Are you able to well being hack your immune system?

It’s a chilly morning within the depths of winter.

And I really feel like I’ve left my sanity in addition to my heat garments within the altering room as I stride out to the sting of a reservoir in my swim shorts.

A brightly-coloured chalk signal informs me that the water temperature right now is a cold 3.9C, as one of many regulars tells me this isn’t chilly water swimming, it is “ice” water swimming.

How did I find yourself right here?

Effectively, I’ve change into enthralled by the concept of enhancing or boosting the immune system. My physique has been the dwelling embodiment of the “quademic” that the NHS spent all winter warning us about. It has been a relentless stream of colds and coughs and one explosive tummy.

Our immune methods already do a improbable job combating viruses and different nasties. If I collected all of the air I breathed out over the course of a minute it might include 100 to 10,000 micro organism, 25,000 viruses and a single fungi, in line with Prof John Tregoning, immunologist at Imperial School London.

“You are respiratory these items in on a regular basis, there’s only a swirling mass of pathogens [organisms that cause disease] within the air,” he says.

However there’s loads of meals, dietary supplements and actions which are touted for his or her “immune-boosting” properties. Can we dial up our safety?

And that is why I discover myself wading out and pushing off for a chilling blast of breaststroke.

The icy water is like fireplace on my pores and skin and all my mind can consider is making it to the pontoon without having assist from the lifeguards.

However research have proven the adrenaline hit of the chilly water does flood the blood stream with infection-fighting cells.

White blood cells – which may produce antibodies or assault contaminated tissue – transfer out of their regular houses and head out on patrol pondering there may very well be an an infection. So does this imply I am extra protected?

“Inside a couple of hours that each one goes again to regular,” says Prof Eleanor Riley, an immunologist on the College of Edinburgh.

“There isn’t a proof that individuals who go chilly water swimming have fewer colds or fewer infections.”

There may not be the proof for chilly water, however common train might effectively do the trick.

On common adults get two to a few colds per yr and kids between 5 and eight, says Dr Margaret McCartney, a GP and skilled in evidence-based drugs, on the College of St Andrews.

“[But] individuals who do reasonable quantities of train are inclined to report fewer viral infections,” she says.

There’s a lack of conclusive scientific trials, however the knowledge now we have is “all pointing within the route of it being good for you… however not a miracle remedy,” in line with Dr McCartney.

Laboratory research have steered common train might sluggish the ageing of the immune system. Your physique’s defences are in decline from our 20s onwards, however analysis on 80-year-old cyclists steered they’d the immune methods of individuals many years youthful.

“I do know the trials have probably not been finished in excessive sufficient high quality, however I will be doing loads of biking,” she says.

The very first thing that springs to my thoughts is vitamin C – both by devouring a mountain of oranges or in tablet kind.

“It is a no from me,” says Dr McCartney. Being poor might impair the immune system, however for the overwhelming majority there may be little to be gained from having further. The identical goes for multivitamins, which says Dr McCartney simply make “costly urine”.

Nonetheless, the proof round vitamin D is hotly debated relatively than being a agency no. Vitamin D ranges dip in winter as it’s made when our pores and skin is uncovered to daylight.

“I believe the proof is pointing in the direction of doable advantages for individuals who’ve bought respiratory illness and who’re very low in vitamin D,” says Dr McCartney, however there may be “inadequate” proof that it might assist everybody.

And when you’re pondering what you would possibly put within the buying trolley, the jury continues to be out on whether or not prebiotics and probiotics that change the great micro organism in your intestine additionally profit immunity.

“I do imagine that may be a actually vital space of examine, however we’re missing the actual world knowledge that may allow you to suggest this,” says Dr McCartney.

She additionally says echinacea, turmeric and ginger photographs usually are not going to provide you an immune increase.

Your immune system’s skills usually are not fastened all through the day.

“Our immune system is best within the early morning at across the time we get up, continues to be extremely efficient by way of the early a part of the day after which afterward within the day it begins to wind down,” says Prof Riley.

This is the reason your chilly usually feels worse within the morning as your signs are the results of an immune system firing on all cylinders.

The decline kicks in “about 4 or 5 o’clock within the afternoon”, so that you may need higher safety in case you are vaccinated, or uncovered to somebody coughing, within the morning.

Because the immune system does have this 24-hour cycle, then having “a daily each day rhythm” relatively than a mixture of late nights and lengthy lie-ins on the weekend “might effectively assist increase your immune system”, says Prof Riley.

Whereas we’re pondering of boosting our immune system we must also keep in mind there are issues that truly enhance our vulnerability to an infection.

One of many large ones is smoking as a result of it instantly damages the lungs so they’re a much less efficient barrier to viruses.

“Should you think about the lungs like a sieve, smoking will break holes within the sieve, so extra can get by way of,” says Prof Tregoning.

It additionally dials up irritation all through the physique. Irritation is sort of a thermostat for the immune system and is a traditional a part of how the physique reacts to an an infection.

However “uncontrolled irritation is dangerous for you” because it disrupts the immune system “so you might reply much less effectively”.

Weight problems is one other issue that may enhance susceptibility to infections in addition to the severity by ramping up irritation within the physique.

“Each of these issues might be troublesome for individuals to cease or to reverse, however they’re most likely essentially the most modifiable ones,” says Dr McCartney.

Being continually careworn raises ranges of the hormone cortisol within the physique.

But, cortisol dampens the immune system which can depart you extra vulnerable to an infection.

Prof Tregoning says this can be the reason for why being in nature, going for a stroll, spending time with associates – even chilly water swimming – might have some useful impact.

“You are much less careworn, much less cortisol, so subsequently your immune system is fitter for the function it’s making an attempt to do,” he says.

Prof Riley provides: “There’s completely little doubt that being comfortable, being in a optimistic way of thinking, has a really, essential impact on our bodily features.”

You could have most likely seen merchandise within the store which you could spray up every of your nostrils on the first signal of a chilly.

A report within the Lancet confirmed they do work.

It gave 1000’s of individuals both a salt water (saline) spray or a gel-based one. They may use it as much as six occasions a day each time they felt they had been coming down with one thing.

Individuals who simply went about their each day lives with out a nasal spray spent a median of eight days being in poor health in the course of the examine.

However that fell to 6 days in these utilizing a both salt water (saline) or a branded gel-based spray.

Dr McCartney argues {that a} branded spray could be no higher than a traditional saline spray.

In case you are already doing all the standard issues to take care of your well being – not smoking, consuming healthily, exercising repeatedly – then your immune system is already within the “absolute best situation” to reply to an an infection, says Prof Riley.

“Are you able to do something to spice up above being a traditional, wholesome particular person? There’s simply no actual proof which you could,” she says.

“However there are issues you are able to do to enhance your immunity in opposition to explicit particular person infections and that’s to be vaccinated.”

And perhaps as an alternative of spending your cash on the newest immune-boosting craze, she suggests occupied with methods of not getting contaminated within the first place so “watch out who you socialise with”.

Inside Well being was produced by Hannah Robins and the programme airs on BBC Radio 4 on Tuesdays at 09:30 GMT and on BBC Sounds.