'Our sister died of cancer because of our mum's conspiracy theories'

It is getting harder to fight medical misinformation because of the prominence of figures such as Robert F Kennedy Jr, who have previously expressed unscientific views - says oncologist Dr Tom Roques, vice-president of the Royal College of Radiologists, which also represents cancer specialists.

When you have a US health and human services secretary "who actively promotes views like the link between vaccines and autism that have been debunked years ago, then that makes it much easier for other people to peddle false views," he says.

"I think the risk is that more harmful alternative treatments are getting more mainstream. That may do people more active harm."

Since becoming Health and Human Services Secretary, Mr Kennedy has said he is not anti-vaccine, and that he just supports more safety tests.

Paloma and her twin Gabriel, along with Sebastian and their younger sister, grew up in the small Sussex town of Uckfield, where they were exposed to conspiracy theories at home, her brothers say.

The "soundtrack" to their school runs, Gabriel says, was conspiracy theorist Alex Jones talking about how the Sandy Hook school shooting was staged or 9/11 "was an inside job".

The brothers say it was their father who first got into conspiracy theories, which piqued their mother's interest. The children absorbed outlandish ideas, including that the Royal Family were shape-shifting lizards, says Gabriel. "As a young child, you trust your parents. So you see that as a truth," he says.

Sebastian believes their mum used her ideas as a way of controlling them. On one occasion, Kate Shemirani decided wi-fi was dangerous and switched it off at home, he says, ignoring his pleas that he had to submit GCSE coursework. "That only fed the joy that she had for using her irrational system of beliefs to control me," he says.

According to her sons, Kate Shemirani's anti-medicine views were accelerated in 2012, when she was diagnosed with breast cancer.

Even though she had the tumour removed through surgery, she credits alternative therapies for her recovery and says online how she used a programme including juices and coffee enemas to become "cancer-free". She doesn't use the word cured.

Paloma absorbed some of these ideas, says Chantelle, one of her best friends from school. "Paloma spoke about her mum curing herself, and she believed sunscreen could cause cancer. I remember she used to get burned so badly at school," she says.

After their parents split up, Gabriel and Sebastian became estranged from their mother. But Paloma maintained contact with her, even when she went off to study at Cambridge in 2019.

Her mother kept coming into her room and "being mean", Paloma said in one message, adding that her mother had hit her. Paloma left for a friend's house. She later shared her parting message to her mother with Ander, saying it was "the last straw. You hurt me every time I let you in and I never ever will again. I'm beyond hurt".

Back at university, Paloma seemed to be moving away from her mother's beliefs at times. Chantelle says she began eating meat and using fluoride toothpaste. But both Chantelle and Ander say she remained sceptical about the Covid-19 vaccine and refused to have it.

Paloma was worried about the negative side effects of chemotherapy, Ander tells me, as it can cause fatigue, sickness, hair loss and affect fertility. Nursing staff spoke to Paloma about egg-freezing and wigs when she was diagnosed.

But the charity Cancer Research UK says Gerson therapy can also have severe side effects, including dehydration, inflammation of the bowel, and heart and lung problems.

At some point during the two days in hospital, Ander says, Paloma made up her mind. She decided not to pursue chemotherapy - at least for the time being - and would try Gerson therapy to start with.

On 23 December, Kate Shemirani sent Ander a voice note giving him instructions to drive Paloma to her house, saying she had arranged doctors for her. She suggested Paloma's time with a friend she wanted to see should be limited on Christmas Day - and said in the message that they could "see her for maybe half an hour or whatever here, or they can do it on FaceTime".

Ander says he felt he could not argue. Paloma "was in fight or flight and really just wanted to be taken care of and, you know, not have to make the hard decisions", he says. "Her mum kind of swooped in and took advantage of that."

Kate Shemirani promotes ideas which she recommended to her daughter to a wider public online. A former NHS nurse in the 1980s, she calls herself "the Natural Nurse" on social media.

On her website, she sells apricot kernels for their "potential health benefits" along with nutritional supplements, and offers information and advice.

She charges about £70 for an annual membership to her site, and charges patients - including those with cancer - £195 for a consultation and personalised 12-week programme.

On social media she posts videos promoting her products and sometimes criticises "ill-informed people" for treating cancer with chemotherapy, or "pumping mustard gas into their veins" as she characterises it.

When the Covid pandemic hit in 2020, Kate Shemirani was one of many conspiracy theory influencers who found a wider audience. Her beliefs appeared to have evolved from alternative health ideas to sprawling anti-establishment conspiracy theories.

She promoted the false ideas that the pandemic was a hoax, that vaccines were part of a plan to kill lots of people, and that doctors and nurses should be punished for their part in it all.

In 2021 a Nursing and Midwifery Council panel determined that Kate Shemirani should be struck off as a nurse for promoting misinformation about the pandemic. Several social media companies also suspended her profiles for promoting misinformation. "She went into obscurity," says Sebastian.

But once Elon Musk bought X in 2022, lots of conspiracy theory accounts were reinstated, including Kate Shemirani's. She was also reinstated on Facebook and she joined TikTok.

Her audience has grown again - in the past six months she has had her content viewed more than four and a half million times across the major social media sites. I have found dozens of comments on X where she encourages people to get in touch, including those with cancer.

TikTok says it has now banned Kate Shemirani's account for violating medical misinformation policies. According to Meta, Instagram and Facebook do not allow harmful medical misinformation. X did not respond.

Paloma continued on Gerson therapy. Some of her friends noticed how she became more and more unwell.

On one video call, Chantelle says, Paloma said she had a new lump in her armpit, and her mother had told her it meant that the cancer was going out of her body. "I knew she was really struggling," she says, adding that Paloma told her she had lost control of her bodily functions.

But she says Paloma also said she felt pressured by doctors and friends to reconsider her decision to pursue alternative therapies on their own. Chantelle says she did not agree with the alternative therapy either, but wanted to be there for her friend.

Paloma had mentioned other people trying to change her mind and discussed "cutting them off", Chantelle adds. "I thought I don't want to be cut off especially when she's struggling like this."

Over the months that they spoke on the phone, Chantelle says she noticed that Kate Shemirani was "taking very good care of Paloma". But she does not think Paloma would have made the same decisions without her mother.

"I don't think her ideology was strong enough to make those decisions is my personal belief. People have different opinions about these things, but I think her mum played a massive, massive role into it," Chantelle says.

In March 2024, Paloma ended her relationship with Ander. Other friends and family felt that Kate Shemirani was isolating Paloma from them.

Gabriel says he asked to meet Paloma not long after she was diagnosed but his sister said she could not go out because of the "bad air". Their mother had convinced her that the "damp air" would cause her to become more ill, he says.

Sebastian and Gabriel were so worried that Gabriel started a legal case. He was not arguing Paloma did not have capacity, but he wanted an assessment of the appropriate medical treatment for her.

But events overtook them and the case ended without a conclusion in July - because Paloma had died.