Good nutrition is essential in helping the body recover from illness, including long Covid recovery. Steven Pearson-Brown looks at the diets occupational health professionals could recommend for employees with lingering coronavirus symptoms.
Nutrition plays an essential role in our body’s ability to defend against and recover from infection. Whilst a healthy and balanced diet is the principal factor, there are some nutrients which play a particularly important role.
The common symptoms of long Covid can impact nutritional intake (Davis, et al., 2021) including:
- systemic and musculoskeletal: fatigue, post-exertional malaise and pain
- neuropsychiatric: sleep disturbance, dizziness, low mood and anxiety
- gastrointestinal: nausea, diarrhoea, anorexia and reduced appetite
- cardiovascular: breathlessness, myalgia, and cough – myocardial injury is the most common complication, thus self-monitoring blood pressure and pulse oximetry may help
- genitourinary and endocrine: liver dysfunction and symptoms related to urinary function. Low and high blood glucose levels may also be common.
People with long Covid may continue to have periods of anosmia (loss or changed sense of smell) or ageusia (loss of sense of taste), impacting on their desire to eat or drink. They may also struggle with suitable nutrition due to fatigue impacting on the ability to shop for food, prepare and cook food, and even to eat food. This fatigue may be a symptom of long Covid or the result of other symptoms, such as sleep disturbance.
Adequate nutrition provides the body with all the nutrients it requires. These needs may be greater in people with long Covid, due to them being in the recovery period.
The body’s response
During infection the body will draw proteins from the muscle and breaks them down into amino acids to create new proteins for the immune system. This will continue into the recovery stage, meaning the individual may have an increased protein requirement. Without enough protein the muscles may atrophy, increasing feelings of fatigue and weakness.
Protein sources such as beans, pulses, nuts, and seeds are also a source of fibre – vital for gut health which can be negatively impacted during and after infection with Covid-19. Research has shown a relatively high expression of ACE2 receptions in the small intestinal enterocytes (Mao, R. 2020), which can be targeted by Covid-19 and result in dysbiosis (Gu, S. 2020), a common finding in those with long Covid and gastrointestinal symptoms. It is believed that the dysbiosis, also found in several other chronic inflammatory conditions (Dickson, R.P. 2016), results in a reduction in the diversity of the microbiota, impacting immunity. Including fibre-rich foods as well as sources of pre- and probiotics may be beneficial to re-establish a balanced and diverse microbiome and potentially alleviate gastrointestinal symptoms (Yeoh, Y.K. 2021).
Individuals will require plenty of energy. Carbohydrates are the primary source for the body, and these should be from wholegrain starchy sources rather than refined or sugary sources. This will also ensure an intake of soluble and insoluble fibre, but also a slow release of energy, supporting the regulation of blood glucose levels, preventing large swings from high to low blood glucose – which can impact on mood, energy levels and concentration. Combining wholegrain carbohydrates with a source of protein can also help balance blood glucose.
Protein sources such as beans, pulses, nuts, and seeds are also a source of fibre – vital for gut health which can be negatively impacted during and after infection with Covid-19.”
Which diets benefit people with long Covid?
The British Dietetic Association, citing information the University of Plymouth, recommends that individuals follow the Mediterranean or the NHS Eatwell Guide diets. The Mediterranean diet is an “anti-inflammatory diet, potentially advantageous given those with long Covid have a continued inflammatory response post infection” (British Dietetic Association, 2020).
This approach includes consuming at least five portions of fruit and vegetables a day, with wholegrain sources of carbohydrates forming the basis of meals and low-fat protein sources including beans, pulses, nuts, seeds, fish, eggs and meat being consumed regularly. Variety is important to ensure that key nutrients are consumed, such as omega-3 from oily fish and walnuts (British Dietetic Association, 2019).
For individuals who are overweight, obese, or those with an elevated waist circumference, weight loss could be beneficial.
Recent research has indicated the potential for using an intermittent fasting (IF) approach, with some evidence supporting the benefits for those with long Covid (Ealey, K. N et al, 2021). IF can be done in several ways, the most common including time-restricted feeding (TRF), such as the 16:8, where individuals only consume food within an eight-hour window and fast for the other 16-hours, or the alternative day fasting (ADF), such as the 5:2, where individuals consume only 500 Kcals on two non-consecutive days and the remaining five days on normal diet of around 2,000 Kcals per day.
The IF approach is founded on some evidence to show a reduction in key immune factors, including cytokines, TNF-a, IL-6. and IL-1B (Faris, M.A., 2012). Additionally, it can result in a reduction in fasting glucose levels, insulin concentration, adiposity and increased sensitivity to glucose and insulin and circulating levels of GLP-1, the latter being a hormone involved in appetite regulation; high levels are associated with a decline in appetite and reduction in energy consumption (Ealey, K. N et al, 2021).
Beware of weakened immune systems
IF, ADF and/or TRF are not going to be suitable for everyone. For those where a decrease in energy intake may be less desirable, due to weight loss and/or suppression of the immune system, will hinder the immune response (Duriancik D.M, 2018). In a study reviewing TRF on overweight older adults, the author says caution should be used when advising those over 65 years and those with a weakened immune system to follow a fasting dietary regime (Anton S.D., 2019).
Irrespective of the situation, the diet should contain at least five portions of fruit and vegetables, wholegrain sources of carbohydrates, lean sources of protein, good amounts of fibre and at least 1.5-2L of water a day.”
Some people with long Covid may have lost weight during their infection due to the increase metabolic demands of the infection and the continued elevated demands during recovery. This weight loss may have been significant and anosmia and ageusia may potentially have contributed to it. Rapid weight loss can result in malnutrition, irrespective of a person’s original or current body mass index. These individuals need to be encouraged to increase their food consumption to ensure that their body gets the nutrients it requires. It is likely that energy intake will need to increase if the person is continuing to lose weight, or intake is very small. Input from a GP or dietitian may be recommended and supplements may be beneficial.
Irrespective of the situation, the diet should contain at least five portions of fruit and vegetables, wholegrain sources of carbohydrates, lean sources of protein, good amounts of fibre and at least 1.5-2L of water a day.
There is some discussion around the role of a low-histamine diet possibly being beneficial for individuals with long Covid. This is on the premise that the person’s body has become sensitive to histamine due to increased exposure during the infectious period and therefore is unable to breakdown histamine in food. There is currently no evidence to support this theory and the British Dietetic Association currently advises against it due to the complexity of following this diet, the time-consuming process required to prepare meals, and the diet going against the principles of the Mediterranean diet, which currently is the most widely held example of a healthy, balanced diet (British Dietetic Association, 2021).
Most promising diet
Whilst there is more research to be done to determine which (if any) dietary intake is the best for those with long Covid, the evidence does indicate that the Mediterranean diet is the most promising. This dietary approach is the most researched, showing clear indications for benefits to long-term health, reducing risk and incidence of cardiovascular disease and other chronic health conditions.
Incorporating nutritional screening into the long Covid service, getting a clear understanding of the individuals’ circumstances and challenges, can create a positive therapeutic environment. Dietary advice should be person-centred and for complex individuals, referrals for dietetic support can be beneficial to improve multiple areas of their health. Occupational health has an opportunity to support the whole person, ensuring they are listened to and heard.
The PAM Group has developed a specialist service to support individuals suffering with long Covid. The service utilises the expertise of the psychotherapy team, psychological services, health and wellness experts and is overseen by occupational health advisors, in the capacity of case manager. The health and wellness team were a recent addition to the service, due to observations that many individuals referred were struggling with changes to appetite, food and hydration intake, physical activity, and sleep.
Davis, H.E., et al. (2021). Characterising long COVID in an International Cohort: 7 months of Symptoms and Their impact. medRxiv, p. 2020.12.24.20248802. doi:10.1101/2020.12.24.20248802
Mao R. Manifestations and prognosis of gastrointestinal and liver involvement in patients with COVID-19: a systematic review and meta-analysis. Lancet Gastroenterol. Hepatol. 2020;5:667–678.
Gu S. Alterations of the gut microbiota in patients with coronavirus disease 2019 or H1N1 influenza. Clin. Infect. Dis. 2020;71:2669–2678.
Dickson R.P. The microbiome and critical illness. Lancet Respir. Med. 2016;4:59–72.
Yeoh Y.K. Gut microbiota composition reflects disease severity and dysfunctional immune responses in patients with COVID-19. Gut. 2021;70:608–706.
British Dietetic Association (2020). Long covid and diet. [Online] available at: https://www.bda.uk.com/resource/long-covid-and-diet.html
University of Plymouth Nutrition and COVID-19 Recovery Knowledge Hub [Internet] (https://www.plymouth.ac.uk/research/dietetics-and-health/covid-knowledge-hub; Prof Calder Nutrition and COVID-19 Recovery: Is there an anti-inflammatory diet? Available from: https://www.youtube.com/watch?v=r7A-cONFir4
British Dietetic Association (2019). Omega-3 Food Fact Sheet [online]. Available at: https://www.bda.uk.com/resource/omega-3.html
Faris M.A. Intermittent fasting during Ramadan attenuates proinflammatory cytokines and immune cells in healthy subjects. Nutr. Res. 2012;32:947–955
Ealey, K. N., Phillips, J., & Sung, H. K. (2021). COVID-19 and obesity: fighting two pandemics with intermittent fasting. Trends in endocrinology and metabolism: TEM, 32(9), 706–720. https://doi.org/10.1016/j.tem.2021.06.004
Duriancik D.M. Age, calorie restriction, and age of calorie restriction onset reduce maturation of natural killer cells in C57Bl/6 mice. Nutr. Res. 2018;55:81–
Anton S.D. The effects of time restricted feeding on overweight, older adults: a pilot study. Nutrients. 2019;11:1500. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6682944/
British Dietetic Association (2021). Low histamine diet and long covid. [online] Available at: https://www.bda.uk.com/resource/low-histamine-diets-and-long-covid.html