We all know healthy habits are good for us – but what about
the lifestyle factors that could be damaging our defences? Liz Connor
learns more.

We’re often told about ways to help strengthen our immune systems – but
what about the things that might be doing it no favours at all?

Just as healthy lifestyle habits can play a key role in supporting our
immune system, there may be certain things we’re doing that possibly
hinder it too – no matter how many oranges you’ve got piled up in your
fruit bowl.

Here’s seven things that could be negatively impacting your immune

  1. Too many late nights

Sleep might not come as easily during anxious times like right now. In
fact, the hashtag #cantsleep has recently been trending, as people share
their frustrations with their off-kilter sleeping patterns.

Getting enough sleep not only feels great but it’s also an essential
function for the body, explains Dr Emer MacSweeney, medical director at
Re:Cognition Health ( “As well as helping to
maintain a healthy brain function, physical health, executive function
and emotional wellbeing, it promotes a healthy immune system too,” says
MacSweeney. “It’s all down to cytokines – a type of protein which is
made and released during sleep. Cytokines target infection and
inflammation in the body and create an immune response – so without
sufficient sleep, our body produces fewer of these essential proteins,
which can result in weaker immunity.”

She recommends aiming for seven to nine hours of quality sleep each
night and adds that naps are also a great way to top up, particularly if
you’re struggling with a bout of insomnia during lockdown.

  1. Smoking

The health risks of smoking have long been documented, and cigarettes
can harm your immune system, as well as increasing your risk of
developing respiratory illnesses and other major diseases, including
many cancers and heart disease. “The nicotine in cigarettes increases
cortisol levels, reduces cell antibody formation and damages the lungs,
which makes them more susceptible to infection,” explains MacSweeney.

If you do smoke, why not try to use the lockdown period as a prompt to
cut down or quit entirely? Stopping smoking isn’t easy but there’s lots
of support and online resources to help – and the rewards will be so
worth it.

  1. Not getting enough vitamin D

As well as strong bones and healthy blood cells, vitamin D is really
important for keeping your immune system in good nick.

“We can only make vitamin D in our skin on exposure to sunlight when the
UV index is greater than three,” explains Dr Sarah Brewer, medical
director at Healthspan ( “As a result, vitamin D
deficiency is increasingly likely during autumn and winter in the UK, as
there isn’t enough sun for us to produce enough of it.”

Even in springtime though, many people still fail to make enough vitamin
D (and remember – it’s always important to protect your skin from sun
damage). Lockdown means many of us are spending more time indoors than
usual too, so our vitamin D levels might be even lower.

“Vitamin D helps to activate macrophages – our hunter-killer immune
cells that engulf and destroy viruses and bacteria, and stimulates the
production of antibiotic-like proteins (defensins) within the lining of
the respiratory tract,” explains Brewer. “In fact, our immune cells,
including B and T lymphocytes, all carry specific vitamin D receptors
that help to regulate their activity.”

As vitamin D deficiency is fairly widespread, Brewer recommends taking a
daily supplement. Try Healthspan Super Strength Vitamin D3 Spray (£5.95
for 100 daily doses,

  1. Not looking after your gut bacteria

As well as promoting digestion, ‘friendly’, lactic acid-producing
bacteria in the lower part of the gut can help stimulate our resistance
to infection – including viruses that may cause upper respiratory tract

“Research involving 3720 adults and children concluded that, compared
with a placebo, taking a probiotic supplement can reduce the chance of
experiencing at least one to three acute upper respiratory tract
infections by 47%,” says Brewer. “It also shortened the length of a
cold, reduced antibiotic prescription rates and meant children took less
time off school.”

Gut-boosting supplements are not all created equally though. Plus, it’s
important to remember that your actual diet – the food you eat – is the
most crucial factor, and a varied, balanced diet with plenty of fibre is
essential for promoting healthy gut bacteria.

If you do want to consider a supplement too, Brewer advises: “When
selecting a supplement, look for those that provide a known quantity of
digestive bacteria, such as 10 billion to 50 billion colony forming
units (CFU) per dose, and which provide at least three different strains
for optimum benefit.”

Try Vita Bright’s Bio Cultures Advanced Multi Strain Complex (£15.99 for
60 capsules,

  1. Not exercising enough

Regular movement is a key component of a healthy lifestyle. The NHS
recommends everyone should do a minimum of 150 minutes a week of
moderate-intensity aerobic exercise per week. Being fit and regularly
physically active supports out health overall – including immune

“Exercise can help promote sleep and reduces the stress hormone
cortisol, which can impair the functioning of cells that fight
infection,” notes MacSweeney. “It also improves metabolic health, has
anti-inflammatory influence on the body and helps delay the onset of

If you don’t fancy the idea of gruelling bootcamp workouts, MacSweeney
suggests dancing as an ideal way to keep active. Not only is it a
heart-healthy cardio burn, but learning new routines is also an active
workout for the brain.

  1. Drinking too much

When you’re feeling tired or anxious, it can be tempting to crack open a
bottle of wine to soothe your worries, but MacSweeney warns that alcohol
can weaken the immune system and make the body more susceptible to

“Drinking in excess impairs [the] ciliary function of the lungs, which
works to keep the airways clear of dirt and irritation,” she says.

“It also reduces the immune system’s response to bad bacteria,
increasing the risk of infection.” she adds – which is why heavy
drinkers might notice they catch colds and other illnesses more.

If you do want to enjoy a drink, stick to the intake guidelines.

  1. Loneliness

Studies have also found that people who are lonely or isolated may have
less healthy immune function than those who feel more socially

There might be a number of factors associated with exactly how
loneliness and isolation impact our health. However, MacSweeney also
notes: “The increased anxiety associated with loneliness can be
detrimental to the immune system. This is why it’s important to keep
socially active, even during lockdown.”

If you live alone, stay in touch with friends, loved ones and colleagues
through video chats, phone calls and messages. “Virtual group gatherings
through apps such as Zoom can also be arranged,” she adds. “It’s a great
way to stay connected with friends and family throughout the challenging
times we are currently living in.”