamate, acidity regulators such as sodium benzoate in soft drinks, as preservatives such as sodium nitrate in processed meats.

Our intake of sodium has increased markedly while our potassium intake has dwindled. However, our kidneys are still holding onto sodium and getting rid of the potassium as they always did, they have not adapted to this reversal in availability of the two minerals.

Why does the extra sodium matter?

Sodium draws water to itself, which means that the sodium in the blood holds onto fluid and the kidney has a lot of trouble getting rid of the extra fluid. This increases the amount of fluid present in the blood and so the blood pressure is increased.

The DASH way of eating

The DASH diet (Dietary Approaches to Stop Hypertension) has proven to be successful for reducing blood pressure. In fact, just two weeks on the DASH diet leads to a reduction in blood pressure.

The approach recommends eating foods lower in sodium, but also emphasizes foods that are rich in potassium. It goes further, packing a bigger punch because the recommended foods are also rich in calcium, magnesium and high in fibre.

Research supports the DASH diet showing that reducing high blood pressure is about more than just sodium, it involves potassium, calcium, magnesium, and fibre too. Essentially any diet that emphasizes eating lots of vegetables, fruits and wholegrains while de-emphasizing processed foods will be beneficial for overall health beyond just blood pressure.

Indeed, the DASH diet has been shown to reduce weight, reduce unhealthy cholesterol as well as reducing blood pressure.

While there is currently a changing landscape on the question of what are considered healthy fats in the diet, the DASH diet advises consumers of meat and dairy to choose fish, poultry and low fat dairy products. Given the proven benefits of the overall dietary approach, this advice remains valid.

So what is the DASH diet?

  • Reduce sodium intake to ideally 1500mg daily but less than 2300mg
  • Increase vegetable and fruit intake
  • Choose a variety of whole grain cereals: eg. barley, oats, quinoa, buckwheat. More information on whole grains here.
  • Choose protein from a range of sources including beans, lentils, nuts, seeds, lean meats, skinless poultry and fish
  • Choose low fat dairy or plant beverages

Overall this approach improves a person’s intake of magnesium, calcium, potassium, fibre, lowers saturated fat and sodium.

When eating this way most of the time, there is little concern over eating out occasionally or indulging during celebrations such as family holiday dinners.

Some Tips & Tricks

Reduce sodium to between 1500mg and 2300mg – 1 tsp (5g) of table salt has 2300mg of sodium.

  • The biggest impact on sodium intake can be avoiding processed foods on a regular basis as 77% of sodium in the diet is from processed foods. The less salt you eat, the more your taste buds will adjust and remarkably quickly.
  • Avoid processed meats, deli meats, condiments like mustard, relishes
  • One client had a great idea – he bought a box of salt packets from Staples to control his salt intake. Each salt packet was half a gram so about 200mg of sodium.  That way he could monitor his daily intake and still enjoy some salt.
  • Experimenting with adding herbs and spices to meals to switch up the flavours can be interesting. If you are feeling less adventurous, The Mrs Dash products are a great short cut.
  • Be cautious with salt alternatives and have a conversation with a health professional first as the salt alternatives often contain potassium and may not be compatible with some medications.

Consume more potassium:

  • Good sources include all fruits, vegetables, and beans, fish and natural yogurt. Especially leafy greens, dandelion greens, avocados, tomatoes, watermelon, winter squash, white beans, potatoes, sweet potatoes, dried fruits, wild caught salmon.
  • Potassium is easily lost from foods if they are cooked in water and the water drained away. Try alternative cooking methods such as baking, sautéing, steaming, soups and stews that retain the fluid as part of the meal.
  • Again, if you are on medication or have kidney disease, have a conversation with a health professional before significantly increasing your potassium intake or green leafy vegetable intake.

If you would like to know more about how to introduce some of these changes daily and which may be more relevant to your situation, schedule an appointment to discuss strategies for moving forward.

All content provided on this website is for general information purposes only and is not intended to replace medical or specialist advice.

A qualified Medical Herbalist is always your best resource for information related to herbal medicines.

Registered Dietitians are a reliable and trusted resource for nutrition related information, always up to date and always ready to work with you to realise your goals.