Water is one of the most essential substances in human life. It makes up roughly 60% of the human body, or about 40 litres in the average adult, and supports nearly every process that keeps us alive. It is so fundamental that when scientists search for life beyond Earth, water is one of the first things they look for.
Here on Earth, water sustains ecosystems, shapes climates, and supports every living organism. In the human body, it helps transport nutrients, regulate temperature, remove waste, and maintain normal cellular function. What makes water so remarkable is not just its abundance, but the unique chemical properties that allow it to do all of this so effectively.
Water is a small molecule composed of two hydrogen atoms and one oxygen atom. Its shape can be compared to Mickey Mouse! Each hydrogen atom forms a covalent bond with the central oxygen atom, completing the valence shells of all the atoms involved. These bonds create a bent molecule, with an angle of 104.5º.
Hydrogen and oxygen aren’t equal partners in a water molecule, though. Oxygen is more electronegative than hydrogen, which means it attracts the shared electrons more strongly. This creates a polar molecule, with a slightly negative oxygen atom and slightly positive hydrogen atoms. The polarity of water is crucial to its many unique properties.
Water is an exceptional solvent, capable of dissolving many different types of substances—this property is why water plays such an essential role in our bodily functions. Blood plasma, which is about 90% water, carries over 100 different solutes that are vital to our health. This highlights the importance of adequate hydration, something we emphasize at the Institute of Holistic Nutrition (IHN). IHN supports holistic approaches to wellness, including the understanding of the role hydration plays in maintaining a healthy body and mind.
The role of hydrogen bonding
Because water is polar, neighbouring water molecules are attracted to one another. This attraction creates hydrogen bonds, which are responsible for many of water’s most important characteristics.
These include:
- High specific heat – Water can absorb and hold a large amount of heat before its temperature changes. In the body, this helps maintain a stable internal temperature. In nature, it also helps moderate environmental temperatures.
- High heat of evaporation – When water evaporates, it removes heat. This is one reason sweating helps cool the body during exercise or in hot weather.
- Expansion on freezing – Water expands when it freezes, making ice less dense than liquid water. As a result, ice floats, which helps protect aquatic life in lakes and rivers during winter.
- High surface tension – Water molecules cling tightly to one another, creating strong surface tension. This is what allows insects such as water striders to move across the surface of water.
These properties may seem simple at first glance, but together they make life possible in ways we often take for granted.
Why hydration matters for health
Water is not only interesting from a scientific perspective, it is also essential for everyday well-being. Adequate hydration supports body temperature regulation, joint lubrication, digestion, circulation, and the movement of nutrients and waste through the body. It also helps keep mucosal tissues, such as the eyes and mouth, properly moisturized.
Hydration can also influence how we feel day to day. Even mild dehydration may contribute to fatigue, headaches, reduced concentration, and lower physical performance. When water intake is too low, the body has to work harder to carry out basic functions that would otherwise happen more efficiently.
Water also plays an important role in kidney health and urinary function. Some studies suggest that increased water intake may help reduce the risk of kidney stones and may support urinary tract health in some individuals. This reinforces a simple but important message: regular hydration is one of the most practical ways to support the body’s natural balance.
A holistic view of hydration
At the Institute of Holistic Nutrition, we encourage students to look at water not just as a beverage, but as a foundational part of wellness. Hydration affects the body as an integrated whole, from physical performance and digestion to cognitive function and overall vitality.
A holistic approach to health means paying attention to the basics that support long-term well-being. Drinking enough water each day is one of those basics. While individual needs vary depending on climate, activity level, diet, and health status, being mindful of hydration is a simple habit that can have far-reaching benefits.
Raise a Glass to Your Health
Water may seem ordinary, but it is truly extraordinary. Its chemical structure gives rise to the properties that sustain life, while its role in the body makes it indispensable to health and wellness.
The next time you reach for a glass of water, it is worth remembering that you are supporting every cell, tissue, and organ in your body. Small daily habits matter, and hydration is one of the most important.
IHN students go through a full functional analysis of water in our Biological Chemistry course; one of the 19 unique courses that make up IHN’s Applied Holistic Nutrition Diploma Program.
Want to experience a taste of what this transformative program is all about? Be a student for a day and sit in on a class!
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References
MediLexicon International. (n.d.). 15 benefits of drinking water and other water facts. Medical News Today. Retrieved April 20, 2023, from https://www.medicalnewstoday.com/articles/290814
Wergin, Allie (2022, September 29). Water: Essential for your body. Mayo Clinic Health System. Retrieved April 20, 2023, from https://www.mayoclinichealthsystem.org/hometown-health/speaking-of-health/water-essential-to-your-body
Department of Health & Human Services. (2000, August 9). Water – a vital nutrient. Better Health Channel. Retrieved April 20, 2023, from https://www.betterhealth.vic.gov.au/health/healthyliving/water-a-vital-nutrient
Centers for Disease Control and Prevention. (2022, June 6). Water and healthier drinks. Centers for Disease Control and Prevention. Retrieved April 20, 2023, from https://www.cdc.gov/healthyweight/healthy_eating/water-and-healthier-drinks.html
Dent Neurologic Institute (2022, August 17). 22 facts about the brain: World brain day. Dent Neurologic. Retrieved April 20, 2023, from https://www.dentinstitute.com/22-facts-about-the-brain-world-brain-day/
Siener R. Nutrition and Kidney Stone Disease. Nutrients. 2021 Jun 3;13(6):1917. doi: 10.3390/nu13061917. PMID: 34204863; PMCID: PMC8229448.
Ferraro PM, Bargagli M. Dietetic and lifestyle recommendations for stone formers. Arch Esp Urol. 2021 Jan;74(1):112-122. English, Spanish. Erratum in: Arch Esp Urol. 2021 Oct;74(8):725-726. PMID: 33459627.
Hooton TM, Vecchio M, Iroz A, Tack I, Dornic Q, Seksek I, Lotan Y. Effect of Increased Daily Water Intake in Premenopausal Women With Recurrent Urinary Tract Infections: A Randomized Clinical Trial. JAMA Intern Med. 2018 Nov 1;178(11):1509-1515. doi: 10.1001/jamainternmed.2018.4204. PMID: 30285042; PMCID: PMC6584323.
Written by Linda Bazinet, BSc MSc
Science Educator & Biological Sciences Instructor
Linda Bazinet holds a Bachelor of Science from the University of Toronto, specializing in Zoology with a major in Biomedical Science, and a Master of Science in Cell Biology from McMaster University. Since 1988, she has taught extensively across post-secondary institutions including Seneca and Sheridan College, covering a broad range of science disciplines such as Biology, Chemistry, Microbiology, Histology, and Environmental Science. Linda currently teaches Biological Chemistry, Human Anatomy & Physiology, Body Metabolism, and Applied Endocrinology at the Institute of Holistic Nutrition, where she brings decades of academic and practical teaching experience to the next generation of holistic health practitioners.