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Does sparkling water damage teeth? Is beetroot juice good for blood pressure? Do vapes damage our health?

Debunking healthcare myths – researchers at University of Galway answer questions from the public about health claims

The Covid-19 pandemic alerted us all to the importance of checking facts, as scientists worked hard to substantiate or refute emerging claims about the prevention and treatment of Sars-CoV-2 – the new strain of coronavirus that caused a global public health emergency from January 2020 to May 2023.

The research project iHealthFacts was initially set up at the University of Galway to debunk misinformation surrounding Covid. However, in late 2022 it was relaunched to answer myths around more general health claims about everything from purported benefits of specific foods to the potential dangers of vaping.

“Some people find themselves overwhelmed with information, particularly with information about what they can do to improve and protect their health,” says Prof Declan Devane, professor of health research methodology at the University of Galway and principal investigator with iHealthFacts.

Acknowledging how unreliable information on health spreads so fast now on social media, instant messaging, etc, Prof Devane says the aim is to tackle the “poorly informed choices, under or overuse of health interventions or treatments and avoidable waste and human suffering”. Dr Philip Crowley, GP and national director of strategy and research at the Health Service Executive, adds that another role of the project – which is funded by the Health Research Board and the HSE – is to reinforce the value of evidence-based healthcare advice from a safe source.


“Things that cause and cure cancer and sleep are the two biggest categories of questions asked by the public,” explains Dr Paula Byrne, lead researcher with iHealthFacts. Up to 200 questions submitted by the public are currently being processed, with answers already available for 60 of these.

“We don’t answer people’s individual medical queries,” explains Dr Byrne. Instead, the questions answered are prioritised based on how often the question is asked, how serious the consequences might be if someone acted on the claim, and the potential to improve health decisions by answering the claim.

Dr Byrne says she is always cautious when people say “the science says this”.

“Science is a process and it’s very rare to have black-and-white findings,” she explains. “There are lots of shades of grey.”

The submitted health claims are analysed by the team of researchers who “research the research”. In other words, the so-called “hierarchy of evidence” is explored, with greater value placed on systematic reviews of randomised controlled trials (in which a hypothesis is investigated with test and control groups) than observational studies.

“Just because something is associated with something else doesn’t mean it has caused it,” says Dr Byrne. “Probably the most important part of this research project is to help people think critically. The bottom line is that we can only go on the evidence that we have at a particular point in time; after that you are speculating.”

As well as reading the short answer to the specific question, members of the public can scroll down to read the studies the researchers drew on to come to their conclusions, with important caveats at the end under the heading “things to remember”.

Dr Byrne explains how another aspect of the project is to tease out what exactly misinformation is. “We present the evidence as it is. We don’t take sides, yet evidence plays a small role in people’s decision-making. We all think we are very rational, but it’s important to remember that we bring certain values to every decision.”

By way of example, she cites how there isn’t much evidence to say that lavender can help insomnia, yet there was a small study of women with insomnia who fell asleep more quickly when they took lavender. “People will take a values-based decision on whether to act on this information or not,” says Dr Byrne.

Some questions answered by researchers on

Do drinks containing aspartame increase the risk of cancer?

“While some studies have found a link between aspartame and cancer, others have not. Aspartame could possibly cause cancer, but there is not enough evidence, and more research is needed in order to be sure.”

Does vaping (using e-cigarettes) impact our health and that of those next to us?

“We found some evidence that vaping is associated with asthma and poorer cardiovascular health. We didn’t find any evidence on the risks of second-hand exposure to vaping. However, because of the design of most of the studies we found, we can’t be sure of the results or say that e-cigarettes were definitely the cause of poor health.”

Under the heading of guidelines and recommendations, the researchers added that the World Health Organisation considers e-cigarettes harmful to health. And, that the HSE says they “are not confident that vaping is a safe or effective way to stop smoking and recommends other options”.

Do collagen supplements make a difference in skin ageing?

“Collagen supplements appear to make skin more hydrated and elastic and also reduce wrinkles, according to recent studies. However, some of the studies we found measured different types of collagen and some of the studies could have been biased, making it difficult to know for sure.”

Does sparkling water make a difference to tooth health?

“We could not find any studies on this question. However, this is evidence that some brands of carbonated water have levels of acidity that could be a risk factor for dental erosion which is a form of tooth damage.”

Does beetroot juice lower blood pressure?

“The systematic reviews suggest that drinking beetroot juice may help lower blood pressure, particularly systolic blood pressure, which is the top number in a blood pressure reading and is a measure of how hard your heart pumps blood during a heartbeat.”

Does manuka honey help lung function?

“We didn’t find any evidence that manuka or any other type of honey has an effect on lungs in general. We found some evidence that honey might help a cough but this is from small studies with few participants, so we can’t be sure.”

Does qigong make a difference to arthritis and mental health?

“We found some studies that said qigong may improve pain, stiffness and physical function in people with arthritis but these studies are small, involving few people. Other studies contradict this finding, so we can’t be sure.”

“We found some studies that suggest that qigong reduces stress, anxiety and depression but others found no difference. Again, this is based on a few studies with small numbers of people so we can’t be sure of the findings. It may be that sticking with qigong for a longer period of time works, but there is not enough evidence to say for sure.”

Is exercise good for long Covid?

“We found that there is limited evidence on the effect of exercise on long Covid. Some studies reported that exercise can be helpful for the long-lasting effects of Covid-19 but others found that there was no difference in whether people with long Covid do exercise or not. However, the evidence isn’t very strong when it comes to how well exercise works and how safe it is in people with long Covid.”

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Sylvia Thompson

Sylvia Thompson

Sylvia Thompson, a contributor to The Irish Times, writes about health, heritage and the environment