If the cold rain and blistering wind are not a sure sign that this winter is a harsh one, then the number of people sneezing and coughing surely is.

When asked about their ailments, most people will blame sickness on overdoing it, getting little sleep and not eating properly due to work, kids, festivities and life in general. It seems that these afflictions creep in on us in times of stress and when we are pushing ourselves too hard.

However, why does bad health hit us particularly hard in winter? The reason is that cold temperatures thin our nasal lining, leaving us more susceptible to infection. There are more than 200 viruses that enter our body and can infect the cells in the nose: this can then send inflammatory alarms to the body to produce more white blood cells.

Science backs up this observation too. When we’re stressed, the immune system’s ability to fight off foreign bodies – or antigens as they are called – is reduced. The stress hormone corticosteroid can also suppress the effectiveness of the immune system by lowering the number of immune cells. This is why we are more susceptible to infections when we are stressed. This means that less stress leads to having a better immune system and therefore less sick days. It’s simple really.

So where does yoga come into all this? First of all yoga provides a gentle, natural means of supporting the immune system on a daily basis, no matter how hectic your schedule is. Yoga helps lower those pesky stress hormones – corticosteroids – that compromise the immune system, while also conditioning the lungs and respiratory tract, stimulating the lymphatic system to oust toxins from the body and bringing oxygenated blood to the various organs to ensure their optimal function. Unlike other forms of exercise that only focus on certain parts of the body, yoga works on everything.

Research published in 2013 by the University of Oslo helps explain the health benefits of this ancient practice. “Data suggests that previously reported [therapeutic] effects of yoga practices have an integral physiological component at the molecular level, which is initiated immediately during practice,” wrote a research team led by Fahri Saatcioglu. The team’s study was published in the online journal Plos One.

The University of Oslo experiment featured 10 parti­cipants who attended a week-long yoga retreat in Germany. For the first two days, participants spent two hours practising a comprehensive yoga programme including yogic postures (asanas), yogic breathing exercises and meditation. For the next two days, they spent that same time going on an hour-long nature walk and then listening to either jazz or classical music.

Immediately before and after each of the four sessions, the researchers drew blood from each participant. They then isolated and analysed peripheral blood mononuclear cells, which play a key role in the body’s immune system. The researchers found that the nature walk and music-driven relaxation changed the expression of 38 genes in these circulating immune cells. In comparison, yoga produced changes in 111 genes.

The researchers noted that yoga’s impact was far more widespread, which indicates the practice, “may have additional effects over exercise plus simple relaxation in inducing health benefits through differential changes at the molecular level”. It looks like walking in nature is good but fitting in a yoga practice while you are out there by the sea is substantially better.

Any style of yoga will help boost your immune system by lowering stress levels. However, there are some postures which are especially suited to giving your immune system a helping hand in the winter months. If you already follow a yoga practice you might like to include more of these asanas.

A pose for health

Downward dog pose: promotes circulation, helps to move white blood cells throughout the body, and helps to clear out the sinuses.

Cobra pose: stimulates the thymus gland.

Bridge (wheel) pose: opens and expands the chest area, which also stimulates the thymus gland and improves circulation.

Bow pose: this pose also stimulates the thymus gland by opening up the chest.

Cat-Cow pose: helps improve circulation and clear congestion in the respiratory tract.

As with any new practice regime you should seek experienced supervision and medical advice when attempting any yoga disciplines.

Sveta Abela is founder of PowerYogaWorld.

www.poweryogaworld.com