Cardiac risks and potassium deficiency

Potassium is a crucial mineral for muscle function, especially heart muscle function. Along with water, potassium is involved in many body processes.

What's the fuss about potassium? 

Low potassium on a blood test is a known risk factor for sudden cardiac death. The routine blood chemistry range is 3.5 - 5.5 mmol/l. However, this is more about life/death scenarios and the medical literature on quality of life points to 4.5 - 5.5 as being an optimum potassium level and a level in the low 3s and 4s is a cause for concern. Even 4.1 or 4.2 can reflect an increased risk of heart dysfunction.

Hence, where potassium levels are consistently below 4.5, this tells us that there are things interfering with potassium metabolism and that we should be looking for cardiac risk factors. There is a need to look for metabolic imbalances driven by factors such as high stress, caffeine intake, carbohydrate intake, inflammation, infection, etc.

Why is low potassium a risk factor for sudden cardiac death?

Electrical signals from the central nervous system make muscles contract. The ability to contract is based on the relationship between water and the major electrolytes of sodium, chloride, calcium, potassium and magnesium and they need to be balanced.

One of the problems is that people often consume too much dietary sodium and not enough potassium and magnesium. Potassium isn’t added to processed foods in the same way as sodium but is found in good levels in whole foods, including green leafy vegetables, dried fruit, avocados, sweet potatoes, potatoes, mushrooms, coconut water, oranges and melons.

What are some common signs of low potassium?

• muscle cramping and twitching
• fatigue on climbing stairs/walking
• aching muscles/cramps - may trigger lactic acid
• digestive issues such as bloating and constipation
• heart arrhythmia
• high blood pressure

If potassium drops dangerously low, slurred speech, confusion and weakness can ensue.

Low potassium and cardiac issues

There is much medical research literature linking low serum potassium (hypokalaemia) and sudden cardiac arrest. Almost 50% of all fatal heart attacks are related to arrhythmias due to suboptimal fluid and electrolyte balance.

Additionally, significant stressors can rapidly reduce serum potassium levels. Although not much of a concern for the healthy population, as induced hypokalaemia will not last long enough to create an issue for a healthy heart. However, in people with a suboptimal heart function, a period as short as a few seconds could trigger ventricular fibrillation and possibly a life-threatening situation. Therefore, the accepted potassium range may be OK for the healthy population but tightens dramatically with heart dysfunction.

Magnesium and potassium should be supplemented together to get optimal results and restore potassium.

Geethavani et al. (2014) found that 400mg of caffeine (approximately 4 cups of coffee) over 2 hours has been found to significantly deplete potassium.

The dark side of fasting

Those liberated from the concentration camps in World War 2 were given anything to eat the soldiers could lay their hands on (such as chocolate bars and biscuits), resulting in the sudden death of around 500 prisoners from Auschwitz and 14,000 from Belsen. This is due to a sudden spike in insulin from a sugar rush or stressful event increasing cortisol. This causes increased potassium moving into the cells and a sudden decrease in potassium in the circulation.

In susceptible people, this can result in tachycardia (increased heart rate), arrhythmia and even death. This is relevant if you haven’t eaten for quite a while. This is the dark side of fasting which has become fashionable in recent times. The key message is don’t fast if you are eating a junk food diet to avoid the dangers of this syndrome.

Track your potassium levels 

If you have a heart condition, monitor your potassium level along with your other electrolytes. Make sure you eat regularly. If you have not eaten for several hours and your health is not that good, don’t break your fast with a cake and a coffee, otherwise you risk a sudden potentially dangerous potassium imbalance.

Tracking your potassium level is paramount. However, a low reading on a lab test usually means imbalance and not necessarily deficiency - too much in the cell, too little in the blood.

Are lifestyle changes important?

Lifestyle changes, are just as important as supplementation. Consider a balanced natural diet, managing blood sugar regulation, low/no caffeine consumption, avoid refined sugars and alcohol, stress levels and balance levels of other electrolytes such as magnesium. Find out why your potassium is low and work on those factors.

Is only low potassium a problem?

No, you can get the situation where potassium is too high and this is just as much a medical emergency. Hyperkalaemia (high potassium) can occur for different reasons but namely due to kidney disease. Since the kidneys balance the amount of potassium in the body, severe kidney disease often means the kidneys cannot get rid of this mineral quick enough. Other causes may be a diet high in potassium especially largely foods such as cantaloupe, honeydew melon, orange juice, and bananas. Drugs that prevent the kidneys from losing enough potassium also cause levels to rise.

For help with this condition, seek advice and support from a naturopath or/and nutritionist.