StemCell Therapy

Your immune system stands between you and deadly infections. But as you get older so does your immune age, making you more susceptible to disease. Fortunately, we are discovering plenty of things you can do to turn back the clock and stay healthy. In this episode of our video series Science with Sam, find out how your immune system works and how you can give it a boost.

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One of the most important things standing between you and a deadly infection is your immune system the intricate, biological defence mechanism that protects your body from harmful invaders. And theres a lot we can do to give our immune system a helping hand.

Your immune system is made up of two divisions: the innate immune system and the adaptive immune system, each with its own battalion of specialist cells and defensive weapons.

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The innate immune system is the first line of defence. Its made up of cells like the scary-sounding macrophage, and the less scary-sounding neutrophil. These general-purpose guards patrol the bloodstream on the lookout for anything that shouldnt be there. When they detect an intruder, they neutralise the threat by engulfing it like Pac-Man, spraying it with deadly chemicals or suicidally expelling their DNA and throwing it around the invader like a net.

Then theres the adaptive immune system, which you can think of as the immune systems special forces, elite agents trained to fight specific pathogens. Unlike the innate system, which can attack any invading cell or virus, these cells are only effective against one enemy, and they must be trained to fight them first.

B cells fight bacteria and viruses by making Y-shaped proteins called antibodies that neutralise an invader or tag it for attack by other parts of the immune system.

Then there are T cells. These coordinate and carry out attacks on infected cells. Helper T Cells call in reinforcements by sending out chemical messages known as cytokines. Killer T-Cells are the front line soldiers, trained, as the name suggests, to destroy the enemy.

When we encounter a disease for the first time, it takes a while for the adaptive immune system to learn how to fight it. But once its up and running, it creates a memory, allowing a fast and brutal response to future infections often neutralising it before you even notice. This is the premise of vaccines and the reason why you only get diseases like chicken pox once.

If you want to know more about vaccines, theres a video all about them, just hit the link at the end of this video. Better yet, subscribe to New Scientist today and get 20 per cent off if you enter the code SAM20 at checkout.

Your immune system works so well that, most of the time, you wont even notice it. But it weakens as you get older, making you more susceptible to infection. Thats a key reason why people over the age of 70 are most vulnerable to diseases like covid-19, or even the flu.

This decline happens to all of us, but it can be accelerated by lifestyle factors like smoking and inactivity. Obesity is also linked to a faster decline in immune potency.

All of which means that, although the strength of your immune system is linked to your age, a 40-year-old can have the immune system of a 60-year-old. Or on the flipside, a healthy 60-year-old may have the immune system of a 40-year-old.

Scientists have recently developed ways to measure your immune age. Fortunately, it turns out your immune age can go down as well as up. And there are some simple ways to turn back the clock on your immune system.

As we get older, some of our immune cells start to misbehave. Take neutrophils, those early responder cells. As they age, they get worse at hunting down intruders, blundering through your tissues, causing damage.

The root of the problem is an overactive enzyme involved in their sense of direction. Dialling down that enzyme rejuvenates the neutrophils so they know where theyre going. And theres a simple, drug-free way to do it: exercise.

One study in older adults showed that those who got 10,000 steps a day on average had neutrophils as good as a young adult.

Exercise also has benefits for your T cells. Before they are released onto active duty, T-cells mature in a little-known organ called the thymus gland in your chest. The thymus degenerates over time, resulting in a drop-off in the number of T cells.

Physical activity has a huge effect on the rate of this degeneration. A study found that amateur cyclists aged between 55 and 79 had youthful thymus glands and their T-cell counts were similar to those of much younger people.

Another key factor in your immune age is your gut bacteria. There is good evidence that poor gut health is a cause of premature ageing and that a healthy microbiome can reduce your immune age. Eating a healthy, varied diet rich in fibre, plant matter and fermented foods can help maintain a healthy community of gut microbes.

Your body has a highly evolved, intricate defence system thats effective at keeping you well, but only if you look after it.

I dont know about you but Ive been a bit less active of late, so Im considering this something of a wake-up call.

Looking after your immune system is a no-brainer, and its as easy as a walk in the park.

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Read more:
The immune system: How to boost it and lower your immune age - New Scientist News

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