The importance of water on health

Water is the most abundant element on the earth. It is not only vital for the life of plants and food sources, but also for the optimal functioning of the human body. Without water, critical biological processes within the body could not take place.

The many roles of water within the body

The body is made up of about 60 percent of water. Water is needed for moisturising and protecting organs and tissues, increasing overall energy, cellular transmission and communication, regulation of body temperature and excretion of toxins. Simply put, water is part of and surrounds every cell in the body and it is involved with every biochemical reaction that takes places within the body.

There is evidence to show that the importance of drinking water and staying well hydrated is critical to certain health conditions and chronic diseases.

Dehydration and fatigue

Multiple studies done on athletes found a connection between increased fatigue and lowered performance and dehydration.

In a study published in 2016, fifty women diagnosed with multiple sclerosis were examined to assess how hydration affects symptoms of fatigue. Patients with good hydration status reported lower fatigue scores than did women with a low hydration status.1

When you are dehydrated, a decreased amount of fluid causes a decrease in blood volume. This makes the heart work harder to push oxygen to other organs like the brain, skin, and muscles. This lack of oxygen to major organs causes fatigue.

Water intake and weight loss

In addition to helping you to have more energy, being well hydrated is associated with loss of body weight. This happens via two mechanisms, decreased feeding and increased lipolysis (or fat used for energy). Inversely, chronic, mild dehydration is correlated with an increased body weight. 2

In animal studies done on rats, stimulating the drinking response increased the rodents’ need to drink water. This was associated with a decrease in food intake and a decrease in body weight, mainly through fat loss.3,4, 5,6

Animal research has provided insight into how keeping well-hydrated increases metabolism and leads to weight loss.

Water intake and digestive health

Hippocrates, the father of medicine, stated that “all disease begins in the gut.” Fast-forward to modern day and research justifies exactly the same statement. It is vital to keep the intestinal tract healthy in order for nutrients to be absorbed and for the enhancement of the immune system.

With today’s overly processed diet, constipation is an increasing phenomenon among many people. If a person has chronic constipation, this affects one’s microbiome in a negative way.

The microbiome is the term given to the vast and diverse set of bacteria, viruses, and parasites found in the intestinal tract. Research shows that the diversity of the microbiome is integral to the optimal functioning of the intestines and other organs. When one has constipation, this serves as a feeding ground for “bad” bacteria that can weaken the immune system and increase one’s chances of autoimmune disease (including autoimmune diseases of the skin like psoriasis).

Keeping well-hydrated is one of the most basic therapies needed to combat constipation. In a study done on 101 healthy, young female students, intake of prebiotic and probiotic fermented milk increased stool frequency, prevented dryness of the skin and a significant difference was observed between the intake group and the non-intake group in regard to clearness of the skin.7 In this study, liquid (as milk contains water), as well as the intake of “good” bacteria, seemed to contribute positively to the health of the intestine and skin.

Pregnancy is a condition that predisposes a woman to constipation. This is due to a reduced gastrointestinal motility by an increase in the concentration of progesterone during pregnancy. Despite this hormonal change, in a review performed in 2015 to assess the effects of proper hydration in pregnant women, drinking at least 8 glasses of water was shown to prevent constipation.8

Dehydration and brain function

The brain also needs water to function optimally. Research shows that even mild, chronic dehydration can decrease cognitive ability.

In a study performed on twenty-six men in the British Journal of Nutrition, mild dehydration was associated with adverse changes in vigilance and working memory and increased tension/anxiety and fatigue.9

The importance of water for the skin

The skin is the largest organ of the body. Some of its functions include regulating body temperature and producing vitamin D. The skin contains water within many of its layers and without it, the skin can become dry and look more aged.

Cutaneous water content is known to play an important role in different skin functions and water deficiency is associated with several dermatological dysfunctions.10, 11, 12

A 2015 study tested the direct relationship between cutaneous functions and regular dietary water consumption. A Food Frequency Questionnaire was used to measure the total water intake in a group of fourty-nine healthy female volunteers to understand the impact of dietary water on normal skin physiology. The women were divided into two groups, one of which consumed less water and the other of which consumed more water, respectively. Then, both groups were asked to supplement their normal water consumption with a fixed amount of water for four weeks in order to establish the impact of this surplus on their normal skin physiology. The results showed that in the groups that were initially drinking less water, once they increased their water intake, a dramatic increase in epidermal hydration was observed. The authors of the study concluded that a higher water input in one’s regular diet might positively impact normal skin physiology, in particular, in those individuals with lower daily water consumption.13

Another study that looked at the hydration level in relation to ageing and the formation of wrinkles, found that skin hydration significantly lowered wrinkles and the depth of the wrinkle furrows.14

How much dietary water is needed for optimal health?

The “Dietary Guidelines for Americans 2010”report establishes an adequate water intake of 3.7 and 2.7 litres per day for men and women, respectively. The European Food Safety Authority (EFSA) recommends daily water intake of 2.0 and 2.5 litres of water per day for women and men, respectively.

Although different governing bodies recommend different amounts of water, one can drink 35 millilitres of water per kilogram of body weight of water to make sure they are drinking enough. For example, a 70-kilogram person would need 2.5 litres of water per day.

Recommendations for increasing daily intake of water

Since water is such an essential part of the diet for optimal health, it is important to find ways to increase water consumption on a daily basis.

Here are a few tips to increase your daily water intake:

  • Carry a glass or stainless steel water bottle with you throughout the day. Sometimes, the hardest part of drinking more water is remembering to do so. Always having water available considerably increases your chances of remembering to drink more. Glass or stainless steel bottles are preferred over plastic bottles as they do not contain chemicals like BPA, which can act as an endocrine disruptor.

  • Increase consumption of fruits and vegetables. Fruits and vegetables naturally contain higher amounts of water. Therefore, you should aim for three to four servings of fruit and five to seven servings of vegetables daily.

  • Reduce caffeinated beverages. Caffeine acts as a diuretic and can, therefore, cause dehydration. No more than two caffeinated beverages are recommended per day. As a general rule of thumb, for every caffeinated beverage you drink, drink two glasses of water.

  • Herbal teas count as water. Herbal teas not only offer a great way to hydrate your body, but many also offer tremendous health benefits and antioxidants that contribute to the clarity of your skin. For example, Green tea contains very high amounts of antioxidants that help to clear the skin and help to boost immune function. Drinking two to three cups of green tea per day is recommended.

  • Increase water intake gradually. It can be challenging to drastically increase the amount of water you drink from one day to the next, especially if you do not drink a lot of water. The best thing to do is to increase your water intake by one glass every two days. This way, you can ease into drinking more water.

  • Don’t let increased toilet visits deter you from drinking more water. Many people do not want to drink more water because they are concerned that more toilet visits will disrupt their busy schedules. Although this can be an inconvenience, in the beginning, drinking more water on a consistent basis will actually lead to fewer toilet visits. This is because the body gets used to the increased amount of water intake and adjusts its need to get rid of excess water accordingly.

Water is the secret key to disease prevention

Water may be a substance that is taken for granted in terms of how it can positively affect health. However, research shows that proper hydration is integral to combating fatigue, boosting weight loss efforts, enhancing digestive health, maintaining optimal cognitive function and protecting the skin from premature ageing. Decreased consumption of water is associated with increased risk of disease development and drinking the right amount of water is essential in disease prevention.


References and Sources:

  1. Malkki, Hemi. “Multiple sclerosis: Dehydration might contribute to fatigue in MS.”Nature Reviews Neurology 12, no. 10 (2016): 555-555. doi:10.1038/nrneurol.2016.139 [Accessed March 6, 2017]
  2. Fetissov, Serguei O., and Simon N. Thornton. “Hypovolemia-induced obesity and diabetes.”Metabolism 58, no. 11 (2009): 1678. DOI:1016/j.metabol.2009.06.022 [Accessed March 6, 2017]
  3. Porter JP, Anderson JM, Robison RJ, Phillips AC..Effect of central angiotensin II on body weight gain in young rats. Brain Res (2003) 959:20–8.10.1016/S0006-8993(02)03676-4 [Accessed March 6, 2017]
  4. Porter JP, Potratz KR..Effect of intracerebroventricular angiotensin II on body weight and food intake in adult rats. Am J Physiol Regul Integr Comp Physiol (2004) 287:R422–8.10.1152/ajpregu.00537.2003 [Accessed March 6, 2017]
  5. Ortiz RM, Kobori H, Conte D, Navar LG..Angiotensin II-induced reduction in body mass is Ang II receptor mediated in association with elevated corticosterone. Growth Horm IGF Res (2010) 20:282–8.10.1016/j.ghir.2010.03.003 [Accessed March 6, 2017]
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  7. Mitsuyoshi, K. A. N. O., Norie MASUOKA, Tomoe KONNO, Yumiko SUZUKI, and Kouji MIYAZAKI. “Effect of probiotic and prebiotic fermented milk on skin and intestinal conditions in healthy young female students.”Bioscience of Microbiota, Food and Health 35, no. 3 (2016): 105-112. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4965514/ [Accessed March 6, 2017]
  8. Duarte, S. García, MM Ruíz Carmona, and M. Camacho Ávila. “Prevention of constipation during pregnancy with the hydration.”Nutrición hospitalaria: Organo oficial de la Sociedad española de nutrición parenteral y enteral 32, no. 2 (2015): 31. http://www.aulamedica.es/nh/pdf/10298.pdf [Accessed March 6, 2017]
  9. Ganio, Matthew S., Lawrence E. Armstrong, Douglas J. Casa, Brendon P. McDermott, Elaine C. Lee, Linda M. Yamamoto, Stefania Marzano et al. “Mild dehydration impairs cognitive performance and mood of men.”British Journal of Nutrition 106, no. 10 (2011): 1535-1543. doi:10.1017/S0007114511002005 [Accessed March 6, 2017]
  10. Vergou T, Schanzer S, Richter H. Comparison between TEWL and laser scanning microscopy measurements for the in vivo characterization of the human epidermal barrier.J Biophotonics. 2012;5:152–158. http://onlinelibrary.wiley.com/doi/10.1002/jbio.201100067/abstract [Accessed March 6, 2017]
  11. Rosado C, Rodrigues LM. In vivo study of the physiological impact of stratum corneum sampling methods.Int J Cosmet Sci. 2003;25:37–44. http://onlinelibrary.wiley.com/doi/10.1046/j.1467-2494.2003.00171.x/abstract [Accessed March 6, 2017]
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