We have always been told to drink water and keep ourselves hydrated. But did you know there is also a drinking limit for your body and over drinking water may not be a good thing for your body and your health.

A recent study published in JAMA Network Open explores the conventionally believed thought that drinking more and more water is universally beneficial. The study is conducted by researchers at the University of California, San Francisco (UCSF), and it reviewed the clinical trials to assess whether increasing water intake offers any significant health benefits.

Study's senior author and chair of UCSF's Department of Urology, Dr Benjamin Breyer, said, “For such a ubiquitous and simple intervention, the evidence hasn’t been clear, and the benefits were not well established, so we wanted to take a closer look".

Water Matters, But Why?

Water makes up about 60% of the human body and plays a critical role in essential functions like:

• Regulating body temperature
• Flushing out waste
• Acting as a shock absorber for the brain and spinal cord
• Creating saliva
• Lubricating joints

Dehydration can disrupt these processes, but does drinking more water beyond daily requirements truly enhance health? Here’s what the study found.

Weight Loss

Three studies showed that drinking 51 fl oz (1.5 L) of water daily before meals led to significantly more weight loss among overweight and obese adults over 12 weeks to a year, compared to control groups. However, a separate study found no weight changes when participants consumed 68 fl oz (2 L) daily for six months.

Fasting Blood Glucose

There were mixed results on people with type 2 diabetes. While one study showed a significant reduction in fasting blood glucose levels after participants drank water before meals for 8 weeks, another study found a slight increase in fasting blood glucose after participants drank water in the morning and before bedtime for 12 weeks. Which raised the question that the benefits noted in the first study may have stemmed from decreased food intake or weight loss.

Headaches

Here too, we have conflicting results. One study showed improvement in migraine quality of life and fewer moderate headache days after increasing water intake. However, the results were not statistically significant.

Another trial involving fewer participants reported no notable effect on migraine intensity or frequency.

Bladder Health

We all know that drinking water prevents UTI. In fact, a trial of 140 women prone to recurrent UTIs found that increasing water intake reduced UTI episodes and antibiotic use over a year.

However, there was a small study that found no significant change in urinary bacteria among women who drank more water. Interestingly, reducing fluid intake by 25% helped adults with overactive bladder experience fewer urges and nighttime trips to the bathroom.

Kidney Stones

Here, the evidences supported increased water consumption for reducing kidney stone risks. In one study, healthy adults drinking an additional 68 fl oz (2 L) of water daily had a lower risk of developing kidney stones. Another trial showed a significant drop in kidney stone recurrence over five years among those who increased water intake.

So, what does it really mean?

While drinking more water was associated with clear benefits in areas like weight loss and kidney stone prevention, the evidence for other conditions—such as headaches, bladder health, and diabetes—was less conclusive.

“The amount of rigorous research turned out to be limited, but in some specific areas, there was a statistically significant benefit,” said Dr. Breyer. “There isn’t a one-size-fits-all approach for water consumption," said Dr Breyer.

Long-term exposure to tiny air pollution particles can significantly increase your risk of developing Alzheimer's disease-caused dementia.

Researchers from Emory University, US have found that constant exposure to PM2.5 can affect the brain more directly than scientists have assumed.

They noted: "Alzheimer's disease is the most common form of dementia and a growing public health challenge, especially in aging populations. Our findings suggest that PM2.5 exposure was associated with increased Alzheimer's disease risk, primarily through direct rather than comorbidity-mediated pathways."

The scientists also discovered that those who had suffered a stroke were at a slightly higher risk of developing Alzheimer's disease, suggesting that strokes may make the brain more vulnerable to air pollution.

"The observed effect modification by stroke may reflect an underlying biological vulnerability in cerebrovascular pathways. Stroke-related neurovascular damage can compromise the blood–brain barrier, facilitating the translocation of PM2.5 particles or their associated inflammatory mediators into the brain."

The observational study was released in PLOS Magazine.

When Does The Risk Increase?

A new IIT Delhi study suggests the air quality may be worse than what conventional surface monitoring stations capture.

During a post-winter-haze day in March 2021, the researchers measured the vertical distribution of fine particulate matter at 20-metre intervals from the surface up to 100 meters through drones.

At 100 meters, PM2.5 concentrations were around 160 micrograms per cubic meter which is about 60 percent higher than surface readings on the same days. They also found that humidity levels were also higher by 70 percent, which promoted the concentration of ammonium nitrate and chloride.

Additionally, the study found that PM2.5 levels increased sharply near the top of this shallow layer, leading to higher concentrations at around 100 metres.

Based on these observations, the researchers concluded that residents in 28–30-storey buildings may face higher exposure to pollutants and inorganic material than indicated by ground-based monitors.

They also noted that drone-mounted low-cost sensors are a much more effective tool for studying the lower atmospheric boundary layer to improve air quality monitoring, model evaluation and mitigation strategies in cities such as Delhi.

What Is Alzheimer’s Disease?Alzheimer's disease is one of the most common forms of dementia and mostly affects adults over the age of 65.

About 8.8 million Indians aged 60 and above are estimated to be living with Alzheimer's disease. Over seven million people in the US 65 and older live with the condition and over 100,00 die from it annually.

Alzheimer's disease is believed to be caused by the development of toxic amyloid and beta proteins in the brain, which can accumulate in the brain and damage cells responsible for memory.

Amyloid protein molecules stick together in brain cells, forming clumps called plaques. At the same time, tau proteins twist together in fiber-like strands called tangles. The plaques and tangles block the brain's neurons from sending electrical and chemical signals back and forth.

Over time, this disruption causes permanent damage in the brain that leads to Alzheimer's disease and dementia, causing patients to lose their ability to speak, care for themselves or even respond to the world around them.

While there is no clear cause of Alzheimer's disease, experts believe it can develop due to genetic mutations and lifestyle choices, such as physical inactivity, unhealthy diet and social isolation.

Early symptoms of Alzheimer's disease include forgetting recent events or conversations. Over time, Alzheimer's disease leads to serious memory loss and affects a person's ability to do everyday tasks.

There is no cure for this progressive brain disorder and in advanced stages, loss of brain function can cause dehydration, poor nutrition or infection. These complications can result in death.

Frequently experiencing deep sleep may help prevent the development of brain changes related to Alzheimer's Disease, the most common form of dementia.

Researchers from the University of California, Berkeley, Stanford University, and UC Irvine in the US have found that people experiencing early symptoms of Alzheimer's performed better on memory function tests as they got more deep sleep.

This sign was found to be independent of education and physical activity, two factors, along with social connection, known to contribute to cognitive resilience in older age.

Those with similar Alzheimer's-linked changes who failed to get as much deep sleep did not do as well on the same tests. By comparison, sleep made little difference to those individuals with few Alzheimer's-related deposits.

The results imply that a frequently being able to sleep deeply frequently could help support the memory decline that sets in as dementia begins to take hold.

UC Berkeley neuroscientist Matthew Walker said of the results: "Think of deep sleep almost like a life raft that keeps memory afloat, rather than memory getting dragged down by the weight of Alzheimer's disease pathology.

"This is especially exciting because we can do something about it. There are ways we can improve sleep, even in older adults."

Previous research has also shown that poor sleep is both a risk factor for and a symptom of Alzheimer's disease, making it tricky for scientists to detect how sleep is linked to neurological damage.

What Is Alzheimer’s Disease?Alzheimer's disease is one of the most common forms of dementia and mostly affects adults over the age of 65.

About 8.8 million Indians aged 60 and above are estimated to be living with Alzheimer's disease. Over seven million people in the US 65 and older live with the condition and over 100,00 die from it annually.

Alzheimer's disease is believed to be caused by the development of toxic amyloid and beta proteins in the brain, which can accumulate in the brain and damage cells responsible for memory.

Amyloid protein molecules stick together in brain cells, forming clumps called plaques. At the same time, tau proteins twist together in fiber-like strands called tangles. The plaques and tangles block the brain's neurons from sending electrical and chemical signals back and forth.

Over time, this disruption causes permanent damage in the brain that leads to Alzheimer's disease and dementia, causing patients to lose their ability to speak, care for themselves or even respond to the world around them.

While there is no clear cause of Alzheimer's disease, experts believe it can develop due to genetic mutations and lifestyle choices, such as physical inactivity, unhealthy diet and social isolation.

Early symptoms of Alzheimer's disease include forgetting recent events or conversations. Over time, Alzheimer's disease leads to serious memory loss and affects a person's ability to do everyday tasks.

There is no cure for this progressive brain disorder and in advanced stages, loss of brain function can cause dehydration, poor nutrition or infection. These complications can result in death.

Can You Detect Alzheimer's Early On?

The blood test, known as Lumipulse, can detect amyloid plaques associated with Alzheimer’s disease and has proven to be a “less invasive option” that “reduces reliance on PET scans and increases diagnosis accessibility.”

FDA Commissioner Martin A. Makary said of the landmark decision, "Alzheimer’s disease impacts too many people, more than breast cancer and prostate cancer combined.

"Knowing that 10 percent of people aged 65 and older have Alzheimer's, and that by 2050 that number is expected to double, I am hopeful that new medical products such as this one will help patients."

It remains unclear when this test will be available for commercial use across the world.

Think you aged overnight or have you been seeing more signs of aging recently?

According to an August 2024 Nature Ageing study on molecular changes associated with ageing, humans age significantly twice in their life, once at an average age of 44 and the other at around age 60.

Geneticist Michael Snyder of Stanford University explained: "We're not just changing gradually over time; there are some really dramatic changes. It turns out the mid-40s is a time of dramatic change, as is the early 60s. And that's true no matter what class of molecules you look at."

The study found that about 81 percent of all the molecules they studied showed changes during one or both of these stages. Changes peaked in the mid-40s, and again in the early 60s, with slightly different profiles.

The mid-40s peak showed changes in molecules related to the metabolism of lipids, caffeine, and alcohol, as well as cardiovascular disease, and dysfunctions in skin and muscle.

The early 60s peak was associated with carbohydrate and caffeine metabolism, cardiovascular disease, skin and muscle, immune regulation, and kidney function.

However, the study authors noted that more granual research was needed to understand how the ageing process works at these peak ages.

Which Gender Ages Faster?

Mariana Rodrigues, a PhD student at NYU School of Global Public Health and the first author of the study, said: "Our research suggests that subjective experiences may be driving objective measures of aging. Aging-related anxiety is not merely a psychological concern, but may leave a mark on the body with real health consequences."

"We know from previous research that anxiety, depression, and mental health in general are associated with a number of physical health outcomes, but until now researchers haven’t focused on whether there is a correlation between worrying about aging and the process of aging itself.

“Women in midlife may also be multiple in roles, including caring for their aging parents. As they see older family members grow older and become sick, they may worry about whether the same thing will happen to them".

After analyzing data from 726 women, the researchers while worrying about declining health, had the strongest associations with biological aging, anxiety about declining attractiveness and fertility were not significantly associated with it.

They theorized that this may be because research shows that health-related concerns are more common and persist over time, while worries about beauty and reproductive health may fade with age.

“Aging is a universal experience,” said Rodrigues. “We need to start a discourse about how we as a society—through our norms, structural factors, and interpersonal relationships—address the challenges of aging.”

Warning Signs You May Be Aging Faster

• Constant fatigue and loss of energy: Everyday tasks feel harder, and the body tires more quickly than before.
• Skin and hair changes: Reduced collagen and keratin production leads to sagging, wrinkles, and thinning or loss of hair.
• Cognitive decline: Memory lapses, difficulty in planning, and problems with calculations may point to aging-related changes in the brain as grey matter begins to shrink.
• Chronic conditions: Lifestyle diseases like diabetes and hypertension are often tied to aging, linked to reduced insulin production and thicker, slower blood flow.