Increasingly, we are being warned that our long-held definition of feminine beauty is not merely amoral, it is also unhealthy.

The latest piece of evidence comes from a National Institutes of Health study: women who frequently use chemical hair straighteners, which was defined as more than four times a year, were twice as likely to develop uterine cancer than those who did not use the products at all. The study did not find that the occurrence of cancer differed by race, but it observed that Black women were more susceptible to the devastating health consequences because they are more likely to straighten their hair and tend to begin doing so at a relatively young age. That’s a jarring warning.

Uterine cancer is relatively rare, but still, this revelation comes from the same group of researchers who linked straighteners, as well as permanent hair dye, to an increased breast and ovarian cancer risk.

In recent years, we have also been told of the terrible toll that fumes from lacquers and acetones in nail salons have on the human body, and how damaging they can be to the men and women who steadily breathe in those toxins while working there. Exposure to those chemicals has been linked to asthma, skin disorders, miscarriages and cancer. Other beauty treatments — skin lighteners, skin tighteners, wrinkle reducers — have known side effects and complications, too.

And yet, people just cannot stop trying to look younger, thinner ... better.

What does it mean to look our best? There is a narrow definition of beauty that is deeply ingrained in the culture and people are willing to take risks, endure discomfort and even pain, to conform to it. The good-looking — not the model, the starlet or the one-in-a-million stunner — but the person whose appearance is pleasant, familiar, likeable. They are valued.

People strive for that. Perhaps they don’t see themselves as conforming but simply aiming to be their best selves, to feel good, to silence their inner critic. It has become almost impossible to tease out whether a person subscribes to a particular sensibility owing to social pressure, personal preference or some frustratingly complex combination of the two.

But this much is certain: the greater the distance between one’s natural attributes and the beauty ideal, the greater the risk in reshaping, retraining and redesigning oneself into a more valued asset. The more marginalised you are, the more difficult it is to be seen as relevant. No one has felt this more than Black women. They are always struggling to claim their full worth.

For generations, the female archetype in the West was long hair, fair-skinned and with a slender physique. The culture has inched away from that. We cast admiring glances a thousand different ways. But our collective gaze still lingers longest on those who are variations on that embedded ideal.

Black women have embraced their natural hair, shared beauty secrets, revelled in skin that is slow to wrinkle. But they have also had to negotiate employers and public spaces that were neither accepting nor nurturing. They might have made strategic decisions about their appearance or they might have made intuitive ones. But there is always the understanding that they are not setting the standard. And so, they will never meet it. The choice is simply deciding how hard they will try.

One could look at former first lady Michelle Obama as a kind of yardstick of effort. In the White House her hair was sleekly blown out by a hairstylist on call. In the immediate aftermath, she wore a more natural texture. Most recently, she has adopted braids.

Despite a heightened emphasis on body positivity, plus-size women — large Black women — in the public eye still have to reckon with the politicisation of their body. Their clothing choices mean something beyond a personal aesthetic gesture. As a culture, we have not got to the point where considering their beauty feels natural. At the moment, they are an intellectual proposition.

For some, sassiness becomes their armour, weapon and self-care. They use it to fend off insults from folks who have no business commenting on their body, but do so anyway as if it’s a whiteboard for laying out an argument about health, fitness and a lack of discipline.

We have struggled to expand our vision of beauty. We make an effort to ensure that fashion shoots and advertising spreads reflect a more inclusive vision. We aim to accommodate.

In March, the House of Representatives passed the Crown Act, which bans discrimination based on certain hairstyles, including braids, cornrows and dreadlocks. The Act, which is an acronym for Creating a Respectful and Open World for Natural Hair, reads in part: “Throughout United States history, society has used [in conjunction with skin colour] hair texture and hairstyle to classify individuals on the basis of race. Like one’s skin colour, one’s hair has served as a basis of race and national origin discrimination. Racial and national origin discrimination can and do occur because of longstanding racial and national origin biases, and stereotypes associated with hair texture and style.”

It took multiple tries to get this Bill passed in the House and that did not happen before the representative Lauren Boebert, a Republican from Colorado voting in opposition to it, derisively referred to it as the “bad hair” Bill. While Joe Biden has indicated that he will sign it, the Bill has yet to be passed by the Senate.

But it is hard to imagine that even if a piece of legislation forbids the firing of a person because they have tight, coarse curls, no legislation will render that hair beautiful in the eyes of those who view the world as Boebert does. Kinky, textured hair is bad in her estimation. But what makes flat, straight hair any better?

The National Institutes of Health study is a warning. Not just about the risks of relaxers and dye jobs, but the dangers and costs of preaching a doctrine that says a particular kind of person is more beautiful, more capable, more valued simply because they look a particular way. That standard is rooted in Whiteness, but the truth is that the standard has become so airbrushed and filtered that no one can actually reach it, even though so many people cannot stop chasing it.

It is no surprise that the things people do to themselves in the name of beauty are questionable. The cultural pressure to look a certain way is extreme, but so are the rewards. It is a pressure that Black women know well. They have borne the brunt of that stress, but no one is exempt. Yet if society opened itself wide to fully welcome the natural beauty of Black women, it would also mean that so many others — in large bodies, with an abundance of crow’s feet and perhaps no hair at all — could stop contorting themselves to squeeze through what is now the narrowest opening.

• Robin Givhan is senior critic-at-large writing about politics, race and the arts. A 2006 Pulitzer Prize winner for criticism, Givhan has also worked at Newsweek/Daily Beast, Vogue magazine and the Detroit Free Press