We all must have come across the phase: this is why women live longer than men. These are all over the social media, where men are performing more often than not, some experiments, without gears, just for fun, "in the name of science". The caption reads: this is why women live longer. However, is there really a science to it, other than the fact that women choose to do things more safely?

In the United States, women have a life expectancy of about 80, whereas men have 75. Women outlive men and this holds true regardless of the country women live, the money they make, and other factors. In fact, it is true for most other mammals too.

Dr Dena Dubal, a professor of neurology at the University of California, San Francisco told the New York Times, "It is a very robust phenomenon all over the world, totally conserved in sickness, during famines, during epidemics, even during the times of starvation."

But what are the reasons? These reasons are often more complicated and less established. It is important to note that only because women are outliving men does not mean they are living a better life. In fact, women tend to have shorter health spans, which means the number of healthy years in a person's life is less in women than men, confirmed Bérénice Benayoun, an associate professor at the U.S.C. Leonard Davis School of Gerontology.

As per a 2021 study titled, Sex differences in frailty: Comparisons between humans and preclinical models, found that women are more physically grail than men in old age. They are also more vulnerable, especially after menopause and are at more risk of developing cardiovascular issues and Alzheimer's disease because of age.

The key is in figuring out what makes one sex more resilient or vulnerable.

Genetics

For things which do not find easy explanations, scientists look for their answers in genes. Many research, including a 2020 study titled, The sex with the reduced sex chromosome dies earlier: a comparison across the tree of life, suggests that the XX set of female sex chromosomes may impact longevity. However, there has not been any clarity on how it affects longevity.

Another 2018 study titled, Female XX sex chromosomes increase survival and extend lifespan in aging mice, which was conducted by Dr Dubal's lab, looked at genetically manipulated mice with different combinations of sex chromosomes and reproductive organs. It was found that those with two X chromosomes and ovaries lived longest, followed by mice with two X chromosomes and testes. Mice with XY chromosomes had shorter life spans.

"There was something about the second X chromosome that was protecting the mice from dying earlier in life, even if they had testes. What if there was something on that second X chromosome that was in some ways a sprinkle of the fountain of youth," says Dr Dubal. While scientists have not yet looked at this factor in humans, Dr Dubal suggests that humans have the same hormones and sex chromosomes, and similar reproductive system that could corroborate the similar findings in people.

Hormones

Plenty research has shown that estrogen is responsible for longevity also effect on the immune system. The data also shows that before menopause, the female immune system tends to do better. In fact Dr Benayoun said that males tend to do much worse in response to infection.

Another 2017 study titled, Ages at Menarche and Menopause and Reproductive Lifespan As Predictors of Exceptional Longevity in Women: The Women's Health Initiative, found that women who experienced menopause later in life over the age 50 lived longer than those who experienced it earlier.

Lifestyle and Behavior

There are also disparity in behavioral patterns between men and women. This includes smoking, drinking heavily, which can contribute significantly to mortality. Women also have more "health promoting behavior", believe experts. Women are also more likely to socialize than men and thus it protects them from detrimental effects of social isolation and loneliness. In fact, a 2023 analysis published in Jama Network, titled, Widening Gender Gap in Life Expectancy in the US, 2010-2021, found that women are less likely to die by drug overdose or suicide.

Winters can be especially demanding for many women going through menopause or perimenopause. As the colder months arrive, concerns like dry, irritated skin, unexpected hair fall, and increased joint pain become more common. This rise in symptoms is not caused by cold weather alone. It is largely driven by the way seasonal changes interact with the hormonal transitions of menopause. To understand this better, we spoke to Tamanna Singh, Co-founder of Menoveda and a Certified Menopause Coach, who explained why these changes happen.

What Is Menopause?

Menopause is a natural biological phase when a woman’s menstrual cycles stop permanently, signalling the end of her reproductive years. It is officially diagnosed after 12 consecutive months without a period and usually occurs between the ages of 45 and 55, as the ovaries gradually reduce estrogen production.

The phase leading up to this, called perimenopause, involves fluctuating hormones that can trigger symptoms such as hot flashes, mood changes, and sleep disturbances. Postmenopause refers to the stage after menopause, according to the Mayo Clinic.

How Long Does Menopause Last?

Menopause itself is a single milestone rather than a prolonged phase. Once a woman has gone a full year without a menstrual period, she is considered menopausal. After this point, she enters postmenopause, which continues for the rest of her life.

Menopausal Symptoms Worsening During Winters

One of the key changes during menopause is the steady decline in estrogen levels. Estrogen supports skin moisture, collagen formation, healthy hair growth cycles, and joint lubrication. As this hormone decreases, the body becomes more reactive to environmental factors, with winter dryness having a stronger impact.

Menopause In Winters: Why Skin Feels Drier in January

Tamanna Singh explains, “Cold air contains less moisture, and indoor heating further removes the skin’s natural oils. Lower estrogen levels weaken the skin’s protective barrier, increasing water loss. This leads to dryness, flaking, itching, and in some cases, eczema-like conditions. The skin also takes longer to repair itself, which makes winter-related irritation more difficult to manage.”

The Hair Fall Connection

Hair follicles respond closely to hormonal changes. Tamanna notes, “During menopause, shifting estrogen levels and increased androgen activity shorten the hair’s growth phase, leading to more shedding. Winter adds further stress through reduced blood flow to the scalp, dietary imbalances after festive eating, and low Vitamin D levels due to limited sunlight. Combined, these factors make January a common time for noticeable hair thinning and hair fall.”

Why Joint Pain Worsens During Menopause?

Estrogen also plays a role in reducing inflammation and keeping joints well-lubricated. As estrogen levels fall, women may experience stiffness, swelling, and discomfort, which tend to worsen in cold weather. Lower temperatures cause muscles and connective tissues to tighten, reducing flexibility. Staying less active during winter months further adds to joint stiffness and pain.

What Can Help?

Managing these concerns calls for a well-rounded approach. Tamanna recommends:

• Skin: Use rich, oil-based moisturisers regularly and maintain good hydration.
• Hair: Ensure sufficient intake of protein, iron, and biotin, and practice gentle scalp massage to improve blood circulation.
• Joints: Engage in light strength training, yoga, and regular movement to support flexibility. Adequate Vitamin D and calcium intake is especially important during winter.

Winter does not create menopausal symptoms. It simply intensifies what the body is already dealing with. With the right awareness, consistent care, and small seasonal adjustments, women can navigate the colder months with more ease and confidence.

Delhi’s air quality remained in ‘very poor’ category and a thick layer of fog also took over the city. As of 6am, the Air Quality Index or AQI stood at 385. On Monday, the AQI of the city stayed under the ‘severe’ category, and the overall 24-hour average was at 401. The India Meteorological Department (IMD) recorded that the general visibility of Delhi at 6.30am was 350 meters. The IMD also issued a fog alert for December 29 and the morning of December 30. Warning is also extended for neighboring states, including Haryana, Uttar Pradesh, Chandigarh, Punjab, and parts of Northeast, East, and North India.

The IMD on X wrote: “Dense to very dense fog is expected tonight and into the morning of 30th December across several regions including Haryana, Chandigarh & Delhi, Punjab, Uttar Pradesh, and parts of the Northeast, East, and North India. Visibility may be severely reduced, making travel risky. Please drive slowly, use fog lights, and avoid unnecessary journeys.”

Also Read: Is Delhi's Toxic Air Making You Sad And Grumpy? Here's What The Study Says

Pollution Could Harm Your Brain

While we all know the harm pollution could do to your lungs, doctors have also highlighted that pollution could also lead to cognitive ailments. Mental health impacts such as risk of depression, anxiety, ADHD, and neurodevelopmental disorders in children could rise.

Dr Deepika Dahima, a psychologist at AIIMS Delhi said that pollution could put mental health at risk. Prolonged exposure to fine particulate matter like PM10 or PM2.5 could lead to a rise in anxiety, depression, cognitive impairment and chronic stress. Children also show disrupted neural development and learning difficulties, while adults experience irritability, emotional fatigue and impaired decision-making.

Another medical practitioner, Dr Jitender Nagpal, deputy medical superintendent and pediatrician at Sitaram Bhartia Institute of Science, speaking to the news agency PTI said, “Increasingly, a wide spectrum of behavioural and learning issues such as attention difficulties, irritability, and poor academic performance are being noticed in many children.”

Studies too have linked the exposure of particulate matter or PM2.5 with increased ADHD risk. There are research that show a 1.51 fold increase per 5 μg/m³ increase in PM2.5 and others indicating elevated risks when exposure exceeds 16 μg/m³.

Another study published in December 18, in the journal Environmental Research by Oregon Health & Science University, found that everyday exposure to urban air pollution gradually alters brain development in children and young adults. The researchers of the Oregon Health & Science University discovered that exposure to air pollutants at ages 9 to 10 was associated with changes in cortical thickness in the frontal and temporal brain regions that are responsible for executive function, language, mood regulation, and socioemotional processing.

Another study published in Nature Communication notes that after four hours of exposure to particulate matter, it was found that people's ability to perform routine tasks and interpret emotions were highly impacted.

Study's co-author, Dr Thomas Faherty said, "Study provides compelling evidence that even short-term exposure to particulate matter can have immediate negative effects on brain functions essential for daily activities.”

Can Alzheimer's be completely reversed? This is not just about preventing it or ensuring it that the disease slow down, but can it be reversed to achieve full neurological recovery? For the longest, we have known that Alzheimer's is a progressive, degenerative brain disease, which destroys memory, thinking, and eventually the ability to perform simple tasks, but now a team of researchers from Case Western Reserve University, University Hospitals (UH), and Louis Stokes Cleveland VA Medical Center has challenged this belief. They may have found out something that could reverse it, at least so says the animal model.

Instead of targeting plaques or tangles alone, the team looked at something more fundamental: the brain’s energy system.

Their findings, published in Cell Reports Medicine, suggest that restoring the brain’s energy balance may not just slow Alzheimer’s but potentially reverse key features of the disease, at least in animal models.

What Did The Study Find?

The study is led by Kalyani Chaubey from the Pieper Laboratory, and at the center of the study is NAD+, a molecule essential for cellular energy and repair.

NAD+ levels naturally decline with age across the body, including in the brain. When levels drop too low, cells struggle to perform basic functions and eventually fail.

The researchers found that this decline is far more severe in the brains of people with Alzheimer’s. The same sharp drop was also seen in mouse models of the disease, pointing to a shared biological problem.

How the study was conducted

While Alzheimer’s is uniquely human, scientists use specially engineered mice to study it. In this study, two types of mice were used. One model carried human mutations linked to amyloid buildup, while the other carried a mutation affecting the tau protein.

Both amyloid and tau are central to Alzheimer’s pathology. Over time, these mice developed symptoms similar to human Alzheimer’s, including brain inflammation, damage to nerve fibers, breakdown of the blood-brain barrier, reduced formation of new neurons, and severe memory and learning problems.

Restoring energy balance in diseased brains

After confirming that NAD+ levels were dramatically reduced, the researchers tested whether restoring this balance could help. They used a drug called P7C3-A20, developed in the Pieper Laboratory, which supports cells in maintaining healthy NAD+ levels under stress.

Remarkably, the results went beyond prevention. Even when treatment began after significant disease progression, the mice showed reversal of major brain damage. Cognitive function fully recovered in both mouse models, despite their different genetic causes.

Biomarkers and what they signal

The recovery was not just behavioral. Blood levels of phosphorylated tau 217, a biomarker now used clinically in humans to detect Alzheimer’s, returned to normal in treated mice. This provided objective evidence that disease processes had been reversed, not merely masked.

Why this matters for people

The findings suggest a possible paradigm shift. Alzheimer’s damage may not always be permanent. Under certain conditions, the brain appears capable of repairing itself and regaining function.

However, the researchers caution against self-medicating with over-the-counter NAD+ supplements. Some have been shown in animal studies to raise NAD+ to unsafe levels that may increase cancer risk. The drug used in this study works differently, supporting balance rather than excess.