Functional water (fact or fad?)

In today's health-conscious world, staying hydrated is not just about drinking water; it's about maximising the benefits with every sip. Enter functional water, the latest innovation in the beverage industry that claims to offer more than just hydration, but provides added health benefits tailored to individual needs. It’s fair to say we entered into researching functional water with a rather skeptical mindset. While some ingredients found in functional water have been studied and found to have promising potential health effects, simply adding an ingredient or ingredients to water and assuming that it will have the same biological effect feels short-sighted. Furthermore, functional water may not be as tightly regulated as pharmaceuticals. This means that manufacturers are likely not to be required to provide robust scientific evidence to support their health claims. Without adequate regulation, there's a risk that some products may overstate their benefits or contain misleading information. So, with this mindset, we set out to explore whether any of these functional waters are substantiated by scientific evidence.

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What is functional water?

Functional water goes beyond traditional hydration by incorporating additional ingredients known for their health-promoting properties. These can range from vitamins and minerals to herbs, antioxidants, and electrolytes, each designed to serve a specific purpose, whether it's boosting energy, enhancing recovery, maximising hydration, or supporting overall wellness.

The rise of functional water

The market for functional water has experienced substantial growth in recent years, driven by increasing consumer interest in health and wellness, coupled with a growing demand for convenient, on-the-go hydration solutions, and some clever marketing and hype thrown in. With ongoing research and development in the field of functional ingredients, the market for functional water is poised for continued expansion as consumers prioritise health and wellness in their beverage choices.

Functional water variants

Electrolyte-water

Electrolytes added to water are essential for hydration and supporting various bodily functions. These include sodium, potassium, calcium, and magnesium, which regulate fluid balance, nerve function, muscle contraction, and pH levels in the body. The importance of electrolyte-enhanced water, especially during periods of increased fluid loss, such as intense physical activity or illness is undisputed. Athletes, in particular, benefit from replenishing electrolytes lost through sweat to prevent dehydration and muscle cramps. Additionally, electrolyte-added water aids in restoring electrolyte balance during dehydration caused by vomiting, diarrhoea, or fever.

What does the research say?

However, with many electrolyte drinks aimed at more health-conscious individuals, the omission of sugar from these electrolyte drinks has become common; examples being brands such as Gatorade-zero, and SueroX. With glucose being a recognised helper in electrolyte absorption, an important question to ask is whether sugar-free electrolytes replenish losses more effectively than water. The research produced minimal and conflicting results to this question. One study found that consuming a sugar-free electrolyte was more effective than water after moderate-intensity exercise (Liang et al., 2022). Another found a sugar-free solution not to be statistically different from water (Millard-Stafford et al., 2021). Finally, a third found an electrolyte drink sweetened with xylitol to have an unfavourable effect on the participants' metabolic profile and kidney function; in addition to producing unpleasant gastric effects (Wołyniec et al., 2022).

In summary, there is little dispute that electrolyte drinks containing sugar are superior compared to sugar-free ones. The verdict is out as to whether sugar-free ones are superior to water when looking to rehydrate after or during exercise.

Vitamins and minerals

Water with added vitamins or minerals (often with added flavours), such as Vitamin water and Glaceau, are marketed to provide a convenient way to supplement daily nutrient intake while staying hydrated. The process of adding vitamins and minerals to water has mainly been studied with the aim of developing strategies to prevent deficiencies in at-risk populations. The evidence does suggest that adding vitamins and minerals to water could indeed be a valid strategy to prevent specific such issues. In healthy individuals, vitamin and mineral-fortified waters are marketed to meet specific health goals, for example, waters with added antioxidants, vitamin C, vitamin D, calcium, and zinc, to boost immunity and support overall health.

What does the research say?

While each individual micronutrient must be researched to ensure its bioavailability in water and any benefits and risks assessed, it appears to be a valid concept. It has been found that vitamins in water allow the body to absorb them at a faster rate than can be delivered with traditional food products (Polaki & Yarla, 2014.). Furthermore, vitamin-fortified water is a shelf-stable, ready-to-use product (Watzke, 1998), and studies have suggested that the calcium in mineral water is at least as bioavailable as that of dairy sources (Heaney, 2006; Bacciottini, 2006). While research in healthy individuals is hard to come by, studies have found that water with added folic acid, vitamins B6, B12, D, and calcium, has been successful in producing favourable changes in at-risk populations (Tapola et al., 2004).

It should be added that, while fortified water can be a convenient way to boost nutrient intake, it's essential to ensure that the added vitamins and minerals are present in appropriate amounts to avoid potential adverse effects from excessive consumption; especially if fat-soluble vitamins such as A, D, and E are being added. In a largely unregulated industry, this is not a guarantee so it’s important to do your own research.

Overall, the evidence suggests that vitamin and mineral-added water can be a valuable component of a balanced diet, providing essential nutrients to support health.

Herbs and botanicals

Herbs and botanicals have long been recognised for their potential health benefits, and infusing water with these natural ingredients has gained in popularity. Examples of popular brands are Bigelow, and Twining’s. Scientific evidence supports the idea that certain herbs and botanicals contain bioactive compounds with antioxidant, anti-inflammatory, and antimicrobial properties, which could potentially translate to health benefits when consumed in water. For example, ginger may help combat oxidative stress and inflammation in the body (Askari et al., 2020). Additionally, studies have shown that infusing water with herbs like clove or thyme can impart antimicrobial properties, potentially reducing the risk of waterborne illnesses (Parham et al., 2020).

What does the research say?

While not comprehensive, the research surrounding infusions and positive health benefits is promising. Herbal infusions have been found to be an easy source of biologically active natural compounds (polyphenols), which when dissolved, are more easily absorbed (Studzińska-Sroka et al., 2021). These polyphenols, to different degrees, can reduce the effects of elevated blood sugar (Studzińska-Sroka et al., 2021). More specifically, sleep quality improvements and glycaemic control have been found by using German chamomile, improved osteoarthritic stiffness and hormone control through using spearmint, and oxidative stress reductions in lemon balm (Etheridge & Derbyshire, 2020)

While more research is needed to fully understand the health impacts of consuming individual herbs and botanicals in water form, the available evidence suggests that herbal-infused water could be a convenient and flavourful way to support overall health and well-being.

Collagen

Collagen supplementation has been strongly indicated to have a range of benefits including pain management, balancing blood sugars, wound healing, skin aging, and post-exercise body composition and strength (Steele, 2022). With the relative abundance of collagen-waters on the market we delved into the research to try and find information regarding pre-prepared bottled collagen waters.

We could not find any studies to either support or disprove its efficacy or bioactivity.

Chlorophyll

Chlorophyll water is infused with chlorophyll, the green pigment found in plants that aid in photosynthesis. Advocates claim it offers various health benefits, including detoxification and antioxidant properties.

What does the research say?

Scientific evidence supporting these claims is limited. Furthermore, we were unable to find any studies using specifically chlorophyll in water. Studies in rodents have shown that chlorophyll may have some anti-cancer properties (Vaňková et al., 2018; de Vogel et al., 2005). Chlorophyll has also been found to have antioxidant and anti-inflammatory properties (Martins et al., 2023). To date, many of the studies surrounding the effects of chlorophyll have not been conducted in humans, and the few that exist involve doses much higher than are found in chlorophyll water.

With no conclusive evidence to support the use of chlorophyll as a controlled supplement, the usefulness of chlorophyll diluted in water is far from being a scientifically proven health aid.

Adaptogens

Adaptogens are a class of compounds that have been used in various traditional medicine systems for their ability to help the body adapt to environmental factors and stressor agents more effectively (de Oliveira & Leitão, 2016). This has led to the rise in water infused with adaptogenic herbs or compounds, marketed to offer stress-relieving and immune-boosting benefits.

What does the research say?

As a class of compounds, adaptogens have been shown to modify cellular stress responses, exert anti-fatigue activity, and improve mental work capacity (Qi et al., 2017; Panossian & Wikman, 2010). These natural adaptogens are also of particular interest because they are quickly incorporated into the biochemical process and are non-toxic (Liao et al., 2018). Studies on individual adaptogens are emerging and for those interested in reading more, this link provides details of many individual adaptogens and their potential effects: https://www.sciencedirect.com/topics/medicine-and-dentistry/adaptogen.

There is some anecdotal evidence supporting the efficacy of adaptogens in reducing stress and improving overall well-being. However, scientific research on adaptogen water specifically is limited, and further research is necessary to validate their efficacy and mechanisms of action in the context of adaptogen-infused water products.

Hydrogen-rich water

Hydrogen-rich water, also known as hydrogen water, has garnered attention for its potential health benefits attributed to its antioxidant properties. Research suggests that molecular hydrogen (H2) neutralises reactive oxygen species in the body which would otherwise contribute to various health issues caused by oxidative stress and inflammation. Hydrogen water is marketed to help with cardiovascular diseases, neurodegenerative disorders, and exercise-induced oxidative damage (and to help with performance and recovery).

What does the research say?

Excitingly, there exist many studies to support these claims. Studies have shown that hydrogen-rich water reduces concentrations of markers of oxidative stress in patients with metabolic syndrome (Nakao et al., 2010; Song et al., 2013), improves lipid and glucose metabolism in patients with type 2 diabetes (Kajiyama et al., 2008), and improved exercise-induced declines in muscle function among elite athletes (Aoki et al., 2012). Additionally, hydrogen-rich water may have positive effects on mood, anxiety, and autonomic nerve function (Mizuno et al., 2018).

While further research is needed to fully elucidate the mechanisms and long-term effects of hydrogen-rich water consumption, of all the function waters investigated for this article, this one is the most exciting to us. Existing evidence suggests hydrogen-rich water has promise in aiding many conditions and supporting health.

NOTE: As a highly reactive element, it is questionable how effective ready-to-drink bottled hydrogen water is. For those wanting to test out its potential effects, tablets that you add to water and drink immediately like these: https://amzn.to/431hWzD are more advisable at this time.

So how do I know if my functional water is doing what it says it does?

Our key advice for those wanting to determine whether a functional water is effective is to continuously review the emerging scientific evidence. Look for research and studies that investigate the effectiveness of each ingredient, and ideally how effective it is when added to water. Studies conducted in humans are ideal.

While it's more subject to bias and the placebo effect, you can also look for improvements in your own relevant health markers or symptoms that may indicate bioactivity, such as increased energy levels, improved digestion, enhanced cognitive function, or better athletic performance. If available, objective measures such as biomarker analysis, physiological testing, or clinical assessments may be used to evaluate effectiveness. These measures can provide quantitative data to assess changes in specific health parameters associated with the active ingredients.

Conclusion

We entered into the subject of function waters with a reasonable level of skepticism but we were pleasantly surprised by some of the findings. There is still a long way to go before any health benefits can be stated conclusively. Furthermore, there is another big issue regarding how stable any added elements or compounds are when added to water and then kept stored until consumption. As the quest for optimal hydration and health-enhancing beverages continues, it's imperative to approach functional waters with a critical mindset, informed by emerging scientific evidence.

References

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