The Mental Health Benefits of Water

Oftentimes when looking to improve mental health, the first ideas to come to mind are things like beginning therapy, exercise or meditation.  One of the most overlooked steps is to simply remain properly hydrated. On average, the brain is made up of 73% water. While every organ in the body needs water to perform its actions properly, brain function can be severely impacted by dehydration—affecting not just physical health, but mental health as well. Unfortunately, individuals struggling with overwhelming feelings of depression or anxiety often forget to drink water or choose caffeinated drinks in an effort to help improve their energy levels. In this next article, I will discuss the mental health benefits of water and a simple experiment you can do for yourself to see what you notice when you are properly hydrated.

The role of water in the bodies of all living species, humans included, has not changed since the earliest creation of life in water. While the human body is entirely dependent on the many complicated functions of water for its survival, it has not developed a water-storage system in the same way it stores fat.  Every day you lose water through your breath, perspiration, urine and bowel movements. For your body and mind to function properly, you must replenish its water supply by consuming beverages and foods that contain water. Most doctors recommend drinking 6-8 glasses of water per day, depending on the individual and ideally should be ingested slowly with small sips throughout the day which can help in strengthening the digestive system and improving metabolism.


What does it mean to be hydrated?

The term hydration is often used in terms of adding water to the human body that has been lost. When someone speaks of being well-hydrated, they mean there is plenty of water in their body. To be hydrated means that each cell membrane is able to hold water in a cell.  However, cellular hydration is not just about water but the electrolytes (aka mineral salts that include magnesium, chloride, calcium, potassium and sodium) it relies upon in the right balance.

The history of “8 glasses of water per day”

You’ve probably heard the advice to drink eight glasses of water a day. The first time a minimal water requirement was suggested as part of an official nutrition guideline in the United States occurred in 1945; that number was 2.5 liters of fluid per day. The more recent theory of 8 glasses per day goes back to 1967 and is accredited to Dr. Irwin Stillman as the earliest source; in his protocol, “The Stillman Diet” specified that a minimum of eight 10-ounce glasses of water per day to “wash away the fatty acids resulting from the breakdown of fat.” In 1974, Dr. Frederick J. Stare co-wrote a book where he mentioned Dr. Stillman’s work, and disagreed on the subject of fluid consumption. He wrote:

“…for the average adult, somewhere between 6 to 8 glasses per 24 hours and this can be in the form of coffee, tea, milk, soft drinks, beer, etc. Fruits and vegetables are also good sources of water.”

More recently in 2017, the Mayo Clinic recommended taking in between 2-3 Liters (or more) per person per day but this might need to be modified based on several factors including: 

  • Exercise: any activity that makes you sweat, you need to drink extra water to cover the fluid loss.

  • Environment: Hot or humid weather can make you sweat and requires additional fluid. Dehydration can also occur at high altitudes.

  • Overall health: Your body loses fluids when you have a fever, vomiting, or diarrhea. Other conditions that might require increased fluid intake include bladder infections and urinary tract stones.

  • Pregnancy and breast feeding: you may need additional fluids to stay hydrated for both.

  • Gender: about 15.5 cups of fluids a day for men, 11.5 cups of fluids a day for women; this covers fluids from water, coffee, tea, other beverages and food.

“Most people can stay hydrated by drinking water and other fluids whenever they feel thirsty. For some people, fewer than eight glasses a day might be enough. But other people might need more.”

You don’t need to rely only on water to meet your fluid needs. Many fruits and vegetables are almost 100% water by weight. However, I do believe for most people, at least 4 cups a day of just water is fundamental for proper hydration. For people with a history of kidney stones, that number needs to be at least 2 quarts a day. It’s still unclear to me whether caffeinated drinks such as coffee or tea can really be counted towards the daily total in hydrating the body given its pronounced diuretic effects. Regular soda, energy, or sports drinks, and other sweet drinks usually contain a lot of added sugar, which may not only provide more calories than needed but are associated with elevated calcium in the urine that can increase the risk of forming kidney stones. 

How can you tell if you are drinking enough water?

Paying attention to your thirst is one of the best ways of maintaining good hydration status.

There also tends to be widespread agreement that one way to prevent dehydration is to observe the color of your urine. The goal is for your urine to be clear to light yellow. If the urine is dark yellow, it’s your body telling you that the urine is too concentrated and you need to be drinking more water.

Water and mental health

Over the last decade, there have been several studies showing the association between daily water intake and depression and anxiety. A research study conducted in 2014 explored the effects of hydration or dehydration on overall mood; the study found that when water intake was decreased, mood was adversely affected. The individuals who reduced their water intake were less calm, more overwhelmed, and more prone to feelings of dissatisfaction. On the other hand, individuals who continually drank an appropriate amount of water were calm and satisfied.

Another study conducted in 2018 demonstrated that people who drank less water had a higher risk of depression and anxiety. 

I ask about water intake when evaluating a new patient. People seem to know that like exercise and eating healthy foods, water consumption could be important for optimal health.  It’s not unusual for someone to confess they make no effort to drink any water and tend to stick to other beverages especially during the workday; for these people, the suggestion to just start drinking 1-2 quarts of water throughout the day every day is a non-starter.  However, I have had success with getting them to try a one week experiment that doesn’t involve drinking water during the workday. However, this should only be done if you do not have high blood pressure and haven’t been advised by a physician to avoid salt consumption of any kind. Here it is:

One morning when you first wake up and before you have had your morning coffee or tea, combine ¼ teaspoon of sea salt (preferably pink Himalayan or Celtic sea salt, and not table salt) with 4 cups of water and just slightly heat it to make sure the salt is fully dissolved. Go ahead and drink 1 cup of the water and then repeat every 30 minutes until you have consumed all 4 cups (that would take up to 90 minutes). Observe what you notice internally for the rest of the morning.

The usual resistance to doing the above is that the idea of having salt in your water would be gross.  However, I will point out that ¼ teaspoon in a quart is pretty diluted and it’s a subtle flavor that is not very salty at all for most people. If it helps, you can also add a twist of lemon or use carbonated water. The reason sea salt is used rather than table salt is that sea salt contains about eighty mineral elements that the body needs whereas ordinary table salt has been stripped of its companion elements; the sea salt will help the process of hydrating your body with less trips to the bathroom. You may also notice other benefits as well: improved digestion, feeling calmer, improved sleep, better skin, and improved energy, a sense of well-being, and a clearer mind. Obviously, it may a take few days to notice some of these changes but it’s an interesting experiment and the results vary from person to person. If you are not delighted, you can go back to your usual routine and no harm done.  If you do notice some benefit, you could be motivated to continue doing this over time and make it part of your self-care routine and set yourself up for a better day ahead.