
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 the moment 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 develop into enthralled by the concept of enhancing or boosting the immune system. My physique has been the residing 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 implausible job preventing viruses and different nasties. If I collected all of the air I breathed out over the course of a minute it might comprise 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 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 can be touted for his or her “immune-boosting” properties. Can we dial up our safety?
Can a chilly water swim cease you getting in poor health?

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 might produce antibodies or assault contaminated tissue – transfer out of their regular houses and head out on patrol pondering there could possibly be an an infection. So does this imply I am extra protected?
“Inside just a few hours that each one goes again to regular,” says Prof Eleanor Riley, an immunologist on the College of Edinburgh.
“There is no such thing as a proof that individuals who go chilly water swimming have fewer colds or fewer infections.”
Common train might provide you with a youthful immune system
There may not be the proof for chilly water, however common train might properly 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 medication, 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 course of it being good for you… however not a miracle remedy,” in line with Dr McCartney.
Laboratory research have recommended 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 recommended that they had the immune methods of individuals many years youthful.
“I do know the trials have probably not been carried out in excessive sufficient high quality, however I will be doing a variety of biking,” she says.
What about nutritional vitamins?

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’s 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 fairly 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 potential advantages for individuals who’ve received respiratory illness and who’re very low in vitamin D,” says Dr McCartney, however there’s “inadequate” proof that it might assist everybody.
And whilst you’re pondering what you may put within the procuring 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 could be a actually vital space of examine, however we’re missing the true world knowledge that will allow you to suggest this,” says Dr McCartney.
She additionally says echinacea, turmeric and ginger pictures usually are not going to offer you an immune enhance.
Keep watch over the clock?
Your immune system’s talents usually are not mounted 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 means of the early a part of the day after which afterward within the day it begins to wind down,” says Prof Riley.
For this reason 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 might 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 each day rhythm” fairly than a mixture of late nights and lengthy lie-ins on the weekend “might properly assist enhance your immune system”, says Prof Riley.
Cease damaging your immune defences!

Whereas we’re pondering of boosting our immune system we also needs to bear in mind there are issues that truly improve our vulnerability to an infection.
One of many large ones is smoking as a result of it immediately damages the lungs so they’re a much less efficient barrier to viruses.
“In case you think about the lungs like a sieve, smoking will break holes within the sieve, so extra can get by means 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 improve 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 in all probability essentially the most modifiable ones,” says Dr McCartney.
Destress in the event you can

Being consistently pressured raises ranges of the hormone cortisol within the physique.
But, cortisol dampens the immune system which can go away you extra susceptible 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 helpful impact.
“You are much less pressured, much less cortisol, so due to this fact your immune system is healthier for the function it’s making an attempt to do,” he says.
Prof Riley provides: “There may be completely little question that being joyful, being in a optimistic way of thinking, has a really, crucial impact on our bodily features.”
Squirt some salty water up your nostril
You may have in all probability seen merchandise within the store that you may spray up every of your nostrils on the first signal of a chilly.
A report within the Lancet confirmed they do work.
It gave hundreds of individuals both a salt water (saline) spray or a gel-based one. They may use it as much as six instances a day each time they felt they have 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 can be no higher than a standard saline spray.
So can the immune system actually be boosted?
If you’re already doing all the standard issues to take care of your well being – not smoking, consuming healthily, exercising usually – then your immune system is already within the “very 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 particular person? There’s simply no actual proof that you may,” she says.
“However there are issues you are able to do to enhance your immunity in opposition to specific particular person infections and that’s to be vaccinated.”
And possibly as an alternative of spending your cash on the newest immune-boosting craze, she suggests excited 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 RAYNAE Radio 4 on Tuesdays at 09:30 GMT and on RAYNAE Sounds.