How Does Hydration Affect The Heart And Brain?

I conducted a systematic review using Medline and Google Scholar to answer my research questions. I looked at several databases and after reading about each database, I found that the Medline database is most relevant to medical research, but Google Scholar database provided more diverse articles. I used a number of keywords to conduct the literature search (i.g hydration and heart, hydration and brain functioning, effect of hydration on cardiovascular). The articles from the last 20 years were selected in this review to ensure latest research on this topic. I looked over many articles and read the ones relevant to my topic. I also made sure that the articles were not too old to ensure recent research  articles were added in this project. I made sure to include them in my references too.

I conducted a systematic review for my research project.

A total of ten research articles were selected in this systematic review which I read for their  relevance and importance to hydration and human body functioning.

One of the articles I selected explained the effects of dehydration on moods ( Johnston.S et al, 2019). Elderly people's cognitive function is significantly affected during dehydration. Dehydration not only affects the elderly, but also impacts young adults. One study by Kempton MJ et al, (2011) on  healthy adolescents revealed that dehydration may affect executive functions that include planning and visuo-spatial processing. Another study on children revealed that attention was increased for school children by drinking more water (Perry CS et al 2015). The study was performed on 52 children ages 9-12. The experiment involved giving one group of children normal breakfast and the other group an extra 750ml of water over 2 hours and their school performance was observed. The study demonstrated that hydration improves overall school performance and cognitive functioning. A research study on a large number of individuals with migraine, found that dehydration is linked to migraines.                                    

An article I included in this review about the topic of  hydration and cardiovascular health provided new evidence on heart functioning association with low water intake. The article explained that those who chronically take less water are more likely to develop cardiovascular diseases ( Watso JC and Farquhar WB, 2019). A very recent study  (Martinez Garcia et al 2022) mentioned that low water intake is connected to things such as obesity and type 2 diabetes. The study also found hydration is linked to healthier body composition and reduces the risk of cardiovascular diseases. An article I selected on hydration chronic diseases prevention mentioned that mild dehydration can cause several health issues in infants such as  hypertonic dehydration. Mild dehydration can also cause cerebral infarct (blood clot in brain) and hypertension. (Friedrich Manz and Andreas Wentz 2005).

The topic I chose was how hydration affects heart and brain functioning. Based on the number of research studies I included in this systematic review, it has been concluded that hydration has shown to significantly reduce many brain and heart related chronic diseases. Hydration has also been proved that it helps prevent diseases in children and the elderly such as cognitive dysfunction and hypertension. Dehydration can significantly affect the physical and mental state of humans. Dehydration may cause migraines which is a very common health problem in Calgary. Optimum level of hydration is required for the functioning of the brain and heart and to maintain overall good health.

Trangmar SJ, González-Alonso J. Heat, Hydration and the Human Brain, Heart and Skeletal Muscles. Sports Med. 2019 Feb;49(Suppl 1):69-85. doi: 10.1007/s40279-018-1033-y.

Rochette LM, Patterson SM. Hydration status and cardiovascular function: effects of hydration enhancement on cardiovascular function at rest and during psychological stress. Int J Psychophysiol. 2005 Apr;56(1):81-91. doi: 10.1016/j.ijpsycho.2004.10.003.

Pross N. Effects of Dehydration on Brain Functioning: A Life-Span Perspective. Ann Nutr Metab. 2017;70 Suppl 1:30-36. doi: 10.1159/000463060. Epub 2017 Jun 15.

 Young HA, Cousins A, Johnston S, Fletcher JM, Benton D. Autonomic adaptations mediate the effect of hydration on brain functioning and mood: Evidence from two randomized controlled trials. Sci Rep. 2019 Nov 11;9(1):16412. doi: 10.1038/s41598-019-52775-5.   

Kempton MJ, Ettinger U, Foster R, Williams SC, Calvert GA, Hampshire A, Zelaya FO, O'Gorman RL, McMorris T, Owen AM, Smith MS. Dehydration affects brain structure and function in healthy adolescents. Hum Brain Mapp. 2011 Jan;32(1):71-9. doi: 10.1002/hbm.20999.

Watso JC, Farquhar WB. Hydration Status and Cardiovascular Funcion. Nutrients. 2019 Aug 11;11(8):1866. doi: 10.3390/nu11081866.

Martínez García RM, Jiménez Ortega AI, Lorenzo-Mora AM, Bermejo LM. Importancia de la hidratación en la salud cardiovascular y en la función cognitiva [Importance of hydration in cardiovascular health and cognitive function]. Nutr Hosp. 2022 Sep 1;39(Spec No3):17-20. Spanish. doi: 10.20960/nh.04304.

Perry CS 3rd, Rapinett G, Glaser NS, Ghetti S. Hydration status moderates the effects of drinking water on children's cognitive performance. Appetite. 2015 Dec;95:520-7. doi: 10.1016/j.appet.2015.08.006. Epub 2015 Aug 10.

Friedrich Manz, Andreas Wentz, The Importance of Good Hydration for the Prevention of Chronic Diseases, Nutrition Reviews, Volume 63, Issue suppl_1, June 2005, Pages S2–S5.

Arca, K.N., Halker Singh, R.B. Dehydration and Headache. Curr Pain Headache Rep 25, 56 (2021). https://doi.org/10.1007/s11916-021-00966-z.

I highly acknowledgde the support of 5T homeroom teacher Saba Adil for her support and feedback and my parents for their support.