H2O: are you drinking enough?
The answer is probably not. According to the National Hydration Council, a startling 89% of the population are not drinking enough to maintain healthy hydration levels. Studies further showed that:
- 20% of men drink no water at all throughout the day, compared to the 13% women
- Age is also a significant factor in hydration levels, with a quarter of the population aged 55+ stating they drink no water during the day; this compares with just 7% of people aged 25-34
Having a 'glass half full' approach to life is a philosophy that embodies a positive mindset. But the concept can also be a useful reminder when it comes to ensuring your glass and body are always topped-up with optimal levels of water – something that supports the function of the 100 billion plus neurons found in our brains. Optimising hydration is typically a matter of being mindful enough to consume 2-4 litres of water daily, depending on your activity and genetics – but the benefits can be well worth it, promoting alertness, concentration, calmness, healthy circulation, wellness and potentially even helping to combat the development of some degenerative diseases.
Optimal Hydration & Brain Performance
“A 1.6% loss of body mass in men led to reduced visual vigilance and working memory and a greater feeling of fatigue and anxiety....”
While factors such as age and genetics influence water levels in the body, typically 50% to 70% of one's body mass is water. In essence – it's critical for human life. Scientists have found that the brain has specific regions dedicated to water balance, with neurons triggering thirst sensations in an attempt to optimise cellular hydration.
A study with soldiers found that dehydration levels of 2% or more, led to a reduction in short-term memory, numeric capacity and attention – while countless studies have also reported impaired mood and subjective feelings, tension, anger, confusion and fatigue. While it's possible for chronic dehydration to affect anyone, especially those who exercise intensely, a 2% loss of hydration is still a lot and not something most people are likely to experience on a daily basis. However, other research has found similar effects of milder dehydration, which is usually considered to be a 1-2% loss of hydration status. For example, when researchers elicited dehydration via exercise, a 1.6% loss of body mass in men led to reduced visual vigilance and working memory and a greater feeling of fatigue and anxiety. Similarly, a 1.4% loss of body mass in women, reduced feelings of vigour, increased fatigue, elicited headaches, disturbed mood and made concentrating during cognitive tasks more difficult. Since mild dehydration is something that can result simply from a lack of fluid intake and may be influenced by a busy lifestyle, air conditioning, heating, exercise and stress, mindfully hydrating can improve your quality of life, wellness and work performance.
Benefits of Optimal Hydration
The mechanics of hydration – how to get healthier neurons?
Science is starting to unravel precisely why dehydration and hydration have such a profound impact on our brains and how we feel and interact with life. Brain imaging has found that dehydration increases neural activity during mentally taxing tasks – suggesting that the brain has to work harder to process information. As a result, ensuring you're well hydrated is likely to enhance your mental edge and reduce stress and strain. In the long-term, scientists suggest that a well-hydrated brain may help to combat mental decline and the development of neurological diseases. Indeed, acute dehydration shrinks the brain, mimicking the loss of cerebral volume witnessed in conditions such as Alzheimer’s.
“Dehydration increases neural activity during mentally taxing tasks – suggesting that the brain has to work harder to process information....”
While optimal hydration is likely to be personal to 'you', depending on your current lifestyle and fluid intake, several studies hint that a moderate increase of 500-1000ml a day enhances subjective quality of life. According to other research, quenching thirst can also enhance general mental speed by as much as 14%, thanks to the almost instantaneous stress relieving impact on brain neurons. The potential benefits of optimal hydration for the cardiovascular system also shouldn't be overlooked – good hydration helps to prevent sluggish blood and keep the heart well hydrated.
Next Level Hydration – Try the Power of Plants
It's easy to just think that a glass of water is the best, even the only way to hydrate, but research suggests that super-food smoothies and eating whole fruits and vegetables may be a superior way to hydrate cells and win the day with the best version of yourself. Indeed, researchers at the University of Aberdeen Medical School found that the natural mineral salts and nutrients in fruit and vegetables may help cells to re-hydrate better than plain water.
“Fruits and vegetables may be a superior way to hydrate cells and win the day with the best version of yourself.”
For example, a snack of cucumber and celery has a very high-water content, but contains a hydrating matrix of calcium, magnesium, phosphorus and iron zinc. This is something echoed by experts at the University of Naples, who found that two biochemicals in plants (Lutein and Zeaxanthin), help increase cellular hydration – try watermelon and papaya for breakfast or as a snack. Some experts recommend squeezing lemon juice or a pinch of Himalayan salt into water to aid hydration.
10 plant foods with over 90% water:
3 Coconut water
Optimising Hydration – How Much is Optimal?
Despite the clear evidence that optimal hydration is good for health, energy levels and mental performance, defining your ideal fluid intake comes down to common sense and some 'biofeedback' to monitor your wellness and adjust your intake accordingly. Fundamentally, the old adage of 'eight glasses of water a day' (around 2l) is a sensible water intake that's likely to provide a good foundation for hydration – something still recommended by the NHS. However, exercise, a busy lifestyle, air conditioning, caffeine and alcohol, central heating, stress and your personal 'DNA' can all affect fluid needs. Typically, paying attention to thirst and responding to internal wisdom is often the best guidance system. However, age can reduce thirst sensations, and it's also easy to become conditioned to ignore your body's cry for water. So, if you're not consuming around two litres daily, the chances are your hydration level isn't optimal. Most experts recommend consuming 2-4l a day, from water and food combined. Unless you're involved in endurance sport, it's not recommended to exceed this level of water intake, since little research suggests it's beneficial, and taken to extremes, it can have adverse side effects.
Optimising fluid intake supports all-round health and vitality, while ensuring your 100 billion plus neurons are bathed in the fluid they need for optimal performance.
Armstrong, L. et al., 2012. Mild dehydration affects mood in healthy young women. Published: J Nutr.
Becker, A. et al., 2017. From Thirst to Satiety: The Anterior Mid-Cingulate Cortex and Right Posterior Insula Indicate Dynamic Changes in Incentive Value. Published: Front. Hum. Neurosci.
Chan, J. 2002. Water, Other Fluids, and Fatal Coronary Heart Disease: The Adventist Health Study. Published: American Journal of Epidemiology.
Ganio, M. et al., 2011. Mild dehydration impairs cognitive performance and mood of men. Published: Br J Nutr.
Gopinathan, P. et al.. 1988. Role of dehydration in heat stress-induced variations in mental performance. Published: Arch Environ Health.
Kempton, M. et al., 2011. Dehydration affects brain structure and function in healthy adolescents. Published: Hum Brain Mapp.
Spigt, M. et al., 2005. Increasing the daily water intake for the prophylactic treatment of headache: a pilot trial. Published: Eur J Neurol.