Stress may make it harder to fight off sickness

It’s long been thought that being under stress can make us more likely to get sick and now Australian scientists have discovered evidence that may back this idea up.

In a trial on mice, the researchers discovered nerve signals, in response to stress, can stop immune cells from effectively fighting pathogens and tumours.

The study published in the journal Immunity found, using live-cell imaging, that immune cells stopped moving when the host was under stress.

During an acute stress response, blood flow is redirected to the muscles, to enable the ancient ‘fight or flight’ response to a perceived danger. When this blood flow redirection occurs, immune cells stop moving as they normally would and the ability to fight off disease-causing organisms is impaired.

The changes are not permanent, according to lead researcher Scott Mueller, but stress does appear to dramatically change immune system response.

“We know, anecdotally, that when we are stressed, we are more likely to get sick, but exactly why this occurs has been difficult to define, until now. The imaging showed us that stress caused immune cells to stop moving, preventing them from protecting against disease,” Professor Mueller explains.

“Movement is central to how immune cells can get to the right parts of the body to mount an immune response against infections or tumours, so it was surprising to see that the stress signals had such a rapid and dramatic effect on how immune cells move around,” he says.

Study limitations

The nerve signals that stopped the immune cell movement were only in response to significant stress but the type of stress, eg, shock or chronic psychological stress, that causes the response is still unclear.

The findings need further investigation because it was an animal trial, and the researchers say their next steps will be to find out if the nerve stress signals they observed suppress immune responses to cancer.

Why managing stress is important

Aside from the potential effect on immune response to pathogens, chronic stress, if not managed properly, can increase your risk of health problems such as hypertension, heart disease and stroke, erectile dysfunction and impotence in men, and irregular or absent menstrual cycles in women.

Stress is not all bad. It is a motivator and can help us be productive and perform better. But when stress is chronic or feels like it’s getting out of hand there are some simple things you can do to manage your stress levels before they escalate.

1 Work on the fundamentals

Maintaining a healthy diet, exercising regularly, building healthy relationships, participating in interests outside work and maintaining a sense of meaning and purpose are all a good foundation for keeping the balance in life needed to manage stress effectively.

2 Fill your cup and unwind

Try to schedule in regular activities that ‘fill your cup’ and help you unwind such as yoga, dancing, reading a good book, taking a hot bath, walking in nature or catching up with supportive friends.

3 Practise self-compassion

Treat yourself kindly and try not to be overly critical of yourself, especially when you are under pressure. Self-care can be as simple as taking microbreaks throughout the day, switching your notifications off on your phone for a couple of hours and making decisions now that will benefit your future self.

For more on stress, you might be interested in Habits that build resilience and manage stress.