Is cold water bad for you? The facts behind 5 water myths

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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.The Conversation

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.

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  • Fall Asleep In 2 Minutes (Doctor Explains)

    10almonds is reader-supported. We may, at no cost to you, receive a portion of sales if you purchase a product through a link in this article.

    Beyond “sleep hygiene”, Dr. Siobhan Deshauer has insights to share:

    Rest for your body and mind

    First, do still do the basics. That means dimming/filtering lights for an hour before bed, lowering the room temperature a little, ensuring you have nice fresh sheets, not having alcohol or caffeine before bed, and getting out of bed if you’re not asleep within half an hour, to avoid associating being in bed with wakefulness.

    Next, the extra tips:

    • Progressive relaxation: tense and relax each muscle group from toes to head
    • Box breathing: inhale, hold, exhale, and hold for 4 seconds each; helps calm the nervous system (it’s called “box breathing” because of the 4:4:4:4 setup)
    • Diaphragmatic breathing: focus on belly breathing, with longer exhalation to activate the parasympathetic nervous system (note that this can, and even ideally should, be done at the same time as the previous)
    • Cognitive shuffling: think of words starting with each letter of a chosen word while visualizing them (this is like “counting sheep”, but does the job better—the job in question being preventing your brain from moving to anything more strenuous or stressful)

    For more on all of these plus some extra side-along advice, enjoy:

    Click Here If The Embedded Video Doesn’t Load Automatically!

    Want to learn more?

    You might also like to read:

    Non-Sleep Deep Rest: A Neurobiologist’s Take ← a way to get many of the benefits of sleep, while awake

    Take care!

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  • What happens in my brain when I get a migraine? And what medications can I use to treat it?

    10almonds is reader-supported. We may, at no cost to you, receive a portion of sales if you purchase a product through a link in this article.

    Migraine is many things, but one thing it’s not is “just a headache”.

    “Migraine” comes from the Greek word “hemicrania”, referring to the common experience of migraine being predominantly one-sided.

    Some people experience an “aura” preceding the headache phase – usually a visual or sensory experience that evolves over five to 60 minutes. Auras can also involve other domains such as language, smell and limb function.

    Migraine is a disease with a huge personal and societal impact. Most people cannot function at their usual level during a migraine, and anticipation of the next attack can affect productivity, relationships and a person’s mental health.

    Francisco Gonzelez/Unsplash

    What’s happening in my brain?

    The biological basis of migraine is complex, and varies according to the phase of the migraine. Put simply:

    The earliest phase is called the prodrome. This is associated with activation of a part of the brain called the hypothalamus which is thought to contribute to many symptoms such as nausea, changes in appetite and blurred vision.

    The hypothalamus is shown here in red. Blamb/Shutterstock

    Next is the aura phase, when a wave of neurochemical changes occur across the surface of the brain (the cortex) at a rate of 3–4 millimetres per minute. This explains how usually a person’s aura progresses over time. People often experience sensory disturbances such as flashes of light or tingling in their face or hands.

    In the headache phase, the trigeminal nerve system is activated. This gives sensation to one side of the face, head and upper neck, leading to release of proteins such as CGRP (calcitonin gene-related peptide). This causes inflammation and dilation of blood vessels, which is the basis for the severe throbbing pain associated with the headache.

    Finally, the postdromal phase occurs after the headache resolves and commonly involves changes in mood and energy.

    What can you do about the acute attack?

    A useful way to conceive of migraine treatment is to compare putting out campfires with bushfires. Medications are much more successful when applied at the earliest opportunity (the campfire). When the attack is fully evolved (into a bushfire), medications have a much more modest effect.

    https://datawrapper.dwcdn.net/Pj1sC

    Aspirin

    For people with mild migraine, non-specific anti-inflammatory medications such as high-dose aspirin, or standard dose non-steroidal medications (NSAIDS) can be very helpful. Their effectiveness is often enhanced with the use of an anti-nausea medication.

    Triptans

    For moderate to severe attacks, the mainstay of treatment is a class of medications called “triptans”. These act by reducing blood vessel dilation and reducing the release of inflammatory chemicals.

    Triptans vary by their route of administration (tablets, wafers, injections, nasal sprays) and by their time to onset and duration of action.

    The choice of a triptan depends on many factors including whether nausea and vomiting is prominent (consider a dissolving wafer or an injection) or patient tolerability (consider choosing one with a slower onset and offset of action).

    As triptans constrict blood vessels, they should be used with caution (or not used) in patients with known heart disease or previous stroke.

    Nurse takes blood pressure
    Triptans should be used cautiously in patients with heart disease. CDC/Unsplash

    Gepants

    Some medications that block or modulate the release of CGRP, which are used for migraine prevention (which we’ll discuss in more detail below), also have evidence of benefit in treating the acute attack. This class of medication is known as the “gepants”.

    Gepants come in the form of injectable proteins (monoclonal antibodies, used for migraine prevention) or as oral medication (for example, rimegepant) for the acute attack when a person has not responded adequately to previous trials of several triptans or is intolerant of them.

    They do not cause blood vessel constriction and can be used in patients with heart disease or previous stroke.

    Ditans

    Another class of medication, the “ditans” (for example, lasmiditan) have been approved overseas for the acute treatment of migraine. Ditans work through changing a form of serotonin receptor involved in the brain chemical changes associated with the acute attack.

    However, neither the gepants nor the ditans are available through the Pharmaceutical Benefits Scheme (PBS) for the acute attack, so users must pay out-of-pocket, at a cost of approximately A$300 for eight wafers.

    What about preventing migraines?

    The first step is to see if lifestyle changes can reduce migraine frequency. This can include improving sleep habits, routine meal schedules, regular exercise, limiting caffeine intake and avoiding triggers such as stress or alcohol.

    Despite these efforts, many people continue to have frequent migraines that can’t be managed by acute therapies alone. The choice of when to start preventive treatment varies for each person and how inclined they are to taking regular medication. Those who suffer disabling symptoms or experience more than a few migraines a month benefit the most from starting preventives.

    Pharmacy assistant serves customer
    Some people will take medicines to prevent migraines. Tbel Abuseridze/Unsplash

    Almost all migraine preventives have existing roles in treating other medical conditions, and the physician would commonly recommend drugs that can also help manage any pre-existing conditions. First-line preventives include:

    • tablets that lower blood pressure (candesartan, metoprolol, propranolol)
    • antidepressants (amitriptyline, venlafaxine)
    • anticonvulsants (sodium valproate, topiramate).

    Some people have none of these other conditions and can safely start medications for migraine prophylaxis alone.

    For all migraine preventives, a key principle is starting at a low dose and increasing gradually. This approach makes them more tolerable and it’s often several weeks or months until an effective dose (usually 2- to 3-times the starting dose) is reached.

    It is rare for noticeable benefits to be seen immediately, but with time these drugs typically reduce migraine frequency by 50% or more.


    https://datawrapper.dwcdn.net/jxajY

    ‘Nothing works for me!’

    In people who didn’t see any effect of (or couldn’t tolerate) first-line preventives, new medications have been available on the PBS since 2020. These medications block the action of CGRP.

    The most common PBS-listed anti-CGRP medications are injectable proteins called monoclonal antibodies (for example, galcanezumab and fremanezumab), and are self-administered by monthly injections.

    These drugs have quickly become a game-changer for those with intractable migraines. The convenience of these injectables contrast with botulinum toxin injections (also effective and PBS-listed for chronic migraine) which must be administered by a trained specialist.

    Up to half of adolescents and one-third of young adults are needle-phobic. If this includes you, tablet-form CGRP antagonists for migraine prevention are hopefully not far away.

    Data over the past five years suggest anti-CGRP medications are safe, effective and at least as well tolerated as traditional preventives.

    Nonetheless, these are used only after a number of cheaper and more readily available first-line treatments (all which have decades of safety data) have failed, and this also a criterion for their use under the PBS.

    Mark Slee, Associate Professor, Clinical Academic Neurologist, Flinders University and Anthony Khoo, Lecturer, Flinders University

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

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  • Why Do We Have Pores, And Could We Not?

    10almonds is reader-supported. We may, at no cost to you, receive a portion of sales if you purchase a product through a link in this article.

    It’s Q&A Day at 10almonds!

    Have a question or a request? We love to hear from you!

    In cases where we’ve already covered something, we might link to what we wrote before, but will always be happy to revisit any of our topics again in the future too—there’s always more to say!

    As ever: if the question/request can be answered briefly, we’ll do it here in our Q&A Thursday edition. If not, we’ll make a main feature of it shortly afterwards!

    So, no question/request too big or small

    ❝Do we really need pores, and why are they bigger on the face?❞

    Pores secrete sweat or sebum (there are different kinds of pores for each).

    If we didn’t have sweat pores, we’d be unable to sweat, which superficially may seem like a bonus, but it’d make us prone to overheating (like dogs, pigs, and other mammals that cannot sweat).

    If we didn’t have sebum pores (usually called hair follicles, which are supplied by a sebaceous gland), we’d be completely hairless, and also unable to supply our skin with natural oils that keep it healthy. So we’d have no hair and very unhappy skin.

    Which is ironic, because to believe beauty magazines, we must at all costs minimize our pores (and indeed, interventions like botox* can kill them).

    *Let’s give that its full name though:

    Botulinum Neurotoxin Type A in the Treatment of Facial Seborrhea and Acne: Evidence and a Proposed Mechanism

    Suffice it to say, we do not recommend getting injected with neurotoxins unless it is truly necessary to ward off a greater harm.

    As for being bigger on the face, they need not be, but sebaceous glands are more active and numerous there, being most active and numerous in the face/forehead—which is why oily skin is more likely to appear there than other parts of the body.

    If your facial sebaceous glands are too active for your liking…

    …there are ways to reduce that, a simple and relatively gentle way (relative, for example, botox) is with retinoids, including retinols or retinoic acids. Here’s some of the science of that; the paper is about treating acne, but the mechanism of action is the same (down-regulating the sebaceous glands’ action):

    The treatment of severe cystic acne with 13-cis-retinoic acid: evaluation of sebum production and the clinical response in a multiple-dose trial

    The potential side-effects, however were noted as:

    • Cheilitis
    • Desquamation of the skin
    • Pruritus

    Which, in translation from sciencese, means:

    • Chapped lips
    • Flaky skin
    • Itchiness

    Which aren’t necessarily fun, which is why with retinoids are best taken in very small doses at first to see how your skin reacts.

    Remember when we said what your skin would be like without pores? This is what would happen, only much worse.

    Take care!

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  • Radiant Rebellion – by Karen Walrond

    10almonds is reader-supported. We may, at no cost to you, receive a portion of sales if you purchase a product through a link in this article.

    In health terms, we are often about fighting aging here. But to be more specific, what we’re fighting in those cases is not truly aging itself, so much as age-related decline.

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    And yes, embracing, not merely accepting. This is not a downer of a book; it’s a call to revolution. It asks us to be proud of our grey hairs, to see our smile-lines around our eyes as the sign of a lived-in body, and even to embrace some of the unavoidable “actual decline” things as part of the journey of life. Maybe we’re not as strong as we used to be and now need a grippety-doodah to open jars; not everyone gets to live long enough to experience that! How lucky we are.

    Perhaps most importantly, she bids us be the change we want to see in the world, and inspire others with our choices and actions, and shake off ageist biases for good.

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    Click here to check out Radiant Rebellion, and reclaim aging!

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  • The Lost Art of Silence – by Sarah Anderson

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    From “A Room Of One’s Own” to “Silent Mondays”, from spiritual retreats to noise-cancelling headphones, this book covers the many benefits of silence—and a couple of downsides too.

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  • Water Water Everywhere, But Which Is Best To Drink?

    10almonds is reader-supported. We may, at no cost to you, receive a portion of sales if you purchase a product through a link in this article.

    Well Well Well…

    In Tuesday’s newsletter, we asked you for your (health-related) opinion on drinking water—with the understanding that this may vary from place to place. We got the above-depicted, below-described, set of responses:

    • About 65% said “Filtered is best”
    • About 20% said “From the mains is best”
    • About 8% said “Bottled is best”
    • About 3% said “Distilled is best”
    • About 3% said “Some other source is best”

    Of those who said “some other source is best”, one clarified that their preferred source was well water.

    So what does the science say?

    Fluoridated water is bad for you: True or False?

    False, assuming a normal level of consumption. Rather than take up more space today though, we’ll link to what we previously wrote on this topic:

    Q&A: Water Fluoridation

    You may be wondering: but what if my level of consumption is higher than normal?

    Let’s quickly look at some stats:

    • The maximum permitted safety level varies from place to place, but is (for example) 2mg/l in the US, 1.5mg/l in Canada & the UK.
    • The minimum recommended amount also varies from place to place, but is (for example) 0.7mg/l in Canada and the US, and 1mg/l in the UK.

    It doesn’t take grabbing a calculator to realize that if you drink twice as much water as someone else, then depending on where you are, water fluoridated to the minimum may give you more than the recommended maximum.

    However… Those safety margins are set so much lower than the actual toxicity levels of fluoride, that it doesn’t make a difference.

    For example: your writer here takes a medication that has the side effect of causing dryness of the mouth, and consequently she drinks at least 3l of water per day in a climate that could not be described as hot (except perhaps for about 2 weeks of the year). She weighs 72kg (that’s about 158 pounds), and the toxicity of fluoride (for ill symptoms, not death) is 0.2mg/kg. So, she’d need 14.4mg of fluoride, which even if the water fluoridation here were 2mg/l (it’s not; it’s lower here, but let’s go with the highest figure to make a point), would require drinking more than 7l of water faster than the body can process it.

    For more about the numbers, check out:

    Acute Fluoride Poisoning from a Public Water System

    Bottled water is the best: True or False?

    False, if we consider “best” to be “healthiest”, which in turn we consider to be “most nutrients, with highest safety”.

    Bottled water generally does have higher levels of minerals than most local mains supply water does. That’s good!

    But you know what else is generally has? Microplastics and nanoplastics. That’s bad!

    We don’t like to be alarmist in tone; it’s not what we’re about here, but the stats on bottled water are simply not good; see:

    We Are Such Stuff As Bottles Are Made Of

    You may be wondering: “but what about bottled water that comes in glass bottles?”

    Indeed, water that comes in glass bottles can be expected to have lower levels of plastic than water that comes in plastic bottles, for obvious reasons.

    However, we invite you to consider how likely you believe it to be that the water wasn’t stored in plastic while being processed, shipped and stored, before being portioned into its final store-ready glass bottles for end-consumer use.

    Distilled water is the best: True or False?

    False, generally, with caveats:

    Distilled water is surely the safest water anywhere, because you know that you’ve removed any nasties.

    However, it’s also devoid of nutrients, because you also removed any minerals it contained. Indeed, if you use a still, you’ll be accustomed to the build-up of these minerals (generally simplified and referenced as “limescale”, but it’s a whole collection of minerals).

    Furthermore, that loss of nutrients can be more than just a “something good is missing”, because having removed certain ions, that water could now potentially strip minerals from your teeth. In practice, however, you’d probably have to swill it excessively to cause this damage.

    Nevertheless, if you have the misfortune of living somewhere like Flint, Michigan, then a water still may be a fair necessity of life. In other places, it can simply be useful to have in case of emergency, of course.

    Here’s an example product on Amazon if you’d like to invest in a water still for such cases.

    PS: distilled water is also tasteless, and is generally considered bad, tastewise, for making tea and coffee. So we really don’t recommend distilling your water unless you have a good reason to do so.

    Filtered water is the best: True or False?

    True for most people in most places.

    Let’s put it this way: it can’t logically be worse than whatever source of water you put into it…

    Provided you change the filter regularly, of course.

    Otherwise, after overusing a filter, at best it won’t be working, and at worst it’ll be adding in bacteria that have multiplied in the filter over however long you left it there.

    You may be wondering: can water filters remove microplastics, and can they remove minerals?

    The answer in both cases is: sometimes.

    • For microplastics it depends on the filter size and the microplastic size (see our previous article for details on that).
    • For minerals, it depends on the filter type. Check out:

    The H2O Chronicles | 5 Water Filters That Remove Minerals

    One other thing to think about: while most water filtration jugs are made of PFAS-free BPA-free plastics for obvious reasons, for greater peace of mind, you might consider investing in a glass filtration jug, like this one ← this is just one example product on Amazon; by all means shop around and find one you like

    Take care!

    Don’t Forget…

    Did you arrive here from our newsletter? Don’t forget to return to the email to continue learning!

    Learn to Age Gracefully

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