DR MICHAEL MOSLEY: Stress can raise the risk of catching a bug, even cancer – and here’s how I tackle it

I suspect that, like most of us, I enjoyed the unexpectedly warm start to October – but I’m really not looking forward to the colder, darker months ahead, which are some of the most miserable and stressful of the year.

I have a naturally gloomy outlook (more Eeyore than Tigger) and am acutely aware of the effects of chronic stress on my body.

And managing stress is important, especially at this time of year when we are more vulnerable to increased infections, a recent study published in the journal Nature confirms.

Researchers from the Salk Institute in California showed that one way stress affects our health is that the stress hormone norepinephrine, an important part of our fight-or-flight response, binds to our killer T cells and depletes them.

Killer T cells are part of our immune system and are crucial for fighting viral infections and destroying cancers.

Killer T cells are part of our immune system and are crucial for fighting viral infections and destroying cancers, writes MICHAEL MOSLEY

Drinking a cup of tea after a stressful event lowered levels of the stress hormone cortisol, UCL researchers found in a study a few years ago

The good news is that researchers have also found that they can prevent this (at least in mice) with beta-blockers – drugs that are used to treat high blood pressure in humans but also reduce symptoms of stress and anxiety, such as heart palpitations.

Could adding beta-blockers to cancer-fighting therapies make them more effective? We’re not there yet as more research is needed – but in the meantime, here are some things I’m doing to reduce my stress levels and give my killer T cells a boost.

According to a survey reported by the Mail this week, putting the kettle on is one of our favorite ways to relieve stress.

And when it comes to what to drink to relieve stress, tea definitely seems to come out on top.

In a study published a few years ago in the journal Psychopharmacology, researchers at University College London showed that drinking tea after a stressful event reduced levels of the stress hormone cortisol.

Additionally, tea contains a compound called L-theanine, which has been shown to increase levels of a stress-reducing brain chemical called GABA. You could also try mindful tea drinking: the idea is that instead of picking up the phone and scrolling through the news or social media, you get a real break from your daily routine.

Put the phone away, pick up your cup, and really focus on what you’re doing. Feel the sensation of warmth in your hand, sniff the brew, and then drink it slowly, paying attention to the taste and aroma. I find that doing this for a few minutes is a great way to distract myself from the worries of the day.

Most of us enjoy a good hug with friends or loved ones, and there is plenty of research that shows that hugs are a great way to reduce stress, not only because touch provides comfort, but also because through hugs we can express our feelings Signal support for others.

In a rather strange experiment published in the journal Psychological Science in 2006, 16 married women were asked to enter a brain scanner and receive unpleasant electric shocks. This understandably stressed her out.

But when they held hands with their husbands, who were outside the scanner, their stress levels dropped – and major changes occurred in areas of the brain involved in regulating emotions. Strangely, the scientists didn’t look at what would happen if the roles were reversed.

So how long and how often should you hug? In a study published in 2003 that asked people to give a public speech, a 20-second hug just beforehand was enough to significantly reduce their stress levels.

When I’m out and about and feeling stressed, I often crave a bar of chocolate or cookies. But instead, I either try to suppress the urge or buy sugar-free gum. Chewing seems to reduce stress and ease my cravings, and there’s some science behind it.

In a 2012 study published in the journal Appetite, researchers at Cardiff University asked students to fill out questionnaires to assess their levels of stress and anxiety – over the following two weeks, one group chewed gum while the other abstained. It turned out that the more students chewed, the greater the stress reduction. Animal studies suggest that chewing stimulates brain cells involved in emotional regulation.

It’s no surprise that exercise is a great way to relieve stress – but a walk in the countryside seems to be particularly beneficial, according to research.

Research from 2003 found that a 20-second hug was enough to significantly reduce stress levels

And if possible, make sure that at least part of your walk goes through a forest. Because when you’re surrounded by trees, you inhale phytoncides – essential oils they release that have been shown to improve mood and strengthen our immune system.

In a recent study from Hanseo University in Korea, 55 patients being treated for cervical or breast cancer were randomly placed in either a room scented with tree oils or a room unscented for one hour a day, five days a week for two months.

At the end of the study, participants in the scented room saw a much greater decrease in their cortisol levels and an increase in cancer-fighting immune cells.

Sniffing lavender oil might also be helpful. A small study from Fooyin University in Taiwan showed that stress levels were halved in nurses who had small bottles of 3 percent lavender oil pinned to their clothing (while nurses with small bottles filled with just water were just as stressed as before ).

And then there’s my daily cold shower, which I’ve written about a few times before: Not only is it good for immunity, studies have shown that taking yourself repeatedly subjected to the mild stressor of cold water immersion.

I do this for about 40 seconds and sing loudly, which helps further reduce pain and stress (singing increases the release of endocannabinoids, a feel-good chemical in our body).