High blood pressure has become a common occurrence amongst the population and diet plays a major role in its development. Let’s discuss the role of potassium and find out if potassium lowers blood pressure.November 16, 2022 6:03 pm March 18, 2022 5:40 pm
What is potassium?
Potassium is an essential nutrient that is naturally abundant in many foods and supplements. Moreover, potassium is found in all of our bodily tissues and is crucial for normal cell function. In fact, along with sodium, it plays an important role in maintaining and regulating extracellular fluid volume (i.e. the fluid outside of cells) and plasma volume.
Our kidneys control potassium excretion in our bodies in response to dietary intake of this nutrient. In fact, in healthy people, potassium excretion occurs rapidly through urine after having consumed potassium. However, one exception is if body stores are depleted, in which case the body holds on to potassium to make use of it.
In healthy individuals with normal kidney function, abnormally low or high levels of potassium are very rare. However, conditions such as diarrhoea, kidney disease and vomiting can alter the potassium balance in our body and lead to either hypokalemia (low potassium) or hyperkalemia (high potassium).
Sources of potassium
Potassium is abundant in many different foods and beverages. Fruits and vegetables are some of the best sources of potassium, and some legumes such as soybeans are also great sources. Dried apricots, lentils and prunes are some of the richest plant sources of potassium. Furthermore, whole wheat varieties of breads and cereals contain higher potassium levels compared to their refined counterparts. Amongst animal sources, meat, fish, dairy products and poultry also contain potassium.
In most western eating patterns, the top contributors of potassium in the diet are potatoes, milk, tea and coffee. Unlike for some other nutrients, our body absorbs most of the potassium we ingest. In fact, our body absorbs up to 90% of the potassium we consume through foods and beverages.
Nowadays, many multivitamins and supplements contain potassium. However, most supplements only provide small amounts of potassium (about 99mg) per serving. Considering that the recommended daily allowance (RDA) for adults is 3500mg, potassium supplements do not significantly contribute much to the diet.
How do I know if I’m getting enough potassium?
The WHO has recorded that the world’s population overall consumes too much sodium and not enough potassium. In fact, a study conducted cross-nationally observed the intakes of sodium and potassium of four populations and compared them to recommended intakes for both nutrients. The results were astounding and it was found that the percentage of the population meeting their target sodium-potassium goals was 0.3%, 0.15%, 0.5% and 0.1% respectively in the USA, Mexico, France and UK. In fact, this is a global public health concern because of the health consequences associated with insufficient potassium intake and high sodium, namely cardiovascular disease.(1)
Not only is an inadequate diet the cause for low potassium intake, some population subgroups are more likely than others to struggle with adequate potassium consumption. For example, people with inflammatory bowel disease such as Crohn’s disease have impaired intestinal absorption and may not absorb potassium adequately. Moreover, certain medications such as laxatives or diuretics can dramatically alter our body’s potassium levels. In addition, heavy sweating, vomiting, diarrhoea and dialysis can all contribute to low potassium levels, ultimately leading to hypokalemia. Some symptoms of hypokalemia include constipation, fatigue, muscle weakness and general malaise.
Overall, ensuring that you eat a varied diet full of fruit, vegetables and whole grains is one of the top ways to ensure that you are meeting your potassium requirements. There is no need for supplementation in healthy individuals unless you have been recommended to do so by your doctor for a specific medical condition.
What about high blood pressure?
It is a well known fact that high blood pressure is a major risk factor for coronary heart disease and stroke. Sadly this is a growing concern amongst the population and it has become a common occurrence in many individuals. There are many factors that can lead to high blood pressure including a diet high in salt, excess alcohol consumption, stress, a lack of physical activity and being overweight or obese.
However, a sometimes overlooked cause of high blood pressure is a low potassium intake in the diet. This is especially the case if low potassium is accompanied by excess salt consumption. In fact, as previously mentioned, potassium and salt are tightly regulated in the body and when one of the two is out of balance, it directly impacts the other.