There are things that women can do, and men can't.
There are things that men can do, and women can't.

But, why does this matter?

Because survival matters to us all.
A short thread on survival.

1/5 X Chromsome and Y chromosome
Men on average have more muscle mass, greater height, overall size, and physical strength, when compared with their genetic female counterparts.

It's the fundamental reason why in competitive sports such as the olympics, men outperform women by up to 20% or more.

Another physical difference between M+F becomes apparent with morbid mathematical certainty, every time famine strikes.

The Irish Potato Famine/Holodomor killed millions, yet more men succumbed to starvation than women.

Why did many more women survive?


On average women have up to 40% more fat on their bodies than a similarly dimensioned man (height + weight). That means that women have more stored energy available to them in the form of fat.

Because in lean times, fat means the difference between survival and death.

Each sex is biologically unique.

Men are biologically built for physical strength.

And women are biologically built for survival. Because the survival of women means the survival of us all.



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More from @sharonmoalem

12 Jan
Why is the 'Gender Data Gap' in medicine dangerous?

Because the real data gap in medicine pertains to sex (M+F). So why are activists using 'gender', when the correct word in this case is 'sex'?

Sex is not gender.
A short thread on the importance of sex in medicine.

Right now the conflation in science between the words sex/gender has become so widespread that both words have lost their original meaning.

In describing the dimorphic immune response to viral infections like #COVID19, is it sex or gender?

When we speak about the mammalian female survival advantage that results in women outliving men everywhere around the world regardless of circumstances, isn't this sex?

For some institutions, apparently not.

Read 5 tweets
11 Jan
Biological sex in mammals is binary (M/F). With all our advancements in genetics/medicine we currently have no way to change an individual's biological sex.

So why does this matter?
Because Medicine.

So, let's talk about sex.

A short thread.

Examples of Differences in Sex Development (DSD) or Intersex actually help us to better understand the two separate pathways of developmental trajectories of sex in mammals.

As individuals with intersex have expressed often, 'we're not a 3rd sex, we're female or male'.

As I wrote about in #TheBetterHalf, we continue to harm both sexes by ignoring the fundamental biological differences between them.

As twice as many males have unfortunately died from #COVID19 and twice the number of females have long-COVID.…

Read 5 tweets
9 Jan
Why do bartenders have the most experience dealing with the differences in how women and men metabolize a drug?

Because alcohol.

A short thread on how medicine doesn't consider drug metabolism differences between the biological sexes.

1/5 Image
We used to think that differences in alcohol tolerance between M + F was only due to any differences in weight/fat.

But that's not the whole story.

Even when sexes are matched for weight, there is a marked discrepancy in which sex metabolizes alcohol faster, M>F.

2/5 Image
Women don't have the same level of activity of alcohol dehydrogenase, an enzyme which helps break down alcohol in the body.

And other enzymes that break down prescription drugs may also be less active in women, making them more likely to experience adverse side effects. Image
Read 7 tweets
8 Jan
Turns out that getting chemo is like sending cancer to a relaxing spa getaway for the weekend, so that it comes back refreshed and ready to kill.

That's disturbing.

What else have we misunderstood?

Biological sex and cancer.

A short thread.

Almost every type of cancer affects men more than women. And overall, more women survive a cancer diagnosis. Men also develop about 150,000 extra cancers per year in the US, compared to women.

Why is that?

Because biology.

We used to think that the reason for female cancer 'resistance' was behaviorally based because: women see their doctor more often and drink less alcohol etc.

But that's not the whole story.

Read 7 tweets
1 Jan
Why are 95% of 'supercentenarians' (those who are 110 years of age and beyond) women?

Because biological sex.

And so, a short thread on sex and longevity.

1/7 Image
From the beginning of life more girls make it their first birthday almost everywhere around the world, according to the @WHO. Girls have lower rates of prematurity and fewer complications after birth.

Females don't wait long to begin to dominate when it comes to survival.

2/7 Image
Women are naturally resistant to cancer.

Throughout life, women not only develop less cancers in organs and tissues that they share with men, but even when they do, they're much more likely to survive them.

Note: this is the case even when we adjust for behavior.

3/7 Image
Read 8 tweets
21 Dec 20
The evolutionary arms race will never really end between microbes and humans. They (microbes) have as much to lose as we do if it does.
Microbes are responsible for some of the most profound differences between humans which we can still observe even today. This has been true since the first human.
Some humans are born able to naturally resist HIV. This is thanks to them inheriting a small but significant genetic change - CCR5 delta 32.

Most humans do not have CCR5 delta 32.

HIV takes advantage of this fact.
Read 6 tweets

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