Can you health 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 at this time 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?

Nicely, I’ve turn out to be 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 incredible job preventing viruses and different nasties. If I collected all of the air I breathed out over the course of a minute it will include 100 to 10,000 micro organism, 25,000 viruses and a single fungi, in keeping with Prof John Tregoning, immunologist at Imperial School London.

“You are respiration this stuff 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 might be 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 hearth on my pores and skin and all my mind can consider is making it to the pontoon while not 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 might produce antibodies or assault contaminated tissue – transfer out of their regular properties and head out on patrol considering there may very well be an an infection. So does this imply I am extra protected?

“Inside a number of hours that every 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 won’t be the proof for chilly water, however common train could properly do the trick.

On common adults get two to 3 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 medical trials, however the knowledge we now have is “all pointing within the path of it being good for you… however not a miracle remedy,” in keeping with Dr McCartney.

Laboratory research have advised common train could 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 advised they’d the immune methods of individuals a long time youthful.

“I do know the trials have not likely been performed in excessive sufficient high quality, however I will be doing plenty 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 type.

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

Nonetheless, the proof round vitamin D is hotly debated slightly 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 direction of doable advantages for individuals who’ve obtained respiratory illness and who’re very low in vitamin D,” says Dr McCartney, however there may be “inadequate” proof that it will assist everybody.

And whilst you’re considering what you may put within the procuring trolley, the jury remains to be out on whether or not prebiotics and probiotics that change the great micro organism in your intestine additionally profit immunity.

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

She additionally says echinacea, turmeric and ginger pictures are usually not going to present you an immune enhance.

Your immune system’s talents are usually not mounted all through the day.

“Our immune system is handiest 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.

Because of this your chilly typically 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 if you’re vaccinated, or uncovered to somebody coughing, within the morning.

Because the immune system does have this 24-hour cycle, then having “a daily every day rhythm” slightly than a mixture of late nights and lengthy lie-ins on the weekend “could properly assist enhance your immune system”, says Prof Riley.

Whereas we’re considering of boosting our immune system we must also bear 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 straight damages the lungs so they’re a much less efficient barrier to viruses.

“For those who 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 standard a part of how the physique reacts to an an infection.

However “uncontrolled irritation is unhealthy for you” because it disrupts the immune system “so chances are you’ll reply much less properly”.

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 will be tough for individuals to cease or to reverse, however they’re most likely probably the most modifiable ones,” says Dr McCartney.

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

But, cortisol dampens the immune system which can go away you extra liable to an infection.

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

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

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

You will 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 might use it as much as six instances a day at any time when they felt they have been coming down with one thing.

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

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 standard saline spray.

In case you are already doing all the same old issues to take care of your well being – not smoking, consuming healthily, exercising frequently – 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 standard, wholesome individual? There’s simply no actual proof which you could,” she says.

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

And possibly as an alternative of spending your cash on the most recent immune-boosting craze, she suggests fascinated about 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.