Stress could leave you at risk of infections by ‘weakening’ the immune system

Stress can impact our immune system, new research has suggested. (Getty Images)
Stress can impact our immune systems, new research has suggested. (Getty Images)

Stress is an inevitable part of life. At some point, everyone will feel stressed, whether it’s due to career, family life, money or other personal issues.

According to a study from the Mental Health Foundation, a huge three quarters (74%) of people have felt so stressed they have been “overwhelmed or unable to cope”.

But new research has revealed that stress could actually be making us sick.

Researchers at McMaster University in Hamilton, Canada, have found that feeling stressed could leave people vulnerable to disease by weakening their immune systems.

Read more: Are you suffering from RSF (Resting Stress Face)? Here's how to fix it

Scientists believe those suffering from stress could be at risk of developing Crohn’s disease as their body cannot keep harmful bacteria at bay.

When people feel under pressure or overwhelmed, their body produces hormones such as adrenaline or cortisol, but researchers have found some of these hormones could jeopardise the gut's defences.

Senior author Professor Brian Coombes says that psychological stress impedes the body’s ability to fight off gut bacteria that may be implicated in Crohn’s disease.

"Innate immunity is designed to protect us from microbes that do not belong in the gut, like harmful bacteria," he explains.

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(Getty Images)
Stress could leave people vulnerable to disease by weakening their immune systems. (Getty Images)

The gut is normally protected by a barrier of cells, known as epithelial cells, which keeps harmful microbes at arm's length.

But these gut guardians depend on immune cells being able to emit molecular signals to do their jobs.

In this particular study, published in the journal Nature Communications, researchers carried out a series of experiments on mice to see how stress affected their immune system.

They found that stress hormones blocked molecular signals from immune cells, breaking down the barrier, which would normally keep harmful bacteria out — specifically, a group of harmful bacteria known as Enterobacteriaceae, which includes E.Coli and has been associated with Crohn’s disease.

Professor Coombes adds: "When our innate immune system functions properly, it prevents harmful bacteria from colonising us, but when it breaks down, it leaves an opening for pathogens to colonise locations they normally cannot (access) and cause illness.”

When the stress hormones were removed, the rodents' immunity against the microbes was restored, the researchers found.

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While the findings are at a pre-clinical stage, the research team hopes they could lead to new treatments for Crohn’s disease. Around 115,000 people suffer from Crohn’s in the UK, a lifelong condition which causes inflammation of the intestine, ulcers and scarring in the digestive system.

While its root cause remains a mystery, patients often have large amounts of harmful bacteria like E. coli in their guts.

"The more we know about what triggers Crohn’s disease, the closer we come to new treatments and potentially even disease prevention," Professor Coombes adds.

Watch: Nearly 20% of those over 30 are constantly stressed.

The new research comes after scientists previously warned long-term stress could leave you at risk of infections. The “continuous” release of the stress hormone, cortisol is thought to “turn off” our ability to fight bacteria and viruses.

“Cortisol has a powerful effect on the immune system,” Professor Angela Clow, from the University of Westminster, said.

“It inhibits ‘nighttime immunity’, which is when immune cells gobble up bacteria and even ward off cancer progression.”

This differs from daytime immunity, which protects against more immediate risks, she added.

Scientists from Ohio State University first identified a link between stress and immunity when they analysed the healing time of puncture wounds in dementia caregivers.

Looking after someone with dementia forces a carer to contend with “loss of memory, inappropriate emotions, and wandering and restless behaviour of their loved ones”, they wrote.

Compared to “controls”, the caregivers’ wounds took 24% longer to heal, “providing evidence chronic stress can delay repair”.

(Getty Images)
Stress can inhibit nighttime immunity. (Getty Images)

How to combat stress

While our lives may feel hectic at times, stress does not have to be inevitable. If you're feeling frazzled, the first step to feeling better, according to the NHS, is to identify the cause.

The most unhelpful thing you can do is turn to something unhealthy to help you cope, such as smoking or drinking.

"In life, there's always a solution to a problem," Professor Cary Cooper, an occupational health expert at the University of Lancaster writes for the NHS. "Not taking control of the situation and doing nothing will only make your problems worse."

He says the keys to good stress management are building emotional strength, being in control of your situation, having a good social network, and adopting a positive outlook.

Other stress-reducing tips include trying to stay active.

While exercise won't make your stress disappear, the NHS says it can help to reduce some of the emotional intensity that you're feeling, clearing your thoughts and letting you deal with your problems more calmly.

The NHS also recommends mindfulness to help stress sufferers feel more in control.

“Mindfulness is the act of giving more attention to your thoughts and feelings in the present, as well as to the environment around you,” Dr Daniel Atkinson, clinical lead at, told Yahoo UK.

“It helps to interrupt the ‘autopilot’ mode that’s very easy to inhabit on a daily basis.

“And the increased awareness that’s given to our thoughts and feelings can better equip us to notice signs of stress developing.”

Confiding in a loved one may also make your problems feel more manageable. You could also contact Samaritans, call: 116 123 or email: if you need someone to talk to

Additional reporting SWNS.

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