A study published in The Journal of Applied Physiology has found an unexpected link between poor hydration and spikes in the bone-damaging stress hormone cortisol.
We'll examine the study’s details, and you'll learn how much water you should drink to prevent cortisol spikes. Then, we'll review how cortisol affects bone health so you can see how this research relates to your bones.
Adequate hydration has always been one of the Save Institute's recommendations for protecting your bones, and this new research supports it and helps explain the mechanism behind its benefits.
Hydration Status Influences Cortisol Reactivity
A study published in September 2025 found an association between hydration and social stress-induced cortisol spikes.
Researchers enrolled 16 participants with habitual low fluid intake and 16 with high intake. The low intake group consumed roughly 1.3 liters of water per day, while the high intake group consumed an average of 4.4 liters daily.
After seven days of monitored fluid intake, each participant completed the Trier Social Stress Test. Researchers analyzed saliva samples collected before, during, and after the stress test to measure cortisol. Participants wore heart-rate monitors and completed questionnaires assessing anxiety and physiological responses.
The test caused similar increases in anxiety and heart rate in both groups. However, salivary cortisol levels rose significantly only in the low-hydration group.
Cortisol reactivity to acute psychosocial stress is greater in adults with low fluid intake and suboptimal hydration status. Participants who typically drank less than one and a half liters of fluid per day experienced a roughly 55 percent stronger cortisol response than those who drank closer to four liters.
Synopsis
A study found that participants with habitual low fluid intake (less than 1.5 liters per day) and suboptimal hydration had higher cortisol reactivity to acute psychosocial stress.
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How Dehydration Triggers Cortisol Release And How To Prevent It
The hormone arginine vasopressin (AVP) helps the body preserve water when reserves dwindle. That's an essential function; however, it also triggers cortisol release.
When you're underhydrated, the system that maintains fluid balance also heightens cortisol responses to stressors. That makes you prone to a larger cortisol spike in a challenging situation.
Higher cortisol reactivity to acute stress is linked to poorer long-term health outcomes. The link between hydration and cortisol reactivity helps to explain why habitual low fluid intake and under-hydration are also related to poor long-term health.
Chronic elevated cortisol, a condition known as adrenal hypercortisolism or Cushing's syndrome, can trigger a cascade of health problems, including obesity, diabetes, high blood pressure, cardiovascular disease, mood disorders, cognitive impairment, muscle weakness, bone loss, and thin, fragile skin.
U.S. and European guidelines recommend that adult men consume two-and-a-half liters of water per day and women consume two liters per day from beverages and food combined.
The high intake group often exceeded these amounts (sometimes doubling them), but the low intake group fell below the recommendations.
Synopsis
Dehydration activates the hormone arginine vasopressin (AVP), which helps the body to preserve water but also triggers the release of the stress hormone cortisol. When you're underhydrated, this increases your cortisol response to stressors. Higher cortisol reactivity to acute stress is linked to worse long-term health outcomes.
Cortisol And Bone Health
Chronically elevated cortisol levels promote bone loss over time.
Cortisol is catabolic, meaning it breaks down compounds into smaller parts, including proteins in muscle mass. When cortisol levels are too high for too long, this process can cause significant muscle loss, leading to sarcopenia.
Cortisol not only degrades existing muscle but also impairs muscle repair. That repair process, called muscle recovery, is how we build new muscle tissue after exercise.
This directly affects bone health because muscle contractions during weight-bearing exercise are a primary stimulus for new bone formation. The force muscles apply to bone during weight-bearing exercise stimulates new bone formation. Sarcopenia not only threatens strength and physical function, but it also depletes your ability to maintain and build bone mass.
Because of this connection, cortisol can endanger bone health. However, adequate hydration prevents excessive spikes in cortisol during stressful situations, thereby mitigating the threat cortisol poses to your bones.
The Save Institute recommends drinking distilled or reverse osmosis water. Instead of chugging your daily water intake all at once, sip water throughout the day to maintain steady hydration.
Synopsis
Cortisol breaks down the protein that comprises muscle tissue. Chronic high cortisol levels lead to muscle loss and sarcopenia. Bone loss follows muscle loss because the force muscle applies to bone stimulates new bone formation. The Save Institute recommends sipping distilled or reverse osmosis water throughout the day to get adequate hydration.
What This Means To You
Hydration is essential for healthy bones, and new research clarifies why. Sip distilled or reverse-osmosis water throughout the day and aim for at least two liters or 68 ounces per day.
The Osteoporosis Reversal Program explains why healthy habits like hydration can bolster your bone-building progress. In fact, one of the Osteoporosis Reversal Program bonuses included with the program is the Hydration Protocol, which explains how to optimize hydration and reduce exposure to toxic contaminants in drinking water.
By addressing lifestyle factors such as hydration, sleep quality, and physical activity, the Osteoporosis Reversal Program expands your toolkit for reversing and preventing osteoporosis.
Preventing fractures is critical for living the long and independent life you want; use every tool available to achieve that goal and live life to its fullest.
Stronger Bones. Without Drugs. Guaranteed!
The natural and evidence-based program that helps reverse osteoporosis and osteopenia in 12, 6, even 3 months… guaranteed.
References
1 https://journals.physiology.org/doi/full/10.1152/japplphysiol.00408.2025
Interesting article on hydration and cortisol. What is the reason for drinking distilled water or reverse osmosis water, rather than spring water?
Hello
I bought kangen
water machine with the level of clean water to alkaline.
I noticed that level of Carbonate ppm is high .what to do you think Vivian?
Thank you.
Vida, you are correct about the high carbonate levels, because Kangen alkaline water often contains high levels of inorganic minerals like carbonates, which the body can’t use and which can actually be counterproductive for bone health. What matters most is purity, not alkalinity. For that reason, I recommend using a system that removes inorganic minerals and fluoride, such as reverse osmosis or distilled water, instead of adding alkalinity through a machine. You can safely alkalize your body through food, not water. And a few drops of lemon juice will alklaize your water.
We have an RO system in our home and I’m wondering if a daily vitamin is enough to counter calcium and magnesium being removed with this system . Also I worry about no fluoride . Can you address these concerns please . Thank you !
Stephen, reverse osmosis water is actually ideal, because it removes inorganic minerals and fluoride that the body can’t use and that can damage your bones and overall health. Your body gets the organic calcium and magnesium it needs from food and supplements and not from water. Taking a high-quality daily vitamin/mineral formula is the best approach. And no need to worry about fluoride: avoiding it is beneficial for your bones, since fluoride can make them more brittle over time.
Very interesting, thks Vivian, however, inhav been told by a dietician, who took an ultrasound of me, that I hav 2 b careful with drinking 2 much, as I was born with a small bladder – so I drink 5 classes of liquid per day, & also hav soup @ lunch! I am neally 78, but do suffer from low body muscle! I am going 2 keep cold water in my fridge with lemon & a herb, & drink another glass of water, as it is now summer! What do u think Vivian?😆😘
Thanks for sharing your story with us, Joy! Having soup at lunch and drinking a little more water is a great idea. Remember to sip throughout the day, as explained in this article:
https://saveourbones.com/science-says-this-is-the-best-way-to-stay-hydrated/
Wondering why you say reverse osmosis or distilled water. Is filtered water ok?
There are many types of water filters, and their effectiveness varies widely. Most don’t remove fluoride, microplastics, PFAS, or other toxins that can damage health and weaken bones. Reverse osmosis and distilled water do remove these toxins, which is why we recommend them as the safest options for Savers.
I totally relate to this. When I google how much I should be drinking per day for my body weight, it is 12 cups. I definitely feel I have a anxiety and blood pressure spikes at various times and I am not always very good at making sure I drink this much in the hours I am awake. It would be helpful to hear other’s tips and strategies for sipping all day long and not always running to the bathroom, favorite water bottles that are better for the environment, cutting back on caffeine – I do have some oolong, green & white tea some days – but I am sensitive to caffeine. Also, there’s the issue of stopping at a certain hour before bedtime…
Arline, you’ll find the answers to your questions in these articles about hydration:
https://saveourbones.com/science-says-this-is-the-best-way-to-stay-hydrated/
https://saveourbones.com/dehydration-and-osteoporosis/
https://saveourbones.com/solve-these-3-bone-health-issues-by-simply-drinking-more-water/
Stay healthy and active!
I wonder what treatment is best for after effects of spinal fracture in elderly with brittle bones.
Betty, a natural approach is to combine gentle, bone-building lifestyle strategies, not aggressive medical treatments. Instead, following the ORP and its dietary and lifestyle principles focusing on the following:
Pain-free, targeted posture and core-strengthening exercises to support the spine and prevent future fractures.
A pH-balanced, bone-building diet rich in alkalizing foods and Foundation Supplements.
Avoiding bending, twisting, and heavy lifting during healing.
Improving balance and muscle strength to reduce fall risk.
Natural anti-inflammatory strategies (supplements, hydration, rest) to support recovery.
This approach helps reduce pain, improve function, and strengthen bones without the risks of osteoporosis drugs.