Grounding: What Science Says About Touching the Earth

For most of human history, people were in direct contact with the ground every day. They walked barefoot or in leather soles, slept on the earth, and worked the soil with their hands. Modern life changed that within a few generations. Rubber and plastic soles, raised beds and multi-storey buildings now keep most people electrically separated from the Earth's surface almost all of the time.

Grounding, also called earthing, means restoring that contact. In practice it is one of two things:

• Outdoors: bare skin touching a natural conductive surface such as grass, soil, sand, the sea shore or unsealed stone.
• Indoors: sitting or sleeping on a conductive mat, sheet or patch connected by a wire to the ground (earth) port of a wall outlet or to a rod pushed into the soil.

A growing body of research suggests this simple contact changes measurable things in the body: markers of inflammation, stress hormones, heart rhythm, blood flow and sleep. The evidence is still early, and this article separates what has been measured from what is still a hypothesis.

The physics: the Earth as a reservoir of electrons

The Earth's surface carries a negative electric charge. It is maintained by the global atmospheric electrical circuit: thousands of thunderstorms active around the planet at any moment keep pumping negative charge down to the ground, while the upper atmosphere stays positively charged. In fair weather this creates a vertical electric field of roughly 100 volts per metre above open ground.

The human body is a good electrical conductor. It is mostly salt water. When skin touches the ground, the body comes to the same electrical potential as the Earth. Grounding researchers describe the Earth as "a virtually unlimited storehouse of accessible electrons" that can then move into the body (Oschman, Chevalier & Brown, 2015).

There is a second, well-documented effect. Indoors, the body picks up a small voltage from the alternating electric fields around household wiring and devices. Grounding drains that induced voltage away. In a 2017 study of 26 premature babies in a neonatal intensive care unit, grounding lowered the infants' skin voltage by about 95% (Passi et al., 2017).

What happens next is where research moves from physics to physiology, and from measurement to hypothesis.

Inflammation: the electron hypothesis

Inflammation is the body's repair response, and it is necessary. When tissue is injured, white blood cells called neutrophils arrive and release an "oxidative burst" of reactive oxygen species (ROS), commonly called free radicals. ROS destroy bacteria and break down damaged cells.

The trouble is collateral damage. A free radical is a molecule with an unpaired electron, so it takes an electron from whatever is nearby, including healthy cells. Those cells are then damaged in turn, which attracts more immune cells and more ROS. The body also seals the injured area with what researchers call an "inflammatory barricade". It keeps pathogens in, but it can also keep antioxidants out. The result can be incomplete repair and what the authors describe as "a vicious inflammatory cycle": the path from short-term to chronic, low-grade inflammation.

The central hypothesis of the 2015 review in the Journal of Inflammation Research is that electrons from the Earth act as natural antioxidants. According to the authors, they travel through the living matrix: the continuous network of collagen and connective tissue (the extracellular matrix) that surrounds every cell and reaches into every organ. Collagen has semiconducting properties, so this network could carry electrons to sites of injury and neutralize ROS before they damage healthy tissue. In the authors' words, the matrix "appears to serve as one of our primary antioxidant defense systems", one that needs "occasional recharging by conductive contact with the Earth's surface".

This mechanism is plausible but has not been directly demonstrated in people. What has been measured are changes in blood markers and symptoms.

The muscle soreness study

In a pilot study, eight healthy adults performed intense eccentric exercise designed to cause delayed onset muscle soreness (DOMS). Four were grounded during rest and sleep, four were not (Brown, Chevalier & Hill, 2010). Over the following three days:

• white blood cell and neutrophil counts were consistently lower in the grounded group
• creatine kinase, a marker of muscle damage, stayed higher in the ungrounded group
• grounded participants reported less pain and tolerated more pressure on the sore muscle

The inflammatory markers and the pain scores moved in the same direction at the same time, which suggests a physiological effect rather than only a change in perception. With four people per group, though, it remains a pilot result.

Wound healing and chronic pain: case reports

Some of the most striking observations in the 2015 review are individual case reports. They are not controlled trials, but they show what researchers and clinicians have observed.

• A chronic diabetic wound. An 84-year-old woman with diabetes had an open foot wound for eight months that had not responded to treatment at a specialized wound center. After one week of daily grounding with a conductive patch, she reported about 80% less pain. After two weeks she was pain-free and the wound showed marked healing.
• An acute injury. A cyclist in the Tour de France cut his leg on a chain wheel. Grounding patches were applied immediately, and by the next day redness, swelling and pain were minimal.
• Infrared imaging. In 20 cases documented with medical thermal imaging, which shows inflammation as heat, painful areas cooled visibly after grounding. In some cases this began within 30 minutes.

The review also reports that people with lupus and other autoimmune conditions repeatedly describe less pain when grounded. This is an observation, not yet a tested treatment.

The nervous system, stress and sleep

The most consistent finding across grounding studies is a shift in the autonomic nervous system: away from the sympathetic "fight or flight" state and toward the parasympathetic "rest and digest" state.

Heart rate variability (HRV) is the natural variation in time between heartbeats. Higher HRV generally reflects stronger vagal (parasympathetic) activity and better capacity to recover from stress. In the 2017 study of 26 premature infants, vagal tone measured through HRV rose by 67% while the babies were grounded and returned to its earlier level once grounding stopped (Passi et al., 2017). Newborns cannot be influenced by expectation, which makes this result especially interesting.

Cortisol, the main stress hormone, normally peaks in the morning and falls at night. In a study by Ghaly and Teplitz (2004), 12 people with pain and sleep problems slept on grounded mattress pads for eight weeks. Their disrupted day-night cortisol rhythm moved toward a normal pattern, and most reported better sleep and less pain and stress.

A small randomized trial with 16 massage therapists, a profession with high rates of musculoskeletal pain, found improvements in physical function and energy and decreases in fatigue, depressed mood and pain during four weeks of grounding. Several of these improvements were still present one month later (Chevalier et al., 2019).

Blood and metabolism

Red blood cells carry a negative surface charge, measured as zeta potential. The stronger that charge, the more the cells repel each other instead of clumping together, and the more easily blood flows. In a study of 10 healthy adults grounded for two hours, zeta potential increased in every sample, on average by a factor of 2.7, and red blood cell clumping decreased (Chevalier et al., 2013). Because high blood viscosity is a recognized cardiovascular risk factor, the authors suggest this may be relevant for heart health.

Polish researchers Karol and Paweł Sokal ran a series of experiments with grounding through copper conductors (Sokal & Sokal, 2011). Among their findings: in 12 people with diabetes, fasting blood glucose fell from an average of 10.6 to 7.4 mmol/L over 72 hours of grounding. They also recorded changes in blood electrolytes, calcium and phosphate balance, and thyroid hormones. These results have not yet been independently replicated in larger studies.

One body, one system

What makes grounding interesting from a holistic point of view is how many systems it seems to touch at once: inflammation, immunity, the nervous system, hormones, blood flow and sleep. That is not a coincidence. These systems are deeply interconnected. Chronic inflammation disturbs sleep. Poor sleep raises cortisol. High cortisol weakens immune regulation and slows healing. A single upstream change in the body's electrical environment or stress state can ripple through all of them.

The living matrix described by Oschman and colleagues is a fitting image of this: one continuous web of connective tissue linking every cell and organ, carrying both mechanical and electrical signals. Whether or not every detail of the electron hypothesis holds, it reflects a principle that integrative medicine increasingly recognizes: the body works as a whole, not as a collection of separate parts.

Grounding outdoors also brings other well-studied benefits with it. Time in nature lowers stress and improves mood. Morning daylight helps set the circadian rhythm that governs sleep and cortisol. Walking barefoot stimulates the many sensory receptors in the soles of the feet and engages small foot muscles. And standing on the earth with attention on the body is, in effect, a mindfulness practice that slows breathing and calms the nervous system. For the person practicing it, these effects add up. For researchers, they are a reason to separate the electrical effect from everything else, which is why many studies use indoor grounding systems with sham (disconnected) controls.

How strong is the evidence?

Grounding research is promising but young. Most studies are small, few are fully blinded, and several key authors disclose financial ties to companies that make grounding products. The 2015 review states that its authors work as contractors for EarthFx Inc., which sponsors grounding research, and that two of them own shares. Critics, including neurologist Steven Novella, argue that the physical premise is overstated and that small studies with many outcomes are prone to chance findings.

• Lower body voltage indoors. Skin voltage drops by about 95% when grounded. Evidence: strong, consistent physics.
• Calmer nervous system. Higher heart rate variability and vagal tone, including in premature infants. Evidence: moderate, several small studies.
• Better sleep and a normal cortisol rhythm. Cortisol rhythm and sleep improved over eight weeks. Evidence: preliminary, small studies.
• Less pain and inflammation. Lower inflammation markers and pain after exercise, plus case reports. Evidence: preliminary, pilot studies.
• Better blood flow. Higher red blood cell charge (zeta potential) after two hours. Evidence: preliminary, one small study.
• Blood sugar and hormones. Changes in glucose, electrolytes and thyroid hormones. Evidence: preliminary, not yet replicated.
• Electrons as antioxidants through the living matrix. Not directly measured in humans. Evidence: hypothesis.

The honest summary: grounding is low-cost, low-risk, and supported by a consistent pattern of early findings. Larger independent trials are needed before it can be called a proven treatment for any disease.

How to practice grounding

1. Choose a conductive surface. Moist grass, soil, wet sand and the sea shore conduct best. Unsealed stone and concrete conduct somewhat. Asphalt, wood, tar, vinyl and rubber do not.
2. Make skin contact. Bare feet are the simplest way. Sitting or lying on the ground, gardening without gloves or placing your hands on the soil also work.
3. Give it time. Studies have used sessions from about 30 to 40 minutes up to a full night of sleep. A practical starting point is 20 to 30 minutes a day.
4. Make it a habit. Effects seen in studies, such as cortisol rhythm and sleep, appeared over weeks of regular grounding, not after a single session.
5. Ground indoors if you can't go outside. Conductive mats, sheets and patches connected to the ground port of an outlet are what most studies used. Check that the outlet is properly earthed and choose products with a built-in safety resistor.
6. Pay attention. Leave the phone behind, breathe slowly and notice your body. This adds the benefits of mindful time in nature to the electrical contact.

Safety

• Never ground outdoors or use an indoor grounding system during a thunderstorm.
• People taking blood-thinning medication should talk to their doctor first, since grounding may affect blood viscosity.
• People taking medication for diabetes, thyroid conditions or blood pressure should monitor their values, because some studies suggest grounding may influence them.
• Grounding supports the body's own regulation. It does not replace diagnosis or treatment of a medical condition.

Sources

1. Oschman JL, Chevalier G, Brown R. The effects of grounding (earthing) on inflammation, the immune response, wound healing, and prevention and treatment of chronic inflammatory and autoimmune diseases. Journal of Inflammation Research. 2015;8:83–96.
2. Passi R, Doheny KK, Gordin Y, Hinssen H, Palmer C. Electrical grounding improves vagal tone in preterm infants. Neonatology. 2017;112(2):187–192.
3. Chevalier G, Patel S, Weiss L, Chopra D, Mills PJ. The effects of grounding (earthing) on bodyworkers' pain and overall quality of life: a randomized controlled trial. Explore. 2019;15(3).
4. Chevalier G, Sinatra ST, Oschman JL, Delany RM. Earthing (grounding) the human body reduces blood viscosity: a major factor in cardiovascular disease. Journal of Alternative and Complementary Medicine. 2013;19(2):102–110.
5. Sokal K, Sokal P. Earthing the human body influences physiologic processes. Journal of Alternative and Complementary Medicine. 2011;17(4):301–308.
6. Ghaly M, Teplitz D. The biologic effects of grounding the human body during sleep as measured by cortisol levels and subjective reporting of sleep, pain, and stress. Journal of Alternative and Complementary Medicine. 2004;10(5):767–776.
7. Brown R, Chevalier G, Hill M. Pilot study on the effect of grounding on delayed-onset muscle soreness. Journal of Alternative and Complementary Medicine. 2010;16(3):265–273.
8. Novella S. Earthing update. Science-Based Medicine. February 8, 2023.