Water is essential for life, yet 75 percent of Americans don’t drink enough of it. The worst part is most people are so used to feeling like crap that they don’t know what it feels like to be hydrated. And in attempts to battle the fatigue and brain fog that comes with dehydration, they adopt bad habits like eating refined carbs and sugar or overdoing it on caffeine—habits that wind up dehydrating them even more and can lead to more health problems down the road. The Effects of a Dehydrated BrainWe need water to support the shape and function of our cells. When our cells aren’t getting the water they need, they start to shrivel up and lose their ability to function optimally. And it’s not just the cells in our body; our brain cells are affected too. Studies show that losing just 1-2 percent of your body’s total water mass can cause your brain to shrink, which significantly impairs cognitive function. As a result, your brain has to work harder to perform the same tasks. Over time, chronic dehydration can increase your risk for Alzheimer’s and dementia—but not just because it impairs brain function. Dehydration also promotes protein misfolding and the formation of amyloid plaques inside the brain—the most well-recognized contributor to neurodegenerative disease. We Need Water to Wash Away the WasteYour immune system needs water to wash away the metabolic waste that accumulates during the day, and it’s most active at night while you’re sleeping. Going to bed dehydrated means your immune system doesn’t have the water it needs to do its job correctly. In addition to that, you’re fasting from water all night long, which means your immune system is working with a limited water supply. It’s like trying to mop a dusty floor without water—our immune system can’t wipe away the debris, plaque, and damaged cells. And the more mess that’s left behind, the more damage that starts to accumulate. When you pair a lack of water with poor sleep quality, the immune system has a hard time getting rid of built-up waste, which can eventually form zombie cells and lead to chronic disease. Wake Up and Drink WaterOver 150 million Americans reach for coffee first thing in the morning—a diuretic that depletes us of even more water. Tack on the fact that we’re fasting from water all night while we’re sleeping, and we start the day entering the vicious cycle of dehydration. Start your day off with two big glasses of water before having your morning coffee. Not only will this give your body what it needs to flush out the waste and toxins that accumulate overnight, but it will also give you a hydration buffer to work with for the rest of your day. Many people have trouble with nocturia, a condition where they have to get up and go to the bathroom multiple times throughout the night. To avoid having nocturia disrupt your sleep quality, aim to drink most of your water in the early parts of the day. Create Hydration HabitsThere are a lot of factors that contribute to cognitive decline (refined carbs, a nutrient-poor diet, environmental toxins, and chronic stress, to name a few). Luckily, however, dehydration is in our control and easy to modify. But that’s only if we remember to do it. There are some strategies we can take to improve our hydration habits as well as our body’s capacity to use and hold on to the water we drink: Pay attention to and honor thirst cues (dry mouth, lips, and skin; fatigue). Even though our bodies have ways of telling us they need more water, our modern-day lifestyle is so fast paced that people can go all day without drinking water. Additionally, the thirst receptors in our brains start to lose their sensitivity as we get older, so dehydration cues don’t register as effectively to let us know when it's time for a drink. Because thirst sensations diminish with age, older individuals tend to be more dehydrated. In fact, dehydration is an under-recognized and common cause of hospitalization and death in the elderly. Set hydration reminders. Some ways to trigger you to remember to drink include setting reminders on your phone or purchasing a plastic-free water bottle that has reminders for when it’s time to drink throughout the day. Build and maintain lean muscle mass. How is muscle related to hydration? Muscle is a water reservoir. Compared to fat tissue, which is about 10 percent water, our muscle tissue is made up of about 80 percent water. Aging makes us more susceptible to losing muscle mass.Holding on to water in our muscles gives our body a backup source when availability might be scarce (like when we’re sleeping). Lean muscle mass helps protect against dehydration, makes us stronger, and lowers our risk of age-related bone fractures. Do strength training a few times a week (weightlifting, yoga, or planks) to build up lean muscle mass. Replenish what you lose. Speaking of strength training, we can’t forget to replace the water we lose in our sweat after a tough workout or sauna session or from spending a hot day outside in the sun. You need electrolytes to replenish the sodium, potassium, and magnesium lost in sweat. How much water do you need to achieve hydration? Many factors influence hydration needs: your age, sex, size, and physical activity level; how much you sweat; the climate you live in; etc. You are the best judge of your hydration, but only if you know what it feels like to be properly hydrated. Start with the “8 x 8 rule” (drink eight 8oz glasses of water a day) or drink half your weight in ounces as a baseline; you can personalize it from there. Because aging and dehydration are so closely connected, experts have difficulty pinpointing which one comes first—dehydration or dementia. Regardless, we can take steps to make sure dehydration isn’t negatively impacting our brain function. But we have to make sure we’re making a conscious effort and drinking enough water, especially in the early parts of the day. Wishing you health and happiness, Mark Hyman, MD
