Viruses and other pathogens can attack us easily if our immune system is weakened. Covid-19, for example, has been observed to affect people who already have health complications, suffer from an illness or have a depleted immune system.

Given the scale and contagion of the global pandemic, a healthy lifestyle is no guarantee against infection. However, taking steps to stay healthy and strong can make it harder for pathogens of any kind to enter your body.

Here are some simple measures you can take to keep your guard up and strengthen your body’s defenses body during the Corona crisis.

Sleep sufficiently
Studies show that the production of immune cells increases while you sleep, which is crucial for successfully fighting bacteria and viruses.

It is important each night to give your body enough time to complete a full sleep cycle – generally about eight hours. A full sleep cycle ensures that numerous vital hormones are released. This cycle begins with the production of melatonin and ends with the release of prolactin[1]. These two hormones promote the creation of immune cells. As melatonin is only produced in the dark, it is important to keep the room you are sleeping in as free of light as possible[2].

Chronic sleep deprivation can lead to aggravating symptoms such as high blood pressure and gastrointestinal problems[3], which in turn deplete your immune system.

Drink enough water
The human body is mostly made up of water. However, body hydration decreases over the course of a lifetime. A newborn child has a water content of 70-80 per cent whilst an 85-year-old person only has 45-50 per cent water[4]. Most of this water is not found in the blood, but in the body’s cells. As we age, our percentage of fat increases, while the percentage of water decreases. Fluid is constantly excreted through the skin, intestines, kidneys and while breathing.

Those who drink too little water are not only more fatigued, but also more susceptible to infections. One of the reasons for this is linked to mucous membranes, which dry out and, due to a lack of moisture, are not able to fend off attacking viruses and bacteria effectively. Adults are recommended to drink a least 1.5 liters of water a day[5].

Drinking tea can also have a positive effect on your immune system. Green tea in particular contains many antioxidants that support immunity and may play a role in reducing the risk of some cancers[6].

Boost NAD+
A molecule called NAD+ plays a critical role in hundreds of processes which keep your cells healthy and has a significant impact on many different pathways of immunity. The older you get, the more NAD+ is needed to help repair and power your cells – which why NAD+ levels decline with age.

Fortunately, there are ways to replenish your NAD+ levels. The most direct way is by supplementing with other molecules your body uses to create NAD+.

As the final step in the biochemical chain reaction that produces NAD+, a molecule called NMN is a highly efficient route to restoring NAD+ levels. This, in turn, supports vital molecular pathways that keep your body running well.

NMN occurs naturally in all life forms and fuels essential functions of cells, such as how they generate energy and protect and repair your body. It helps boost immunity and protect against the chronic inflammation that comes with aging[7]. It also contributes to a more effective immune response.

Eat a balanced diet
A healthy diet is a vital ingredient in strengthening your immune system. It is important to eat food that is high in vitamins A, B, C, D and E and essential minerals such as iron, zinc and selenium.

B vitamins can be found in large quantities in green vegetables such as broccoli and spinach. They are also present in beans, bananas, eggs, poultry, fish and beetroot. B vitamins are important for our brain to release ‘happiness hormones’ – serotonin and dopamine. A contributor to depression can be a lack of B6, B12 and B9 (folic acid).

The state of our intestines also has a strong influence on our mood and psychological well-being. Prebiotics and probiotics contained in fermented foods such as kefir, tempeh, sauerkraut, kimchi and yoghurt have anti-inflammatory effects. They can also improve mood and cognitive functions[8]. Meanwhile, ginger, oregano[9] and onions[10] are known to be helpful in improving lung function, as their essential oils dissolve mucus (one of the first lines of defense against viruses).

Recent studies have shown that when we eat may also be as important as what we eat. Intermittent fasting (taking eating breaks) can relieve the intestinal immune system, helping to reduce chronic inflammations of the intestinal mucosa. It can also help your body to remove toxins better[11].

Research ha also shown that limiting calorie intake by 20 to 30 per cent by fasting intermittently can increase NAD+ levels and improve SIRT1 activation (which aids metabolic and aging processes)[12].

Exercise
Practicing a regular form of exercise makes the body more resilient. Endurance sports such as jogging, walking, cycling or swimming are particularly effective in supporting immunity.

Taking part in endurance exercise causes the number of some immune cells in the bloodstream to increase by up to 10 times, especially ‘natural killer cells’ which deal with infections. Recent studies also show that endurance exercise increases cell activity and contributes to a higher NAD+ level[13], which in turn delivers benefits to immunity.

Not everyone is able to undertake strenuous exercise. Happily, exercises that strengthen the lungs through conscious breathing techniques, such as yoga and stretching, can also deliver positive health benefits[14].

According to the World Health Organization (WHO), adults should exercise moderately for at least 150 minutes per week to see positive effects. The European Respiratory Society (ERS) recommends that people with respiratory diseases exercise between 20 and 60 minutes five times a week[15] if possible.

Get some vitamin D
Vitamin D is the only vitamin that can be synthesized by the body itself. So, strictly speaking, it does not meet the definition of a vitamin. This is why it is increasingly referred to as D hormone[16].

Whatever you call it, vitamin D is especially known for its bone-strengthening effect as it promotes the absorption of calcium from the intestines. It is involved in the incorporation of calcium into the bones, inhibits bone resorption and at the same time strengthens the immune system[17].

Vitamin D is produced in the skin by sunlight (excluding UVB radiation). However, the formation of vitamin D in the skin is influenced by various factors: in winter, the intensity of the sun is not sufficient to produce enough vitamin D in the skin, while your ability to produce vitamin D decreases by up to four times as you age.[18] You can help to top up shortfalls in your Vitamin D with diet – it is found in foods such as salmon, liver, avocado and mushrooms.

Control stress
Research has shown that severe stress weakens the immune system and thus increases your susceptibility to infections[19]. Chronic stress can also lead to a state of exhaustion, which – just as with physical overload – provides ideal conditions for pathogens to multiply[20]. It is important to control stress levels as much as possible and use quieter hours for targeted relaxation.

Keep Your Social Life Going
With its limitations in everyday life, lack of direct contact with family and friends, and financial worries for many, the global pandemic continues to create stress and psychological impacts which can manifest physically.

Social health has been undermined by distancing, isolation and lockdowns. Knowing that socializing impacts our physical health, mental health and mortality risk, it’s more vital than ever for people to feel connected and supported.

Today’s technology tools and resources, along with good old-fashioned phone calls, physically-distanced walks (where and when rules allow) and even greeting cards and letters, can help. Staying socially healthy will benefit your physical and mental health, and your overall quality of life will reflect it.