# daily Water Intake Linked to Stress Hormone Levels
Researchers discovered that people who don’t drink enough water react with sharper cortisol spikes during stressful events, explaining why poor hydration is tied to long-term health risks.
Drinking less water daily spikes your stress hormone
study: Habitual fluid intake and hydration status influence cortisol reactivity to acute psychosocial stress. Image credit: PeopleImages/Shutterstock.com
A recent study in the Journal of Applied Physiology examined the impact of hydration status and habitual fluid intake on saliva cortisol reactivity to psychosocial stress. Suboptimal hydration and habitual low fluid intake are associated with greater cortisol reactivity to acute psychosocial stress, which may adversely influence long-term health.## Hydration and cortisol reactivity to stress
Consistently drinking less than the recommended daily amount of water can lead to suboptimal hydration, often shown by darker, more concentrated urine and reduced output. Research has associated habitual low fluid intake with a greater metabolic, renal, and cardiovascular disease risk. Chronic low water intake may increase water-regulating hormones, such as arginine vasopressin (AVP), which can increase the release of the stress hormone cortisol.
It is well known that cortisol spikes during acute stress,but it also follows a daily rythm. When this circadian rhythm is disrupted, or when cortisol responses are exaggerated, it can affect immunity, metabolism, and inflammation. Some research has found higher cortisol levels in people who are suboptimally hydrated and drink less than 1.2 L of fluid per day. However, the exact link between fluid intake, hydration, and cortisol remains uncertain.## About the study
Given the shared pathways between stress hormone cortisol release and whole-body water regulation, this study aimed to verify that individuals with suboptimal hydration and habitual low fluid intake show greater cortisol reactivity to acute psychosocial stress.Eligible participants were non-smokers,healthy,aged 18-35 years,and free from any known immune,cardiovascular,sleep,or metabolic disorders. Individuals were identified as being habitually low or high fluid drinkers, i.e., LOW and HIGH.