From controlling body temperature and flushing out toxins, adequate hydration plays a vital role in our general health and well-being, water is a life essential. However, while dehydration garners significant attention, overhydration, or drinking excessive amounts of water, is a condition that can have serious and sometimes fatal consequences.

Although it may sound bizarre since drinking water is said to be the solution for most health related problems it is important to recognize how much water is considered "too much" or the risks involved with being overhydrated can maintain a healthy balance.

What Is Water Intoxication?

Water intoxication, also termed hyperhydration, water poisoning or water toxemia, develops when an individual drinks much more water than the kidney can excrete. The main function of the kidneys in the human body is the processing and excretion of excess water. However, the human kidneys can process only up to 0.8 to 1.0 liters of water at a time. Drinking an amount that exceeds this may overwhelm the kidneys and put the electrolyte balance out of sync in the human body.

Electrolytes, especially sodium, are essential in maintaining fluid balance within and outside cells. Hyponatremia is the condition when sodium levels fall below 135 mmol/L, resulting from excessive water intake. This causes water to shift into cells, swelling them. In the brain, this can cause severe complications, including coma or even death.

Symptoms of Water Intoxication

The symptoms of water intoxication vary from mild to severe. Early symptoms are often similar to dehydration, which makes self-diagnosis challenging. Common symptoms include:

• Headaches
• Nausea and vomiting
• Muscle cramps or weakness
• Fatigue or drowsiness
• Confusion and disorientation

In more serious cases, water intoxication can cause seizures, loss of consciousness, or swelling in the brain. These complications can be fatal if left untreated.

A notable case occurred in 2007 when a woman participating in a water-drinking contest tragically died after consuming nearly two gallons of water in under two hours. More recently, actress Brooke Shields experienced a grand mal seizure attributed to excessive water consumption.

Causes of Water Intoxication

Water intoxication is rare, but certain scenarios can increase the risk:

1. Sporting Events and Endurance Training

These endurance athletes are prone to water intoxication, especially if they drink large amounts of water without replacing lost electrolytes. Hyponatremia usually happens during long races or marathons as individuals mistake fatigue and muscle cramps for dehydration and continue drinking water in excess.

2. Military Training

Overhydration among military personnel is usually due to severe physical activity in extreme environmental conditions. The total number of hyponatremia cases documented from 2007 through 2022 for the active duty in the United States exceeds 1,600, with a note to this problem on exertion-related overhydration.

3. Mental Health Conditions

Compulsive water drinking, known as psychogenic polydipsia, is linked with some mental illnesses such as schizophrenia and psychosis. People with these conditions tend to drink too much water, causing a hazardous electrolyte imbalance.

4. Drug Abuse

Drugs such as MDMA (ecstasy) raise the body temperature and make people thirsty, and at times, some people tend to drink excess water at events like music festivals. MDMA also leads to urine retention, thus exacerbating the dangers of water intoxication.

How Much Water Is Too Much?

The exact amount of water that causes intoxication varies from one person to another. However, drinking more than 1 liter of water per hour for several hours raises the risk. For healthy individuals, the risk of overhydration is low unless taking part in extreme physical activity or ignoring thirst cues.

Certain medical conditions, such as kidney or liver disorders, can impair the body's ability to process fluids, and even moderate water intake may be harmful. Similarly, certain medications, such as diuretics and antipsychotics, can affect the perception of thirst or fluid regulation.

How Much Water Is Enough?

The widely touted recommendation of eight 8-ounce glasses of water per day has little basis in fact. According to the National Academy of Medicine, a daily total fluid intake is about 15 cups (3.7 liters) for males and 11 cups (2.7 liters) for females, from beverage sources and from food. Usually, about 20 percent of daily hydration comes from foods such as fruits and vegetables.

A better rule of thumb is to listen to your body and drink water based on thirst. Use the color of your urine as an indicator:

• Light yellow urine indicates proper hydration.
• Dark yellow urine may indicate dehydration.

Older adults, whose thirst mechanisms may decline with age, should be proactive about maintaining hydration, especially during illness or hot weather.

Water Intoxication vs. Dehydration

The symptoms of water intoxication—such as headaches, fatigue, and muscle weakness—are similar to those of dehydration. If you are unsure which condition you are experiencing, seek medical attention immediately rather than self-treating with more water.

Preventing Water Intoxication

To avoid the dangers of overhydration:

• Drink water gradually throughout the day rather than consuming large amounts at once.
• Replace lost electrolytes post high-intensity exercise or heavy sweating.
• Consider using sports drinks or salty snacks to help replenish sodium.
• Keep track of fluid consumption during long-duration activities, and do not consume more water than the body is losing in terms of electrolytes.
• If on medications or have specific medical conditions, check with your doctor regarding the safety of drinking water.

For signs of severe water intoxication-including confusion, drowsiness, seizures, and loss of consciousness-customer is advised to seek medical assistance immediately. In the meanwhile, a salty snack would help to temporarily correct low sodium levels.

Hydration is important to health, but overhydration can be a serious risk; the secret is in finding a balance. Drink enough water to satisfy your body, but not so much that it overwhelms your system. Remember, water is life, but moderation keeps it that way.

Hyponatremia (low sodium level in the blood). National Kidney Foundation. 2023.

Water Toxicity. NIH. 2023

Exercise-Associated Hyponatremia: 2017 Update. Front Med (Lausanne). 2017

Update: Exertional Hyponatremia Among Active Component Members of the U.S. Armed Forces, 2007–2022

Obesity during the 20s and 30s can fuel the risk of many lifestyle disorders like type 2 diabetes, cardiovascular diseases, metabolic syndrome, non-alcoholic fatty liver disease, sleep apnea and many others.

But according to a large study published in Annals of Internal Medicine, obesity could also increase the risk of developing cancer before midlife. The study identified higher chances of thyroid, endometrial and ovarian cancers.

How Was The Study Conducted?

Researchers examined health records of 6,313,338 adults in South Korea, aged between 20 to 39 years, who had no previous history of cancer.

Participants were followed for an average of 11.2 years to study the relationship between body weight and cancer risk.

During the follow-up period, 151,893 cancer cases were recorded. The findings showed that cancer risk increased in people with higher body mass index (BMI).

The researchers found that the 10-year total incidence of cancer was 1.84% among people with normal body weight. This increased to 2.24% among those with class I obesity and 2.62% among those with class II obesity.

In other words, the 10-year cancer incidence was approximately 0.78 percentage points higher among people with class II obesity than among those with normal weight.

The researchers also found that people with abdominal obesity were at higher cancer risk than those who didn’t have.

Among people with class I obesity, the 10-year cancer incidence was 2.45% in those with abdominal obesity, compared with 2.13% in those without it.

“Because abdominal obesity may be an important indicator for distinguishing cancer risk, it is important to manage waist circumference along with weight from a young age,” the authors wrote.

Also read: High-Fibre Diet Outperforms Metformin In Blood Sugar Control And Weight Loss, Study Finds

Three Cancers Linked To Early Adulthood Obesity

The study identified particularly strong associations between obesity and cancers involving the thyroid and female reproductive system.

Thyroid cancer: Excess body weight has previously been linked with changes in metabolic and hormonal changes that may affect thyroid cancer development.

Endometrial cancer: Obesity can increase oestrogen levels because fat tissue produces this hormone. Prolonged exposure to excess oestrogen can stimulate the growth of the uterine lining and increase the risk of endometrial cancer.

Ovarian cancer: The relationship between obesity and ovarian cancer is complex and may involve inflammation, insulin resistance and hormonal changes.

Also read: Warren Buffett Says He Hasn't Drunk Water In 48 Years: What Happens If You Replace It With Coke?

Obesity & Cancer Risk

Obesity causes several biological changes that may contribute to cancer development. One of them is chronic inflammation.

Excess fat tissue can fuel inflammation that may create an favourable environment for abnormal cell growth.

Obesity can also lead to insulin resistance, in which the body’s cells respond less effectively to insulin. This can cause higher insulin levels, which may fuel cell growth and proliferation.

Hormonal changes are also a factor. Fat tissue produces oestrogen, and higher levels of this hormone have been linked with cancers like endometrial and ovarian.

The study authors wrote, "Some cancers have recently become more common even among younger people, and this study confirmed that obesity in young adults is significantly associated with the development of these cancers."

Scientists have discovered a previously unknown mechanism that could explain why high cholesterol diet makes it challenging for the liver to remove bad cholesterol from the bloodstream. Researchers have also identified an experimental drug that blocks this process, offering a new method for treating high cholesterol.

The findings are published in the journal Nature by researchers from the University of California San Diego School of Medicine. Their experiments showed that blocking a specific enzyme called cathepsin A (CTSA) helped retain the liver's ability to clear low-density lipoprotein (LDL), commonly known as bad cholesterol.

In mice, inhibiting this enzyme stabilised LDL receptors in liver cells, reducing LDL cholesterol.

"We've known for a long time that a high-cholesterol diet reduces the liver's ability to clear cholesterol from the blood, but we didn't fully understand why," said senior author Alan Saltiel, professor of medicine at UC San Diego School of Medicine. "This new discovery explains a critical piece of that puzzle."

More About The Experiment

The liver plays a key role in regulating cholesterol levels. It uses LDL receptors located on the surface of liver cells to capture LDL cholesterol from the bloodstream.

When fewer of these receptors are available, the liver becomes less efficient at removing LDL cholesterol, allowing it to increase in the bloodstream. The researchers discovered that consuming high amounts of dietary cholesterol activates a protein called Ral. This increases the activity of CTSA, an enzyme that breaks down LDL receptors.

As these receptors are lost, the liver's ability to clear bad cholesterol declines. When researchers blocked CTSA using a small molecule inhibitor, LDL receptors became more stable and LDL cholesterol levels decreased dramatically in mice.

Also read: Recreational Drugs, Steroids & Birth Control: Expert Explains Why Strokes Are Arriving Decades Earlier

Experimental Drug That Can Help Lower Cholesterol

The discovery has sparked interest as researchers have identified an experimental drug that targets CTSA. The drug was originally developed as a possible treatment option for heart failure. Although its development for that purpose was discontinued for other reasons, it had already completed a Phase 1 clinical trial, which evaluated its safety in humans.

This previous test could help researchers move towards studying its ability as a cholesterol treatment. However, the drug has not yet been shown to lower LDL cholesterol in humans.

"There's still a real need for new cholesterol-lowering options, since some people can't get to safe levels even with the drugs we have now," Saltiel said.

He added, "This new pathway we discovered is completely separate from anything that existing drugs target, so it gives us a new opportunity to fill that gap."

The researchers hope to test the experimental CTSA inhibitor in a Phase 2 clinical trial to determine whether it can safely and effectively lower cholesterol in people. If successful, the approach could offer another option for people who struggle to control LDL cholesterol despite using existing treatments.

Saltiel said, "Luckily, there's an experimental drug sitting on the shelf that's already been shown to be safe in humans."

"We hope to test whether this might be effective by conducting a clinical trial -- which could potentially bring a new treatment option to patients much sooner than would have been expected."

Irritable bowel syndrome (IBS) is often characterised by digestive symptoms like abdominal pain, bloating, constipation and diarrhoea. However, the condition involves more than the digestive system.

A new review published in The Lancet explains how interactions between the gut and brain, changes in the gut microbiome, immune activity and the body's response to pain can contribute to the development of symptoms.

The review, titled Irritable bowel syndrome and related disorders of gut-brain interaction, brings focuses on biological and psychological evidence behind IBS. Researchers describe it as a disorder of gut-brain interaction, in which signals between the digestive system and the central nervous system affect gut function.

The authors also discuss chronic constipation and functional diarrhoea, which belong to the bigger group of disorders related to gut-brain interaction. These conditions may affect an estimated 20% of the global population.

What Is The Gut-Brain Connection In IBS?

Also read: Olympian Ciara Mageean Dies At 34 After Bowel Cancer Battle: Warning Signs In Young Adults

The gut and brain communicate continuously through a complex network that involves the central nervous system, autonomic nervous system, enteric nervous system and hypothalamic-pituitary-adrenal (HPA) axis.

The brain can influence intestinal movement, secretion and sensitivity, while signals from the gut can affect how the brain processes pain and other sensations.

In people with IBS, this communication may become disrupted. The result can be changes in bowel movements, more sensitivity to normal digestive processes and abdominal discomfort.

The authors said, “These central and peripheral mechanisms can act in an integrated way to cause IBS symptoms, via the gut-brain axis.”

For instance, a person with IBS may experience pain or bloating even when the amount of gas or intestinal movement would not cause discomfort in someone without the condition. This is due to a condition called visceral hypersensitivity, in which the nerves supplying the digestive organs become unusually sensitive to internal sensations.

The review explains that changes in both peripheral mechanisms within the gut and central mechanisms involving the brain can contribute to symptoms.

Gut Bacteria And Inflammation May Contribute To IBS

Also read: Can Coffee Trigger Irritable Bowel Syndrome?

The gut microbiome, which consists of microorganisms living in the digestive tract, is another important part of the gut-brain connection.

Changes in the composition and activity of gut bacteria may impact intestinal function, immune responses and communication with the nervous system. The review identifies the following:

• Gut infections: Gastrointestinal infections can trigger IBS symptoms in some people, even after the initial infection has subsided.
• Altered gut microbiome: Changes in intestinal bacteria may affect digestion, immune activity and gut function.
• Increased intestinal permeability: Changes in the intestinal barrier may allow substances to pass through more easily, potentially contributing to immune activation.
• Low-grade inflammation: Mild inflammation in the intestinal lining and changes in immune function may contribute to symptoms.
• Abnormal gut movement: Changes in gastrointestinal motility can cause food and waste to move through the digestive tract too quickly or too slowly.
• Visceral hypersensitivity: Increased sensitivity in the gut can make normal digestive processes feel painful.

Mental Health And IBS

Psychological health is another component of the gut-brain axis. Stress, anxiety and other psychological difficulties can influence how the brain processes pain and communicates with the digestive system.

The HPA axis, which helps regulate the body's response to stress, plays a role in this process . Changes in stress levels can affect gut movement, secretion and sensitivity.

Currently, there is no single biomarker that can diagnose IBS. Doctors assess symptoms, medical history and clinical findings, while using tests to rule out other conditions.

The review highlights that some underlying mechanisms can already be measured through approved tests and questionnaires. These include abnormal bile acid metabolism, accelerated movement of contents through the colon and psychological conditions.