Long covid: Three fundamental dietary steps to accelerate recovery

Nearly 2 million people in the UK have been diagnosis as suffering the consequences of long covid in the last year. The exact cause of prolonged post viral symptoms remains unresolved but the two main theories are either a persistent grumbling virus which never adequately cleared or a chronic abnormal immune response which starts attacking the hosts own body cells – a form of autoimmune disease.

A study published this week showed that depression is a major factor in long covid but other common symptoms include, fatigue, poor memory, lack of motivation, insomnia, and joint and muscle aches.

During the outbreak, scientific communities across the world raced to find the licenced drugs, from vaccines to antiviral medications, but some also addressed dietary and lifestyle factors. I was honoured to be chief investigator of a major clinical study conducted in the height of the pandemic which involved patients with long covid that evaluated dietary interventions.

As well as the participants in the study, we interviewed and learnt from hundreds more covid sufferers during the recruitment period. After analysing the data we then shared knowledge and experiences with other research colleagues from across the world.

From this, we learnt that, as well as age, being overweight, smoking, being sedentary, having concomitant medical conditions such as diabetes, hypertension and airways disease, three pivotal dietary-related factors stood out, as influencing the severity of covid and whether a person went on to develop long covid namely:

1. Poor Gut Health

It became clear, from scientific studies, that healthy strains of gut bacteria such as Lactobacillus were depleted in the majority of patients with Covid. This caused an imbalance of gut bacteria (microfloral dysbiosis) which then contributed to worse covid damage to the whole body via increased gut inflammation, impaired gut wall integrity, which leads to systemic inflammatory dysfunction and reduced immune surveillance.

The UK Zoe app team also reported that people taking probiotics, which aimed to improve gut health, had fewer covid symptoms.

Tips to improve gut health: Avoid taking antibiotics, non-steroidal anti-inflammatory drugs or antacids unless absolutely necessary. Try to exercise every day, quit smoking, cut down on processed meats and sugar and ramp up the prebiotic intake of mushrooms, beans, nuts and seeds. Introduce more foods into the diet which have live health bacteria such as fermented, pickled foods, live yoghurt, kefir, miso soup, tempeh and Kimchi.

2. Ensuring adequate Vitamin D levels

It took a while for the penny to drop, especially in view of the obvious correlation between Black and Asian people in northern climates having worse covid. As the pandemic proceeded, evidence started emerging that vitamin D had an important role in covid severity.

The Zoe app team, for example, reported that people taking regular vitamin D had less severe Covid. Other studies from China and the USA confirmed that people with below normal levels of vitamin D had higher risks of hospitalisation and going on to develop long covid.

This relationship was confirmed by the massive prospective UK Biobank study, which found a strong association between low serum vitamin D with Covid-19 severity, even considering and adjusting for obesity and ethnicity. People with low vitamin D tend to react to the virus with an excess inflammatory response, which results in greater tissue damage and hence overall more severe symptoms. They also tend to have an impaired immunity so the virus is cleared from the system at a slower rate.

Tips to improve Vitamin D levels: Skin produces almost 80% of the body’s vitamin D so try to exercise outdoors, even in the winter try to expose some skin to the sunlight. Do remember that that excess sunlight, is the main cause of skin damage, premature ageing and skin cancers so it's important not to let the skin get red or particularly sunburn.

Some foods contain a small amount of vitamin D such as free range eggs, oily fish and sundried mushrooms. Over the winter months, unless you have the luxury of one or two holidays in the sun, it would be sensible to take a vitamin D3 supplement at a dose of around 1000IU (25 micrograms) per day.

More recently, it has been discovered that vitamin D also acts as a prebiotic which supports the growth of healthy bacteria. Conversely, healthy bacteria improve the absorption and bioavailability of the vitamin, which is why the most effective vitamin D supplements are mixed with probiotics.

3. Phytochemical-Rich Foods

Phytochemicals provide the colour and aroma of edible, generally tasty, plants but also have enormous health benefits. Higher intake has been linked with a reduced risk of many chronic diseases, better exercise performance, lower fatigue levels, improved mood, sharper mental agility. Previous and ongoing studies have shown boosting phytochemical intake is linked to lower risk of cancer and slower progression.

In terms of covid, laboratory research shows they have direct antiviral properties by reducing replication and blocking the spreading of the virus. The phytochemical demonstrating the best results were curminoids (in turmeric); resveratrol and citrus flavonoids; ellagic acid and quercetin (pomegranate) and apigenin (chamomile, parsley, and celery).

Resveratrol has also been shown to help reduce virus-induced exudate production in the lung. All these phytochemicals also have the ability to dampen excess inflammation, which explains why they help reduce inflammation-associated joint pains, a symptom common among people with long Covid.

But, unlike aspirin and ibuprofen, have actually protect gastric mucosa, kidneys, and the heart. Furthermore, unlike steroids and other immune suppressants, the ability of phytochemicals to suppress inflammation does not lead to a reduced viral immune response.

How to increase phytochemical rich food intake: The biggest group called polyphenols, are abundant in vegetables, salads, herbs, spices, teas, nuts, fruits, mushrooms, seeds and legumes.

The typical western diet, is often deficient in phytochemicals, meaning we need to think about eating a lot more of them. Ideally, we should aim to have two or more vegetables, fruit or other phytochemical rich foods with every meal of the day.

The national covid, nutritional intervention study aimed to explore all three dietary strategies - to improve gut health, vitamin D and phytochemical rich food intake. To achieve this, it used two supplements, the first contained a combination of 5 phytochemical rich foods (chamomile, resveratrol, citrus bioflavonoids, pomegranate and turmeric) which after the trial finished became known as Phyto-v.

The second contained a blend of 5 Lactobacillus probiotics together with a prebiotic called inulin and vitamin D, which after the trial became known as Yourgutplus.

Although the emphasis in any dietary intervention should be to improve whole food intake, in the busy world we live in, a well-made supplement, for some people, is a convenient way to increase phytochemical and probiotic intake and spread intake across the day.

An analysis of the final results, by Bedford University, showed a 2-fold reduction in fatigue, cough, breathlessness, and an improved overall quality of life after taking the Yourgutplus capsule. This was certainly welcomed, especially among those who had suffered for over 100 days and especially those with gut problems in whom the overall benefit was greater.

For those randomized to the additional Phyto-V capsules, the gain was even greater, with a further three-fold improvement in symptoms compared to the placebo group. There was particularly good improvement in natural sleep patterns. The final research papers were published in the prestigious international journal COVID, received widespread media attention and the supplement is now used in many long covid clinics across the world.

In conclusion, although anti-viral medical strategies are continually being explored, there are clearly some evidence based self-help strategies which can certainly help. These dietary changes are, however, not a quick fix, do not help everyone affected but also have the advantage of instilling a sense of empowerment and hope in people whose lives have been devastated by this illness.

What's more, they aim to improve our body's defences against virus for the longer term so should be a considered as a permanent behavioural change, alongside other health habits such as exercising more, maintaining a normal weight, adopting sleep hygiene practices, stopping smoking, eating less processed meat and processed sugar.

So, as well as helping in the tail end of the current pandemic they, hopefully, will better prepare us from the effects of the next one - the dreaded Disease X.