Many people easily overlook micronutrients – this includes minerals and vitamins. They focus on the macronutrients – how much carbs, fats and protein they eat along with their sources of these macronutrients. This is important, but so are the micronutrients – and one micronutrient which is essential for daily function and has the potential to enhance running performance is potassium!
What is Potassium?
Potassium is a mineral and electrolyte essential for cell, tissue and organ function. It is, in fact, the third most abundant mineral in the body and is easily forgotten and neglected. Potassium interacts directly with sodium and can be used to help reduce blood pressure. It is regulated directly by the kidneys and aids muscular contraction, prevents muscle aches and supports digestive health.
The world health organisation recommends consuming 3,510mg potassium – unfortunately, these recommendations are met by a very small percentage of the population. The food and nutrition board suggests an even higher intake of potassium at 4,700mg potassium for adults. Increased potassium intake has been shown to reduce both systolic and diastolic blood pressure in adults which is beneficial as many people consume too much sodium as this is the salt typically used in many processed foods, so by intaking potassium, we can help counteract the effects of a high sodium diet. It can help to reduce hypertension which is a major risk factor for cardiovascular diseases, particularly coronary heart disease and stroke.
Because potassium is such an essential mineral, consuming low amounts of potassium poses some health risks which are explained later down below.
Why do we need Potassium?
Potassium Regulates Fluid Balance
Our body is made up of around 60% water. Potassium helps to regulate fluid balance within the cells (intracellular fluid) and works with sodium which influences the amount of water outside the cells (extracellular fluid). Both potassium and sodium are electrolytes (minerals that dissolve in water). When there is an unequal balance of electrolytes, water shifts to the side with more electrolytes to regulate the electrolyte concentration.
As many people consume far more sodium than potassium, consuming more potassium can help to keep your fluid balance in check and ensure your cells have enough water as a high sodium diet will cause them to become undersaturated which can leave you feeling dehydrated and thirsty. This dehydration can lead to negative effects on the heart and kidneys. A potassium-rich diet combined with hydration can help to keep your cells functioning efficiently.
Interestingly, if you have high blood pressure due to the consumption of lots of sodium, the increased consumption of potassium can actually offset this and help to decrease blood pressure.
Potassium Aids the Nervous System
The movement of potassium ions is used in changing the voltage of a cell in order to activate a nerve impulse. The same can also be said for the mineral sodium. Using these impulses, our nervous system relays messages between the body and brain.
Potassium ions generate nerve impulses when they move out of cells and sodium ions generate nerve impulses when they move into cells. If potassium levels are too low, then the body’s ability to create nerve impulses will likely be negatively affected.
Potassium Regulates Muscular Contractions
We know now that potassium helps to generate the nerve impulses used by our nervous system in relaying messages between the body, and the same is true for muscular contractions. The nervous system helps to regulate muscular contractions and low levels of potassium can affect the signals generated, reducing the force produced by our muscles.
It also helps to ensure regular heartbeats within the heart, as the heart is also a muscle. Low levels of potassium can alter the heartbeat and cause arrhythmias, and too high levels can cause the heart to become dilated and flaccid, producing an abnormal heartbeat and weaker muscular contractions.
What are the Risks of Low Potassium?
Potassium deficiency is also known as hypokalaemia. Risks (depending on how potassium deficient you are) include:
- Swelling of glands and tissues
- Muscle weakness
- Glucose intolerance
- Problems with blood pressure
- Cardiac arrhythmia (in more extreme cases)
Who is at Risk for Low Potassium Levels?
Well, if you happen to suffer from any of the symptoms listed above then there is a chance you could not be consuming enough potassium. People who are at increased risk for low potassium levels include:
- Those who eat small amounts of vegetables.
- Athletes or those exercising at a high intensity or for a long duration as potassium is lost through sweat.
- Those who take diuretics as there is an increased loss of fluid and mineral ions such as potassium from the body.
- People with uncontrollable diabetes.
- People on a low calorie diet (who are possibly at risk of other mineral deficiencies as well).
Benefits of Potassium
- Reduced Blood Pressure: Various studies have shown how potassium can help to reduce blood pressure and alleviate hypertension by increasing intake of potassium. Potassium intake has been associated with lower systolic and diastolic blood pressures.
- Decreased Risk of Cramps: Mineral deficiencies have been associated with muscle cramps. By increasing potassium intake, there is a lower risk of muscle cramps and increased muscular strength. Cramps are more likely if the person is also dehydrated.
- Osteoporosis Prevention: A direct correlation has been found between increased intake of dietary potassium and increased bone density which can help reduce the risk of osteoporosis (thinning of the bones). This is a condition where your bones are weaker and are more vulnerable to fractures and injuries. Potassium salts help the bones not to reabsorb acid and to maintain vital mineral content which assists in improving bone health.
- Reduced Stroke Risk: High blood pressure can increase the risk of strokes due to the formation of blood clots in the arteries flowing to the brain. Potassium helps to lower blood pressure which can help to reduce the risk of stroke. An analysis of 33 trials, (22 randomised controlled trials and 11 cohort studies) involving 128,664 participants found that people who consumed the most potassium had a 24% lower risk of stroke than those who ate the least.
Sources of Potassium
Whilst it is possible to obtain potassium in supplement form, the best way to consume potassium is through whole foods and plenty of vegetables. This is because it is hard to find supplements which contain large enough doses of potassium to ensure you meet the recommended daily values and some studies tend to find that reduced risk of various issues is caused by an increase in potassium consumed from dietary sources rather than supplements.
Just to recap, the recommended daily values of potassium are 3,510mg – 4,700mg.
Top Dietary Sources of Potassium
- 100g lima beans – 1724mg
- 100g black beans – 1483mg
- 100g red kidney beans – 1359mg
- 100g dried apricots – 1162mg
- 100g broad beans – 1062mg
- 100g pistachios – 1025mg
- 1 whole avocado (approx 200g) – 975mg
- 100g almonds – 705mg
- 100g cashews – 660mg
- 100g brazil nuts – 659mg
- 100g spinach – 558mg
- 1 medium banana (aprrox 7.5″ long, 122g) – 422mg
- 100g sardines – 397mg
- 100g acorn squash – 347mg
- 100g sweet potato – 337mg
- 100g broccoli – 316mg
As you can see there are plenty of sources of potassium available for you to consume. Whilst there are many more dietary sources of potassium, I have mentioned some of the highest although the best tip I could provide would be to include a range of foods within your diet. Please note that the mg of potassium will vary from source to source and depend on the environment the produce has been brought up in. Also, whilst nuts are a rich source of potassium, I would not recommend consuming 100g of them daily due to their high calorific value unless you have a expend a high level of energy daily from exercise.
Were you aware of the importance of potassium? Will you be making any conscious changes to your diet? Let me know down below!