Viral infections are an inevitable part of life. Thankfully,  most find that symptoms pass swiftly after the initial illness; however, fatigue and other after-effects linger on stubbornly in some. In this article, we focus on the fascinating role of mitochondria in energy production and the nutrients they need to keep you going.

Termed ‘long Covid’, a lack of energy and generally feeling unwell are emerging as particularly common post Covid-19, both among those who were seriously ill in hospital and those who had mild to moderate symptoms at home. Around 10% of those who have contributed to Dr Tim Spector’s Covid Symptom Study report effects lasting more than 4 weeks after infection. This fatigue causes difficulty in resuming previous activities, and makes returning to work extremely challenging.

Apart from tiredness, frequently reported symptoms after Covid-19 infection include difficulty with memory and attention, muscle aches, headaches, dizziness, raised temperature and persistent lack of smell.

Malaise is common after infections such as with Epstein-Barr virus, which causes glandular fever. Viral fatigue and insomnia are even more pronounced after SARS-1, with 60% of sufferers reporting these symptoms one year after catching the virus. Covid-19 differs from ‘ordinary influenza’  in that the fatigue is more likely to be accompanied by other distressing symptoms such as ‘brain fog’, a term used to describe a feeling that one just isn’t ‘oneself’ in terms of clear thinking, memory and focus.

Also known as ME (myalgic encephalomyelitis), CFS is a long-term illness characterised by extreme fatigue for at least 6 months, that doesn’t resolve with rest. It’s often accompanied by other symptoms such as muscle aches, headaches, difficulty thinking, remembering or concentrating, dizziness and insomnia. Symptoms vary from day to day and most sufferers find that over-exerting themselves makes them feel worse for a day or more afterwards. There are many possible triggers for CFS, such as viral & bacterial infections, emotional trauma, hormonal or immune system imbalance and mitochondrial dysfunction. Long Covid fatigue and other symptoms are very similar to those of CFS, and we may see many new cases of chronic fatigue being linked to coronavirus in the future. However, as one needs to be affected for half a year or more to entertain this diagnosis, it’s really too early to establish a trend.

As this pandemic is new and unknown, there are various speculations and research is rapidly evolving to improve our understanding. An ongoing low-grade infection in the lungs or brain is one theory. Others propose that an overreaction by the immune system with increased inflammatory compounds is causing ongoing damage to cells in key parts of the body. Research shows that the SARS virus infects the brain through the olfactory pathway. As Covid-19 often causes anosmia (lack of sense of smell), a similar phenomenon may be occurring with this coronavirus. (1)

Chronic fatigue, on the other hand, has been studied for decades. There has been significant research into factors that may cause mitochondria, the tiny energy-generating organelles present in each cell, to malfunction. What’s good for mitochondria is often also good for the brain and muscles; therefore, focusing on supporting mitochondria may benefit multiple symptoms of the post-viral syndrome.

These tiny organelles are found inside each human cell, and number over 2000 in hard-working cells! They actually evolved from bacteria and can be seen as ‘cells within cells’, co-existing with us in a symbiotic relationship. In return for nutrients and oxygen, these fascinating structures convert chemical energy from food into energy that our cells can use: adenosine triphosphate, commonly known as ATP. Healthy humans generate their own body weight in ATP each day! Because the body can’t store ATP, the mitochondria must produce it continuously. The brain guzzles around 70% of ATP, explaining why mitochondrial dysfunction can lead to a feeling of ‘brain fog’. (2) Mitochondria also have the power to influence which cells die, by releasing a toxic chemical that triggers programmed cell death. 

Energy production inevitably generates reactive oxygen species (ROS), including ‘free radicals’ which damage mitochondrial DNA and membranes. If only partially damaged, mitochondria have the remarkable ability to shed their injured part (fission) and join together with another in the same position (fusion), thereby maintaining a healthy colony. It’s more beneficial to have smaller numbers of healthy mitochondria, than a larger number that are dysfunctional. There is always a balance between the generation of reactive oxygen molecules and the ability of antioxidants in the body to deal with them - ‘oxidative stress’ occurs when the antioxidant system becomes overwhelmed.

Viruses are able to ‘hijack’ mitochondria and disrupt their function & communication, to the virus’s advantage. Covid-19 commandeers mitochondria, multiplying within and disrupting their fission and fusion. (3) By affecting iron metabolism, it also leads to increased reactive oxygen species which are directly damaging to mitochondria and cause them to release inflammatory compounds. (4)

Just as one can develop increased gut permeability, so-called ‘leaky gut’, so too can nutrient deficiencies cause the ‘pores’ in the mitochondrial membrane to become leaky, leading to inefficient energy production and distribution to the cell, and ultimately to mitochondrial and cell death.

ATP generation is a complex process involving many steps both within and outside mitochondria. Vital nutrients include:

Coenzyme Q10: the master antioxidant protecting mitochondria from damage. When CoQ10 is lacking (such as in those taking statin medication), less ATP is produced, causing tiredness, and free radicals generated by energy production damage not only the mitochondria but also leak out into the rest of the cell, causing oxidative stress. Resveratrol, selenium and vitamins A, C and E assist as antioxidants.

Glutathione (made from the amino acids cysteine, glutamine & glycine) ensure ATP production by keeping the mitochondrial membrane intact and protected from oxidative damage, as well as playing a vital role in detoxification.

Most of the B vitamins are crucial too - B1, 2 &3 assist enzymes in several steps of ATP production; B6 & 12 are essential for turning homocysteine into glutathione. Increased concentrations of homocysteine have been found in the cerebrospinal fluid of CFS patients.

Magnesium is involved in several steps of ATP production and ATP needs to be bound to magnesium to be biologically active. Furthermore, a magnesium deficiency results in the mitochondria not being able to pump ATP out into the cell for energy use.

α-Lipoic Acid & l-carnitine: carnitine carries fats into the mitochondria to be burned for energy, while α-lipoic acid assists in energy production and as an antioxidant. Used together, these nutrients increase ATP production.

It’s important not to over-exert yourself physically or mentally. Each day, decide what tasks are the most important to achieve, even if only preparing food and basic hygiene, and don’t feel like a failure if nothing else gets done. Even watching TV and spending time on your phone can be mentally taxing, so take frequent breaks for relaxing ‘screen-free’ activities such as listening to calming music, gentle breathing and meditation or just sitting quietly outside.

Be reassured that the fatigue is not ‘in your head’ and that most cases improve with time. Let family and friends know what you’re experiencing so that they are better able to support you. If you can get help with some of the more mundane tasks such as shopping and cooking, you may be able to plan an activity or two that you enjoy, to keep a bit of joy in your life.

Night-time insomnia can be helped by avoiding caffeinated drinks and long daytime naps.

If you have a job, when you feel ready to restart work negotiate a gradual return, working only a couple of hours per day at first.

Be kind to your health by supplying your body with wholesome nutrition and be realistic about how much you can take on each day as you gradually return to health. A lack of energy and a loss of appetite may make it difficult for you to get all the supportive nutrients you need from your diet alone. With a team of friendly nutritionists, we are happy to advise if you’d like guidance on supplements that may benefit you or your loved ones. 

1. Perrin R et al. Into the looking glass: Post-viral syndrome post COVID-19 [published online ahead of print, 2020 Jun 27]. Med Hypotheses. 2020;144:110055. doi:10.1016/j.mehy.2020.110055
2. Pizzorno J. Mitochondria-Fundamental to Life and Health. Integr Med (Encinitas). 2014;13(2):8-15
   
3. Singh, K et al. Decoding SARS-CoV-2 hijacking of host mitochondria in COVID-19 pathogenesis. Cell physiology. 2020;319(2) C258-C267 doi: 10.1152/ajpcell.00224.2020 
4. Saleh, J et al. (2020) Mitochondria and Microbiota dysfunction in COVID-19 pathogenesis Mitochondrion. 2020; 54:1-7 doi: 10.1016/j.mito.2020.06.008