Is this proof man flu is REAL and males are the weaker intercourse?

Men beware — we’re getting into peak man flu season, when annual UK charges of colds and flu are at their highest.

And so are the standard household jibes about males who take to their beds complaining of debilitating signs whereas equally affected girls soldier on with work, chores and childcare.

The time period ‘man flu’ even has its personal entry within the Oxford English Dictionary, as ‘a chilly or comparable minor sickness that anyone, often a person, catches and treats as if it had been flu or one thing extra critical’.

However, behind all of the gendered joshing there’s a critical facet to man flu, which may additionally clarify why most cancers charges are considerably greater in males whereas painful autoimmune illnesses — equivalent to rheumatoid arthritis — are extra frequent in females.

It might even clarify why the Covid-19 pandemic killed many extra males than girls. Data from the Office for National Statistics present that within the opening months of the pandemic in 2020, males in England and Wales had been dying of coronavirus at twice the speed of girls.

For many years, scientists have debated whether or not man flu is actual or not.

In a brand new guide, How To Stay Healthy, nutritionist Jenna Hope argues ‘the proof exhibits the feminine immune system is stronger than the male immune system’, and suggests it is right down to hormones — the feminine intercourse hormones progesterone and oestrogen are inclined to help the immune system, whereas the male hormone testosterone can suppress immunity.

In reality the position of oestrogen in feminine immunity was highlighted by immunologists at Johns Hopkins University in Baltimore, Maryland, in 2016.

They contaminated cells from males’s and girls’s nostril linings with a standard flu virus (seasonal influenza A), earlier than including the commonest type of oestrogen in girls, known as oestradiol, to all of the cell cultures.

In the ladies’s cell cultures, the oestrogen resulted in a big drop in ranges of the flu virus. But the virus ranges within the males’s cell cultures remained unchanged, reported the American Journal of Physiology-Lung Cellular and Molecular Physiology.

Both sexes produce oestradiol: males make a tiny quantity of their testes (probably to assist sperm manufacturing) whereas girls launch massive quantities from their ovaries, primarily to construct and preserve their reproductive system.

By distinction testosterone, the principle male hormone, seems to suppress immune defences, in all probability as a result of it drives actions, equivalent to constructing muscle mass which demand vitality.

For instance, a research by immunologists at Stanford University in California, printed in 2014, discovered that males with higher-than-average ranges of testosterone had decrease ranges of antibody response when given jabs.

In evolutionary phrases, researchers surmised, decreased immunity was much less essential for males than trying highly effective and fathering shortly; males usually tend to die in fights or accidents earlier than an an infection kills them.

A research earlier this yr discovered having a poor evening’s sleep significantly diminished the quantity of safety conferred by a vaccine the subsequent day — however solely in males.

The analysis, printed within the journal Current Biology, analysed earlier research involving over 500 women and men and confirmed that males who slept for fewer than six hours the evening earlier than receiving a vaccination towards flu or hepatitis had far fewer antibodies than those that slept for seven hours or extra.

The internet impact was to knock two months off the time a person was protected by the jab. Yet there was no such loss in girls who had little sleep earlier than a jab.

But why would girls have stronger immune methods than males?

From an evolutionary perspective, having a powerful immune system permits girls to greatest shield the foetus from infections being handed from them to the child within the womb, says Francisco Úbeda de Torres, a professor of mathematical biology who research evolution and well being at Royal Holloway, University of London. This course of is known as ‘vertical transmission’.

As Professor Úbeda de Torres explains: ‘When pregnant girls contract infections from individuals round them, they’ll transmit them to their offspring within the womb via the placenta.

‘Evolutionary pressures have meant girls and their infants survive greatest if the moms’ our bodies mount a powerful immune response to pathogens, to guard the offspring as successfully as potential.’

But girls can generally pay a painful worth for this potential to guard their unborn younger on this approach, he says.

‘All the proof signifies that this comes at a value when it comes to a lot greater incidence of autoimmune illness.’ Autoimmune illnesses equivalent to rheumatoid arthritis, kind 1 diabetes and psoriasis happen when the immune system overreacts and assaults wholesome tissues.

Research means that round 80 per cent of sufferers with autoimmune illnesses are girls (however extra on this later).

Men, in the meantime, pays a heavy worth for operating weaker immune responses, provides Professor Úbeda de Torres — and this could go far past man flu.

‘Men produce a weaker response and are at considerably greater threat of growing many cancers in comparison with girls,’ he says.

‘This is as a result of a weaker immune response means pathogens are capable of infect males for longer — giving viruses or micro organism extra time to tamper with the genetics of the cells they infect.

‘One of the issues these pathogens can do is make the contaminated cells proliferate.

‘This helps infections to unfold via males’s our bodies, nevertheless it additionally will increase the danger of cells quickly replicating uncontrolled and turning into most cancers.’

That weaker response took a tragic toll amongst males in the course of the Covid-19 pandemic, based on an evaluation of knowledge launched by the King’s Fund final yr. In 2019, life expectancy at delivery in England stood at 79.9 years for males and 83.6 years for girls — a distinction of three.7 years.

However, as a result of Covid killed considerably extra males than girls, in 2020 and 2021 the gender hole widened to 4 years —with males’s life expectancy falling to 78.6 years in comparison with 82.6 years for girls.

When it involves mounting stronger immune responses to infections, rising analysis suggests that girls have one other secret weapon, which is hid of their chromosomes.

As Tim Vyse, a professor of molecular medication at King’s College London, explains: ‘In phrases of human chromosomes, girls are XX and males are XY — however you solely want one X chromosome to manage the immune system. So when females are within the womb the affect of one of many Xs is basically shut down.’

However, this shutting down course of isn’t as neat and tidy as beforehand thought, provides Professor Vyse. ‘Some of the affect of the additional suppressed chromosome nonetheless comes via — which we name ‘X evasion’.

‘We assume this X evasion might confer some evolutionary benefit with stronger immune defences however may additionally drive greater ranges of autoimmune illness in girls.’ (In different phrases, their strong immune system can go into overdrive and extra simply set off an assault on their very own tissues.) A gene known as UTX might play a key position: this gene is situated on the X chromosome, so due to this fact girls — with their two Xs — have yet another copy of UTX than males.

In a 2023 research within the journal Nature Immunology, researchers on the University of California, Los Angeles discovered that the UTX gene — and the protein it successfully ‘produces’ — are essential for regulating the operate of pure killer (NK) cells.

NK cells are a part of our immune system — they kill cells contaminated by viruses and rogue most cancers cells.

The research means that as a result of females have double the UTX gene, they’ve extra of the UTX protein of their pure killer cells — experiments the scientists carried out indicated {that a} double dose of UTX boosts the NK cells’ anti-viral operate — which means girls are higher ready than males to guard themselves towards viruses. Professor Vyse’s personal analysis has proven how this strengthened defence generally is a double-edged sword.

‘We have discovered that girls with the autoimmune dysfunction lupus [a long-term condition that causes joint pain, skin rashes and tiredness] had higher Covid-19 outcomes than girls who didn’t have lupus. This suggests there is a steadiness available between autoimmune illness threat and an infection threat.’

Why ought to this be?

Professor Vyse has an evolution-based rationalization: ‘It could also be that biology desires females to outlive infectious outbreaks extra.

‘You can lose 50 per cent of the males from a human inhabitants and it will not actually matter, the inhabitants will compensate and the inhabitants will survive.

‘However, a human inhabitants would almost certainly be devastated if it loses 50 per cent of its fertile breeding females.’

But whereas males, in evolutionary phrases not less than, seem relatively dispensable, research present they’re additionally much less prone to take preventive care or search care when unwell.

So possibly it is time the weaker intercourse sorted itself way more fastidiously.

 Doctor TikTook – Experts assess viral well being developments

This week: The 30-gallon water problem 

WHAT SOCIAL MEDIA SAYS: The hashtag #30gallonchallenge has greater than 25 million views on TikTook, with individuals selling ingesting a gallon — roughly 4.5 litres — of water each day for 30 days. Devotees declare it helps to ‘flush out toxins’ and makes their pores and skin glow.

THE EXPERT’S VERDICT: ‘While water is important for all times, an excessive amount of is a nasty factor, resulting in what’s often called hyponatraemia, the place our blood salt ranges develop into dangerously low,’ says dietitian Dr Carrie Ruxton. In reality, extreme quantities could be deadly.

‘Anyone who remembers the ecstasy-related deaths of the Nineties, typically brought on by extra consumption of water beneath the affect of the drug, will probably be appalled by this problem. It causes physique cells to swell up, together with these within the mind which may result in headache, hassle respiration and even mind harm.

‘There is not any must drink gallons of water, significantly as everybody has an in-built detoxifier — it is known as the liver.

‘As a information, a fluid consumption of round six to eight glasses a day is adequate for most individuals. Drink two to 3 glasses extra and embrace an electrolyte pill for those who’re participating in strenuous sport or if the climate is scorching. Tap water, milk, tea, espresso, fruit juice and diluted squashes all rely in direction of this goal.’