We know the importance of staying hydrated, especially in hot weather. But even for something as simple as a drink of water, conflicting advice and urban myths abound.

Is cold water really bad for your health? What about hot water from the tap? And what is “raw water”? Let’s dive in and find out.

Myth 1: Cold water is bad for you

Some recent TikToks have suggested cold water causes health problems by somehow “contracting blood vessels” and “restricting digestion”. There is little evidence for this.

While a 2001 study found 51 out of 669 women tested (7.6%) got a headache after drinking cold water, most of them already suffered from migraines and the work hasn’t been repeated since.

Cold drinks were shown to cause discomfort in people with achalasia (a rare swallowing disorder) in 2012 but the study only had 12 participants.

For most people, the temperature you drink your water is down to personal preference and circumstances. Cold water after exercise in summer or hot water to relax in winter won’t make any difference to your overall health.

Myth 2: You shouldn’t drink hot tap water

This belief has a grain of scientific truth behind it. Hot water is generally a better solvent than cold water, so may dissolve metals and minerals from pipes better. Hot water is also often stored in tanks and may be heated and cooled many times. Bacteria and other disease-causing microorganisms tend to grow better in warm water and can build up over time.

It’s better to fill your cup from the cold tap and get hot water for drinks from the kettle.

Myth 3: Bottled water is better

While bottled water might be safer in certain parts of the world due to pollution of source water, there is no real advantage to drinking bottled water in Australia and similar countries.

According to University of Queensland researchers, bottled water is not safer than tap water. It may even be tap water. Most people can’t tell the difference either. Bottled water usually costs (substantially) more than turning on the tap and is worse for the environment.

What about lead in tap water? This problem hit the headlines after a public health emergency in Flint, Michigan, in the United States. But Flint used lead pipes with a corrosion inhibitor (in this case orthophosphate) to keep lead from dissolving. Then the city switched water sources to one without a corrosion inhibitor. Lead levels rose and a public emergency was declared.

Fortunately, lead pipes haven’t been used in Australia since the 1930s. While lead might be present in some old plumbing products, it is unlikely to cause problems.

Myth 4: Raw water is naturally healthier

Some people bypass bottled and tap water, going straight to the source.

The “raw water” trend emerged a few years ago, encouraging people to drink from rivers, streams and lakes. There is even a website to help you find a local source.

Supporters say our ancestors drank spring water, so we should, too. However, our ancestors also often died from dysentery and cholera and their life expectancy was low.

While it is true even highly treated drinking water can contain low levels of things like microplastics, unless you live somewhere very remote, the risks of drinking untreated water are far higher as it is more likely to contain pollutants from the surrounding area.

Myth 5: It’s OK to drink directly from hoses

Tempting as it may be, it’s probably best not to drink from the hose when watering the plants. Water might have sat in there, in the warm sun for weeks or more potentially leading to bacterial buildup.

Similarly, while drinking water fountains are generally perfectly safe to use, they can contain a variety of bacteria. It’s useful (though not essential) to run them for a few seconds before you start to drink so as to get fresh water through the system rather than what might have been sat there for a while.

We are fortunate to be able to take safe drinking water for granted. Billions of people around the world are not so lucky.

So whether you like it hot or cold, or somewhere in between, feel free to enjoy a glass of water this summer.

Just don’t drink it from the hose.

Oliver A.H. Jones, Professor of chemistry, RMIT University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Chiropractors in Australia will not be able to perform spinal manipulation on children under the age of two once more, following health concerns from doctors and politicians.

But what is the spinal treatment at the centre of the controversy? Does it work? Is there evidence of harm?

We’re a team of researchers who specialise in evidence-based musculoskeletal health. I (Matt) am a registered chiropractor, Joshua is a registered physiotherapist and Giovanni trained as a physiotherapist.

Here’s what the evidence says.

Remind me, how did this all come about?

A Melbourne-based chiropractor posted a video on social media in 2018 using a spring-loaded device (known as the Activator) to manipulate the spine of a two-week-old baby suspended upside down by the ankles.

The video sparked widespread concerns among the public, medical associations and politicians. It prompted a ban on the procedure in young children. The Victorian health minister commissioned Safer Care Victoria to conduct an independent review of spinal manipulation techniques on children.

Recently, the Chiropractic Board of Australia reinstated chiropractors’ authorisation to perform spinal manipulation on babies under two years old. But this week, it backflipped, following heavy criticism from medical associations and politicians.

What is spinal manipulation?

Spinal manipulation is a treatment used by chiropractors and other health professionals such as doctors, osteopaths and physiotherapists.

It is an umbrella term that includes popular “back cracking” techniques.

It also includes more gentle forms of treatment, such as massage or joint mobilisations. These involve applying pressure to joints without generating a “cracking” sound.

Does spinal manipulation in babies work?

Several international guidelines for health-care professionals recommend spinal manipulation to treat adults with conditions such as back pain and headache as there is an abundance of evidence on the topic. For example, spinal manipulation for back pain is supported by data from nearly 10,000 adults.

For children, it’s a different story. Safer Care Victoria’s 2019 review of spinal manipulation found very few studies testing whether this treatment was safe and effective in children.

Studies were generally small and were of poor quality. Some of those small, poor-quality studies, suggest spinal manipulation provides a very small benefit for back pain, colic and potentially bedwetting – some common reasons for parents to take their child to see a chiropractor. But overall, the review found the overall body of evidence was very poor.

However, for most other children’s conditions chiropractors treat – such as headache, asthma, otitis media (a type of ear infection), cerebral palsy, hyperactivity and torticollis (“twisted neck”) – there did not appear to be a benefit.

The number of studies investigating the effectiveness of spinal manipulation on babies under two years of age was even smaller.

There was one high-quality study and two small, poor quality studies. These did not show an appreciable benefit of spinal manipulation on colic, otitis media with effusion (known as glue ear) or twisted neck in babies.

Is spinal manipulation on babies safe?

In terms of safety, most studies in the review found serious complications were extremely rare. The review noted one baby or child dying (a report from Germany in 2001 after spinal manipulation by a physiotherapist). The most common complications were mild in nature such as increased crying and soreness.

However, because studies were very small, they cannot tell us anything about the safety of spinal manipulation in a reliable way. Studies that are designed to properly investigate if a treatment is safe typically include thousands of patients. And these studies have not yet been done.

Why do people see chiropractors?

Safer Care Victoria also conducted surveys with more than 20,000 people living in Australia who had taken their children under 12 years old to a chiropractor in the past ten years.

Nearly three-quarters said that was for treatment of a child aged two years or younger.

Nearly all people surveyed reported a positive experience when they took their child to a chiropractor and reported that their child’s condition improved with chiropractic care. Only a small number of people (0.3%) reported a negative experience, and this was mostly related to cost of treatment, lack of improvement in their child’s condition, excessive use of x-rays, and perceived pressure to avoid medications.

Many of the respondents had also consulted their GP or maternity/child health nurse.

What now for spinal manipulation in children?

At the request of state and federal ministers, the Chiropractic Board of Australia confirmed that spinal manipulation on babies under two years old will continue to be banned until it discusses the issue further with health ministers.

Many chiropractors believe this is unfair, especially considering the strong consumer support for chiropractic care outlined in the Safer Care Victoria report, and the rarity of serious reported harms in children.

Others believe that in the absence of evidence of benefit and uncertainty around whether spinal manipulation is safe in children and babies, the precautionary principle should apply and children and babies should not receive spinal manipulation.

Ultimately, high quality research is urgently needed to better understand whether spinal manipulation is beneficial for the range of conditions chiropractors provide it for, and whether the benefit outweighs the extremely small chance of a serious complication.

This will help parents make an informed choice about health care for their child.

Matt Fernandez, Senior lecturer and researcher in chiropractic, CQUniversity Australia; Giovanni E. Ferreira, NHMRC Emerging Leader Research Fellow, Institute of Musculoskeletal Health, University of Sydney, and Joshua Zadro, NHMRC Emerging Leader Research Fellow, Sydney Musculoskeletal Health, University of Sydney

This article is republished from The Conversation under a Creative Commons license. Read the original article.