What’s in your water?

Amy Wood - Nutritionist | 16 Oct, 2021

Tapping into tap water

In the UK, we're lucky to have one of the safest drinking water systems in the world. It is carefully monitored by the Drinking Water Inspectorate to ensure the water coming out of our taps supplies us with safe drinking water of acceptable quality. However, you may notice that drinking water at your house tastes different to water in other parts of the country. This is caused by variation in the mineral composition of water, which is down to the geographical location and source.

Hard vs soft?

Some parts of the UK, particularly Eastern and Southern regions of England, have water with a higher concentration of calcium and magnesium – this is known as 'hard water'. The South West of England, Wales, Scotland and Northern Ireland predominantly have 'soft water'.

Hard water is not harmful and may actually be better for many of us, as it provides a slightly higher dose of minerals than soft water and may help contribute towards a healthy calcium intake. It's also the reason you'll find your kettle scales up quickly – scaling is caused by calcium and magnesium deposits from the water.

To filter or not?

While some people prefer the taste of hard water, others disagree. It's the reason why many people choose to invest in a water filter. This could be in the form of a filter jug, or a full filtration system plumbed into the house. Water UK advise that there is no safety benefit to filtering your water, thanks to the rigorous standards in place for tap water in the UK. The only benefit you may experience is a more palatable drinking water, and less limescale in your kettle.

What gets added?

Around 5.8 million of us in the UK receive fluoridated water. This is the process of adding fluorine to municipal water supplies to reduce cases of tooth decay, particularly in children. Fluoridation doesn't affect the appearance, smell, or taste of water. While some concern has been raised around the potential increased risk of fluorosis (excess fluorine in the bones and teeth), there isn't any strong evidence to suggest that water fluoridation at the levels currently used causes this.

Is bottled better?

Many people choose bottled water as their beverage of choice over tap water, claiming improved taste, convenience, and quality. While some bottled waters are sourced from natural mineral springs, others are just bottled tap waters! Brands will often cite their unique mineral composition as the reason for better-tasting water. While it’s true that the minerals are responsible for flavour, several studies involving blind taste tests found that the public showed no preference for either bottled or tap.

Bottled water may present a more convenient option to grab some water when you're on the go, but we cannot ignore the environmental impact. A huge amount of energy is required to pack and transport bottled water, plus the plastic bottles often end up in landfill or littering green spaces or polluting the oceans, leaching toxins as they slowly degrade.

If that's not enough, the cost of bottled water may make you think twice. Two litres of tap water costs around a third of a penny, whereas the equivalent in bottled water (comprised of single serve bottles) costs £2.36 – that’s 708 times pricier!

What about premium products?

Nowadays it isn't just plain bottled water that you'll find on the supermarket shelves. There's a whole category of water products to choose from. But are they worth the hefty price tag?

  1. Alkaline water: You may remember learning about acids, alkaline and pH back at school. Normal tap water generally has a pH of around 7, meaning it is neutral. However, one of the latest trends is to drink water that is purposely alkaline, with a pH closer to around 9. Advocates claim that drinking water with a higher pH can help to neutralise acid within the body, which supposedly has health benefits and helps reduce the risk of diseases like cancer. However, the evidence to support these claims is severely lacking. Our bodies already have specialised mechanisms in place to help maintain our body pH – it is unlikely that alkaline water would be enough to change body pH significantly.
  2. Vitamin water: Waters with added vitamins and minerals have also become a big hit for health-conscious consumers in recent years. But it’s worth taking a closer look at the real health impact of these drinks. Many of us can achieve the recommended intake of all the nutrients we need through our diet. In fact, the advantage of a food-based approach is that it includes nutrients not found in water, such as fibre. By getting everything we need from our food, there isn’t any real evidence to suggest that exceeding the recommended intake of vitamins is beneficial, and there are certain vitamins that can actually become dangerous if consumed in excess, such as vitamin A. If you choose to drink vitamin waters as a substitute for fizzy pop, it can be a good swap providing the product is sugar-free. However, like supplements, vitamin waters are no substitute for a healthy diet.
  3. Flavoured water: If the taste of plain water isn't to your liking, you might be partial to a flavoured water instead. These waters may be more hydrating than high-sugar fizzy pop, but it’s definitely worth checking the label for added sugar. Being marketed as water, it may seem like a healthy choice at first, but added sugar can still sneak onto the ingredients list, which isn’t the best for dental health.

My take out...

With so many water options available, it may seem like a minefield choosing the right way to hydrate. While flavoured waters may be a fun choice to switch things up from time to time, my overall vote goes to the humble tap water. It's essentially free, it creates less environmental impact than bottled water, plus you can flavour it to suit your personal taste in a wide variety of ways – from fresh fruit and herb infusions to cordials and sugar-free squash.

For inspiration on how to jazz up your tap water, check out this blog post: Flavour your water – 9 natural infusions

Nutritionist Amy Wood (ANutr), MSci BSc Nutrition has a keen interest in the relationship between diet and health. Having been published in the European Journal of Nutrition, Amy is passionate about making evidence-based nutrition accessible to everyone and helping others to adopt a food-focused approach to taking control of their health.