Introduction
The cardiovascular system delivers life to our tissues and organs. Water is an essential ingredient for life, and our bodies are chiefly made of it. Cleveland Clinic reports that water content in our body varies between 55% to 78%, with the brain and heart each composed of 73%. All body systems require water to function optimally, and the cardiovascular system is no exception. Therefore, it is no surprise that any irregularities in water balance have a detrimental effect on cardiovascular health.
In the fight against cardiovascular diseases, the importance of lifestyle measures, such as diet and exercise, is well known, but the importance of hydration is often understated. Thus, it can come across as a surprise that it’s possible to prevent heart disease by simply drinking five glasses of water every day. Science Daily reports that mild dehydration has the same impact on blood vessels as lifestyle factors commonly associated with cardiovascular diseases, such as smoking a cigarette.
Understanding the link between water intake and cardiovascular health can help us toward embracing healthy habits and discarding unhealthy ones. The purpose of this article is to help encourage appreciation of this connection.
How does hydration impact Cardiovascular disease?
Hydration is essential to cardiovascular health, whilst dehydration undermines cardiovascular health on multiple fronts. Reliable statistics that show the proportion of cardiovascular diseases attributed to dehydration are not available yet. Nonetheless, it is an issue that deserves serious attention, given that cardiovascular disease is the leading cause of death worldwide. It is responsible for 32% of all deaths according to the World Health Organization (WHO).
Dehydration alters the balance of hormones, minerals and amino acids that regulate the cardiovascular system. Consequences include disruption of the fluid balance within cells, stiffening of the blood vessels, and increased risk of blood clots.1 When it comes to strokes and heart attacks, blood clots are major culprits.
Thickening of the blood can occur, which makes the heart work harder, thereby raising blood pressure (hypertension). The heart compensates for this by enlarging in size (left ventricular hypertrophy); thus, setting up a vicious cycle that can cause heart failure.
Poor hydration can affect the outcomes of cardiovascular diseases indirectly, for example, causing changes to glucose balance, affecting vascular integrity and blood viscosity. This can worsen already present kidney diseases, thereby increasing the risk of cardiovascular diseases.2
Staying Hydrated
Fluid intake serves as a convenient indication of how well someone is hydrated.3 Safe drinking water is indeed lifesaving, provided it is consumed in the right quantities at the right time. Fortunately, a healthy body senses when it is deficient in water and triggers the thirst sensation.
Since too much of anything is bad, how much water is optimal? The optimal volume of water, or fluid intake, varies depending on health status, age, gender, and body size, among other factors. In essence, hydration requirements differ from person to person.
By and large, the range for recommended daily water intake is between 1.5 to 3 litres. Bear in mind that there may be exceptions, with the lower end of the recommended range being optimal for one person and the higher water volumes being better for others.4 However, according the to the British Dietetic Association, the average adult person assigned female at birth should consume at least 1.6 litres per day and those assigned male at birth should consume at least 2 litres per day. Water means nothing for someone drowning, yet it is everything to someone dying of thirst in the middle of a desert.
For people whose fluid intake is suboptimal, there are several tips for increasing water consumption:
- Eating fruits rich in water, like watermelon and cucumber, could help if not used to drinking lots of water.
- Drinking flavoured water or healthy beverages if there is a dislike of “normal” water.
- Adding water-rich vegetables to the diet.
- Dilute juices, especially when they are concentrated.
- Tracking water intake to ensure it is up to at least 8 glasses per day. Keeping a water intake journal could help, or a metered (marked) water bottle.
- For coffee lovers, alternate consumption of caffeinated and decaffeinated drinks.
- Drinking water alongside a main meal.
- Minimising water loss by reducing exposure to hot and dry conditions.
- Having water easily available when out and about.
The above list is by no means exhaustive. Ultimately, improving water/fluid intake is beneficial in several ways. For example, it helps normalise blood volume. It also reduces the hormone and salt levels in the blood that are linked to cardiovascular diseases.5
Summary
When it comes to cardiovascular diseases, it is widely agreed that prevention is better than cure. cardiovascular diseases, being a major source of mortality, have a devastating effect on the well-being and quality of life. The importance of hydration to cardiovascular health cannot be overstated. It maintains physiological processes that ensure good health. Directly or indirectly, it decreases the risk of cardiovascular diseases by restoring the balance of hormones and minerals that influence the cardiovascular system. In short, it helps prevent cardiovascular diseases.
Dehydration, on the other hand, can adversely affect the structure and function of the blood, blood vessels and heart, respectively. This can result in cardiovascular problems like stroke, heart attack, heart failure and hypertension, among others. Its widespread impact on other body systems (e.g. renal, endocrine and nervous systems) can also have negative knock-on effects on the cardiovascular system. A way to combat dehydration effectively is by (re)hydration. Effective hydration can be achieved by a regular sufficient intake of water (or other suitable fluids). The fluid requirements vary among individuals. This must be considered when planning a hydration regime.
In conclusion, various strategies can help increase water intake. They range from consuming water-rich foods to tracking one’s fluid intake. An understanding of these measures is crucial. It is important to note that any hydration approach must be supported by medical evidence of effectiveness and safety.
References
- Watso JC, Farquhar WB. Hydration Status and Cardiovascular Function. Nutrients [Internet]. 2019 Aug 11;11(8):1866. Available from: http://dx.doi.org/10.3390/nu11081866
- Mewton N, Girerd N, Boffa J-J, Courivaud C, Isnard R, Juillard L, et al. Practical management of worsening renal function in outpatients with heart failure and reduced ejection fraction: Statement from a panel of multidisciplinary experts and the Heart Failure Working Group of the French Society of Cardiology. Arch Cardiovasc Dis 2020;113:660–70. https://doi.org/10.1016/j.acvd.2020.03.018.
- Maughan RJ. Hydration, morbidity, and mortality in vulnerable populations. Nutr Rev. 2012 Nov;70 Suppl 2:S152-5. https://academic.oup.com/nutritionreviews/article/70/suppl_2/S152/1811927?login=false
- Armstrong L, Muñoz C, Armstrong E. Distinguishing Low and High Water Consumers—A Paradigm of Disease Risk. Nutrients 2020;12:858. https://doi.org/10.3390/nu12030858
- Thornton SN. Sodium and cardiovascular disease: a mismatch of physiological regulation and hydration. Am J Hypertens 2012;25:18; author reply 20. https://doi.org/10.1038/ajh.2011.184
