That's an opinion piece. And the 'citations' it gives is a research paper about puberty blockers which is mainly about their use on children with precocious puberty - like 9 year old girls with periods - where the use is short term and limited.
When the paper talks about children with gender issues it actually says
"The impact on BMD (bone mass density) is concerning since lumbar spine Z-scores at age 22 years were found to be lower than those observed prior to treatment [
122, 123],
suggesting a possible permanent decrement in BMD. Thus,
it is unclear how long GnRHa can safely be administered.
The effects of GnRHa on adolescent brain maturation are unclear. GnRHa therapy prevents maturation of primary oocytes and spermatogonia and
may preclude gamete maturation, and currently there are no proven methods to preserve fertility in early pubertal transgender adolescents."
So the article's author's best piece of evidence actually says puberty blockers permanently reduce bone density, might affect cognitive function, and might well leave you sterile.
Can an 11 year old understand all those risks and make an informed decision to consent to all that? Can you decide at 11 that you never want to have children? Childless adult women in their 20's have trouble getting the NHS to sterilise them because they might change their mind. It's crazy to think children can understand and consent to it.
Testosterone and oestrogen levels influence bone density throughout life. Bone deficiency in males and females tends to decrease in life.
Having said that, hormone levels are dependent on many things and can not be considered in isolation. One big influence on hormone levels especially in more active people, so generally speaking children and athletes is nutrition. What we eat affects our hormone levels, where women are in their menstrual cycle affects hormone levels. Studies who that hormone levels affect other things too, from concentration, to digestion.
It's way too simplistic to say that administered hormones are responsible for decreases in bone density. Studies have also made some indication that trans kids have a higher tendency to come from poorer and more dysfunctional families. Poorer families tend to have poorer nutrition, leading to lower hormone levels, leading to 'moods'. Dysfunctional families can include those with socially illiberal views and values.
It would need a sizeable control group to undertake such a study as to take in all of the factors, and not inconsiderable resources. If you ask groups of experts to interpret an incomplete set of data, you'll end up with one of two scenarios, the honest experts saying 'insufficient data' or the less scrupulous introducing conjecture due to their personal biases.
This has proved to be the case with the Tavistock data - there are two competing professional interpretations of the same limited data leading to polar different opinions.
This is not the way to do science. Science needs a sizeable control group. Tavistock kids were all seen due to their transgender traits, being they did not also have access to a sizeable group of cisgender kids to include in their so-called scientific study, their could be no complete data set to interpret.
Otherwise the root of campaign as quoted in parliament by Badenoch is the Kiera Bell case. Bell largely won her case on the first round but some ground was lost in the second round.
My thoughts about Bell. Well we now know that she lied to the Tavistock for whatever reason. She had told the Tavistock that she was a lesbian and did not sleep with boys. We now know from her contemporaneous friends that she was very generous with her favours to boys. It is reported that she had an abortion at about the age of 16. Nobody questioned her Gillick competence for that procedure at that time it seems.
She made the decision to have her breasts removed at the age of 22, while no longer being under Tavistock. Whatever people think they know about Bell, they are probably relying more on conjecture than fact.
Cass said that the situation was contentious. She said that the contentious questions could not be answered. Yet her position is more often portrayed as having said that puberty blockers are irreversible and dangerous.
The most difficult question is whether puberty blockers provide valuable time for children and young people to consider their options, or whether they ‘lock in’ children and young people to a treatment pathway
Dr Hilary Cass
This question does expose a gap in Cass's thinking. She considers the puberty blockers provide thinking time. It isn't about thinking time for trans girls, it's about preventing their bodies going through 'testosterone poisoning' before being judged by adults to be competent to make their own decisions.
It simply doesn't wash for the GC brigade to say on one hand that those who have gone through male puberty should be banned from x, y, and z places, activities and professions on the one hand, only then to say that trans girls should go through male puberty because the science is unclear. This is tantamount to placing a lifetime ban to being a trans individual, all the time stigmatising them as sex deviants and offenders, despite never having committed a sex offence.
When you say 'I'm not prepared to be kind', it seems to me to be saying, 'I'm prepared to be cruel'.