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Wednesday 4 October 2023 Dublin: 14°C
# no evidence
People with cancer being sold idea of 'healing diets' that can damage their chances of survival
‘People who lose weight during cancer treatment do not live as long and weight loss is preventable.’

MORE IRISH PEOPLE with cancer are trying out non-evidence based diets and treatments that can damage their chances of survival.

Now more than ever before, people are inundated with information about health matters and are being targeted by unqualified individuals who are claiming that non-evidence based diets can help them – when in fact, they can be damaging.

Head of Research at the Irish Cancer Society Robert O’Connor told that there is a growing tide of unqualified individuals who promote non-evidence based beliefs about diet and medicine.

At best they can be a costly distraction, at worst they have the potential to do huge harm to the most vulnerable in our community.

O’Connor told that a lot of that information is not accurate and can be damaging.

Most people feel incredibly overwhelmed when they are diagnosed with cancer and family and friends want to help so inaccurate information can be sent on, sometimes by well-meaning friends.

“People are unaware but this is part of a growing trend of exploitation of vulnerable people.

“Most of the information is coming from America and some people are making very large businesses out of this kind of thing with books and lecture series but they are not qualified, and the information they give out is not based on evidence but it’s very easy for people to be taken in by all of this.”

O’Connor described a lot of the information on diets and courses as “complete quackery”.

He said that it’s important for most cancer patients to try to maintain their body weight but many of these diets will cause patients to lose weight.

There have been cases where people with curable malignancies have been taken in by fads and quackery and come back and they are beyond the help of medicine.

“The guidance is quite simple and straightforward: have a broad mixed diet and exercise. But the fear that is coming out [in social media] all the time is very damaging.

“Most commonly we see people who are on conventional medicine but are also doing extra things on the side where there is zero evidence.

Their doctor may be surprised by their progress and notice that they’re losing weight and then patients will admit to it saying, ‘I read about this diet’.

“People are being taken advantage of and it’s undermining many advances in medicine.”

He added that cancer isn’t the only example and people with cardiovascular and heart problems are also trying treatments they believe are having an impact but then they’ll collapse because their blood sugar levels will be low.

Complaint upheld 

The Advertising Standards Authority of Ireland (ASAI) recently upheld a complaint against a website offering advice in relation to the Ketogenic diet for cancer.

The website of Dublin based nutritional therapist and author, Patricia Daly, offers online courses and webinars aimed at cancer patients or those treating people with cancer. They are priced at around €420 a month.

Ketogenic diets are based on low-carb, high-fat, normal-protein intakes.

The ASAI said the following four paragraphs were extracts from websites – and - both run by Daly:

Achieving ketosis has been shown to not only enhance your response to conventional cancer treatment in pre-trial studies. A ketogenic diet may also have beneficial effect on your tumour markers…

“I have a problem… when health practitioners or doctors state that they didn’t take a specific therapy into consideration because they’re waiting for the randomised placebo-controlled trials to advise clients.

“This is the case with the ketogenic diet for cancer patients, for instance. There were various reasons why I feel uncomfortable with this 100% evidence-based approach and why, three years ago, I decided to start guiding cancer patients through the process of implementing the ketogenic diet although large human clinical trials weren’t – and still aren’t – available.

Cancer cells need glucose to thrive and carbohydrates turn into glucose in your body; lowering the glucose level in your blood through a low carb and protein diet serves to literally starve the cancer cells to death.

The ASAI directed that the advertiser not refer to the efficacy of the Ketogenic diet in relation to cancer treatment as appropriate evidence to substantiate such claims does not exist.

Daly came to public attention last year when she launched a book - The Ketogenic Kitchen - with chef Domini Kemp and which was aimed at people with cancer.

Both Daly and Kemp have rejected the ASAI’s ruling and both the authors and publishers (Chelsea Green) are considering whether to appeal the recent ASAI decision.

In a statement Daly told

The ruling asserts that a website operated by nutritional therapist Patricia Daly makes false claims. This is not the case, throughout her website and cookbook, Ms Daly has emphasised that research into the ketogenic diet is pre-clinical. It is made clear in all publications, including advertisements, that there are limitations to the use of the ketogenic diet and that it is NOT a one-size-fits-all approach.

Daly added that she is a qualified, insured and registered nutritional therapist with the NTOI (Nutritional Therapists of Ireland), the official register for nutritional therapists and that she adheres to the code of practice of this body.

She also said that her main client base is in the US, where she also receives referrals from oncologists.

The complaint was made jointly by the The Irish Nutrition and Dietetic Institute (INDI) and the Irish Cancer Society (ICS).

Commenting on the report, CEO in INDI Jennifer Feighan said, “The claims made for the Ketogenic diet and its benefits to people with cancer are misleading and unsubstantiated. In this case they have also been made by a person who is not suitably qualified to offer dietary advice to people affected by cancer.”

Weight loss 

Ruth Kilcawley is a senior nutrition support dietitian, specialising in oncology and haematology.

She told, “The problem lies when people feel they are being offered an alternative choice, they’re aware it may not be as effective [as conventional medicine] but they’re not aware of the harm that can come as a consequence of making those choices.

“The people who are offering the choices are not medical doctors so they’re saying you have a choice to follow this to support your treatment but that choice isn’t coming from somebody who has evidence behind them, it’s coming from somebody who wants to make money.

The bottom line is that weight is indicative of survival in cancer. People who lose weight do not live as long and weight loss is preventable.

Kilcawley said that more than 50% of cancer patients are overweight at diagnosis and obesity is a risk factor of cancer development for many cancers.

“What you have on one hand is weight loss is bad in cancer but it’s good in health so that message is confusing for patients.

What the problem is on a scientific level, weight loss is indicative of loss of lean body mass muscle tissue in the body and when you lose muscle tissue in the body, you’re at a higher risk of getting sick from your chemotherapy treatment. The more sick you get, the less treatment that you get, the poorer your outcome and the poorer your quality of life.

“People with advanced disease, if they lose muscle, they can’t get off the chair. They can’t make themselves a cup of tea and so their quality of life is severely impaired if they lose their muscle mass.

“The number one reason why we don’t recommend any restrictive dietary plan in cancer is the risk of losing muscle mass because it predicts survival and quality of life and illness and infection from chemotherapy.

Any of the diets that are promoted for treating cancer, outside conventional health care will result in weight loss due to restriction of food intake because they are very hard to follow and usually mean eliminating a food group, like eliminating dairy or meat or carbohydrates.

shutterstock_218263987 Shutterstock / Yotka Shutterstock / Yotka / Yotka

Kilcawley said, “If you eliminate a major food group from your diet even when you’re well, you’re at risk of eating less then you need and therefore going into negative energy balance and thereby losing weight and muscle mass.

“If you’re sick, the risk of losing the muscle mass is much higher because you’re already unwell and your body can be burning more energy and with nausea and vomiting and side effects of chemotherapy, you’re already going to be eating less anyway.

“So then to on top of that by eliminating food on purpose because you think you’re going to do better results in weight loss which has an evidence based effect of increased toxicity from treatment and poor survival and poor quality of life.”


Head of Research at the ICS Robert O’Connor said, “People need information and we’re adjusting to social media but the vast majority of information on social media is just clickbait, designed to thrive on fear and that fear is having a real impact on people.”

He also urged family and friends of people diagnosed with cancer to avoid spreading this information, even though it is well-meaning.

“Be careful about sources and information – only look for reliable information from reliable sources.

We urge those who have concerns about diet and cancer to speak to their doctor or to a qualified medical professional and not to be taken in by unsubstantiated lifestyle advice from websites or media.

“There is no regulation whatsoever, there is nothing anybody can do about it and it will take people in.”

He added, “If we made a false claim in the Irish Cancer Society and we were in breach, we’d be reported to charity regulator. We need some policing of this.

“We would hope social media organisations like Facebook and Twitter might start to recognise their role in what is going on with the misinformation in health.”

Earlier this year, Australian ‘wellness’ blogger Belle Gibson was found to have breached consumer laws – misleading people – in court. She built her business on claims she beat cancer using alternative treatments and diet changes. She later admitted to having made up her diagnosis.

However, before that, her firm had built up a huge following and fortune with The Whole Pantry website, app and book. The Victorian Federal Court is due to deliver its rulings on sanctions and penalties later this year.

If you, or anybody you know, has been affected by diets claiming to support cancer treatment, please email the author below. 

Read: Chocolate could encourage nurses to get flu vaccine, committee hears>

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