Updated 06 September 2019

7 surprising things that can hurt your immune system

If you managed to survive the winter without getting the flu, your immunity is on track. But beware – there are some things that might hurt your immune system without you realising it.

It’s August and we are pushing towards spring. You’ve managed to avoid the flu – that is until the morning you woke up with that tell-tale scratchy throat. You’ve been so good about washing your hands and eating foods that boost your immune system. So, what went wrong?

Our immune system is made up of many different components, and it does its best to fight off the germs and bacteria we're exposed to on a daily basis.

While it’s possible to optimise your immune system by incorporating habits such as good nutrition and enough sleep, there are a number of unexpected factors that can compromise your immune system, no matter how hard you try to stay healthy.

1. Too much exercise

But isn’t exercise meant to strengthen your immune system? Certainly, yes, but strenuous exercise can take its toll on your body and immune system. When you are training for an endurance event such as a marathon, your body takes strain as it constantly has to recover from long hours on the road and in the gym. A study also showed that "extreme" runners were more prone to respiratory and secondary infections from the flu virus.

But you don’t have to be a top athlete to compromise your immune system – even frequent visits to the gym can increase your chance of catching a bug through touching things such like exercise bikes and treadmill handles. Always wipe the equipment before using it. And no matter how much you enjoy your exercise, listen to your body and give yourself time to recover between hard sessions.

2. Loneliness and isolation

This might be the time of year when work is especially demanding. You rush between the office and your house and you barely go out or make time for friends. But, even though you might be avoiding some germs, loneliness and the lack of a social life can actually wreak havoc on your immune system. Loneliness can increase cortisol, your body’s stress hormone, which can affect your immune system.

3. Ultraviolet radiation

While some sunlight and fresh air can do wonders for the body, overexposure to UV rays can affect your immune system. There are different UV rays – we all know about the natural UVA and UVB rays we get from sunlight, but there are also man-made rays emanating from the screens of computers and mobile phones.

According to the World Health Organization, there is evidence that exposure to UV levels can alter the activity and distribution of some of your immune system cells. 

Be smart about the sun – protect yourself by wearing a good-quality, high SPF sunscreen, and a hat and sunglasses outside. Limit your UV exposure indoors by changing your screen settings to eliminate blue light exposure, and take regular screen breaks. It is especially important to avoid blue light before you go to bed.

4. A pessimistic outlook on life

Working hard, eating healthy, exercising and hitting the sack early can unfortunately be of little value when you are taking life too seriously, research suggests. To counteract the many stressors in our daily lives, it’s important to find joy in the simple things, as a healthy outlook will help keep your immune system in shape.

5. Second-hand smoke

If you don’t smoke, or you recently managed to quit, it’s good. But unfortunately, mingling with friends and family members who smoke around you can damage your immune system. Research has shown that exposure to second-hand smoke (SHS) kills an estimated 600 000 people each year and increases one's risk of acute respiratory infections and chronic obstructive pulmonary disease (COPD). The immune system is also impacted, but exactly how that works remains a mystery.

6. Regular doses of antibiotics

Running to the doctor and insisting on antibiotics for the slightest infection can compromise even the healthiest immune system. A recent study conducted by researchers at Harvard, MIT, the Wyss Institute for Biologically Inspired Engineering and the Broad Institute, found that antibiotics can actually work against the body and impair the way the immune system wards of germs.

7. Touching the most mundane objects

You might be keeping your phone and your desk at work religiously clean, but there are many other things that you touch daily that may be full of germs. The shopping cart, the staircase, and even someone else’s pen. So, what can you do? Stock up on antibacterial hand sanitiser and wet wipes, and keep your own pen in your bag or briefcase.

Image credit: iStock


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