Last updated: 18th April 2023

What is your immune system and why should you improve it?

Your immune system comprises several biological processes that detect and protect again pathogens, like bacterial and viral infections, cancer cells, and foreign objects in the body such as splinters. 

Having a strong immune system helps your body to fight off illnesses. Unfortunately, many of our day to day habits can suppress or weaken the immune response, meaning you may get ill more frequently, or have stronger symptoms when you do get ill. 

We asked Dr. Sarah Hattam the best ways to support a healthy immune system. Dr. Sarah has 25 years' experience and is on a mission to fight the pseudo-science in the industry. She is passionate about sharing information that is backed by the latest science and research about how our human bodies and brains really thrive. This is what she had to say:

One of the best ways to prevent illness is to practice good hygiene, including washing your hands frequently, avoiding touching the face, mouth and eyes, and treat your mobile phone like a third hand, wiping it over with alcohol wipes regularly. Making sure food is prepped, cooked, and stored correctly can also help to eliminate bacteria that might cause illness.

There is no magic pill or solution to ‘boost’ your immune system, there are some simple steps you can take to help support your immune response - giving your immune system the best chance to fight off any pathogens that come your way. 

Lack of sleep is one of the main contributors that can reduce the effectiveness of your immune system.

Studies show that people who don't get quality sleep or enough sleep are more likely to get sick after being exposed to a virus [1].

Not enough sleep can also affect how quickly you recover if you do get sick, as our white blood cells (also known as the body's natural killer cells) become less effective when we are sleep deprived. But we understand that it's not quite as easy as just saying 'get more sleep'. Some simple tips to improve sleep quality are to ditch the devices before bed, avoid caffeine after mid-afternoon and remember to give yourself time to unwind from the day. A clear mind not only can help you drift off into dream land quicker, but also helps you reach the deep phase of sleep which is where the most restorative sleep happens.

Just like a healthy diet, exercise contributes to good health, and subsequently a healthy immune system.

Research shows that adults who are physically active are almost half as likely to succumb to minor infections in comparison to sedentary adults [2].

One reason for this is thought to be because exercise promotes good circulation. Good circulation allows immune cells to move through your bloodstream and do their job more efficiently, meaning more effective scanning and action to deal with disease-causing bugs.

Generally, a lot of emphasis is put on Vitamin A, C and E and their role in immune function. But it's important to not forget Vitamin D. Not only does it play an essential role in supporting healthy bones but has also been recognised as supporting our immune system. Specifically, the immune response to viral infections. However, unsurprisingly 29% of adults have insufficient levels of vitamin D in the winter months [3]. This so-called sunshine vitamin is only manufactured in our body when sunlight hits our skin, making it common for us to be under the recommended 10ug per day.

It's recommended that you include vitamin D rich food sources within your diet.

Foods such as oily fish, eggs and fortified cereals can help to increase vitamin D levels. But vitamin D supplements are also a good, cost-effective option which have even been shown to reduce respiratory infections and improve asthma control [4].

Easy for us to say, right?  21^st^ century life is full on; we're juggling competing demands and the incessant news chatter about the current pandemic isn't exactly helping the situation. But we know that persistent stress and the subsequent release of stress hormones in our blood stream can damp down our immune system's ability to respond effectively to infections [5].

Make sure you keep doing the things that bring you enjoy, and remember to take a mindful moment or two during a busy day.

All of these things allow our "tend and mend" system to be switched on which has many beneficial effects for health"

Lots of dietary supplements claim to have immune boosting properties. But what does the science actually say? The NHS website says that there is little evidence that supplements such as vitamin C, echinacea or garlic either prevent viral infections or speed up recovery. It's important to remember that most of us can meet our RDA nutrient needs with a varied, balanced diet. So, when it comes to supplements, you could be wasting your money if expensive products make extravagant claims. Remember, if something sounds too good to be true, it usually is!

Instead of going all out on supplements, make sure you are getting enough vitamins and minerals in your diet by eating an abundant variety of fresh fruit and vegetables. 

Eating a rainbow of different coloured fruit and veg will give your body a range of phytonutrients and micronutrients to improve its defences.

You'll also want to ensure a healthy balance of fats, protein, carbs, and fibre, too. Aim for 80% of your diet to come from complex carbs, lean meats (or vegetable based proteins) and veg to keep your immune system in top shape.

As we get older, our immune system becomes less effective at fighting off potentially harmful invaders. Allowing your digestive system to have a whole 12-hour break from food overnight can keep our digestive system healthy, allow cells to repair themselves and keep our immune system strong.

Studies show that alcohol weakens our immune system [6] and can also disrupt quality sleep and tends to drive us towards unhealthier food decisions. So, there are lots of reasons why it could be sensible to cut right back or even avoid it altogether. Smoking can also wreak havoc on your immune system and should be cut out. 

So, keep on making healthy lifestyle choices because they will help you to keep your immune system tip-top and aid your recovery if you do get sick.

Disclaimer: None of the above is intended to be medical advice. Please consult your GP as usual if you have ongoing medical conditions or take regular medication before making any significant changes.

If you've fallen ill and have caught a cold, you may be wondering if you can continue with your fitness regime - learn all about our advice for running with a cold here. 

If you're interested in supporting your immune system with exercise, find a PureGym near you and sign up for a membership today. With our top-of-the-range equipment and friendly Personal Trainers, you'll have everything you need to improve your fitness.

References:

1. Cohen, S., Doyle, W., Alpher, C., Deverts, D., & Turner, R. (2009) Sleep habits and susceptibility to the common cold. Archives of Internal Medicine, 169, (1) pp. 62 -- 67.
2. Shephard, R., Shek, P. & DiNubile, N. (1999) Exercise, immunity and susceptibility to infection. The Physician and Sports Medicine. 27, (6). pp. 47 -- 71.
3. National Diet and Nutrition Survey: Years 1 to 9 of the Rolling Programme (2008/2009 -- 2016/2017): Time trend and income analyses. Public Health England. Published January 2019
4. Ginde, A., Mansbach, J & Camargo, C. (2009) Vitamin D, respiratory infections, and asthma. Currently Allergy & Asthma Report. 9, (1). pp. 81 -- 87.
5. Cohen, S., Tyrrell, D. & Smith, A. (1991) Psychological stress and susceptibility to the common cold. The New England Journal of Medicine, 325, (9). pp. 606 -- 612.
6. Sarkar, D., Jung, K. & Wang, H. (2015) Alcohol and the immune system. Alcohol Research, 37, (2). pp. 153 -- 155.