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.

Bryan Johnson, the billionaire biohacker and longevity enthusiast, has been diagnosed with an incurable autoimmune disease called Autoimmune Gastritis (AIG).

Johnson is known for his radical longevity experiments, including measuring the biological age of his organs in an effort to reverse aging, injecting himself with ketamine, taking over 50 pills a day, undergoing fat transfers, and receiving blood transfusions from his teenage son.

In a recent post on X, he made the shocking announcement of his autoimmune conditions, which went undetected for years: Autoimmune Gastritis.

Calling it "bad news," Johnson wrote: "I have an autoimmune disease. My stomach is eating itself."

"2-5 per cent of people have this, too. Likely more, because it hides," he added.

According to Johnson, his stomach had been attacking itself without causing noticeable symptoms. The condition was only discovered in May.

Also read: Bryan Johnson Blames Sugary Cereals, Soda and Stress for His Autoimmune Disease; Shares Treatment Plan

The Early Warning Sign: Low Ferritin

Autoimmune Gastritis, a condition in which the immune system attacks the stomach's acid-producing cells, also impairs the absorption of iron and vitamin B12.

Johnson said one of the earliest signs of the condition was persistently low ferritin levels over the past 11 years despite not having anemia.

"We continually tried to raise my iron levels with food and supplementation, but nothing would work."

He said he followed a plant-based diet, trained intensely, used a sauna and hyperbaric oxygen therapy, and took iron supplements, yet his iron levels remained low.

Ferritin stores the body's iron. Iron is essential for transporting oxygen and producing energy, and low iron levels can lead to fatigue, weakness, and dizziness.

Johnson said autoimmune gastritis is difficult to diagnose because its earliest clue is often overlooked.

"The earliest clue, low ferritin, is the one standard medicine waves through. Low iron stores get normalized and rarely investigated at all when anemia hasn't shown up yet. That blind spot is what hid mine for a decade."

While initially it wasn't clear why his iron levels were continuously dipping, after further testing, Johnson's team identified three interconnected issues.

Read More: Bryan Johnson Battles Autoimmune Gastritis: Which Parts Of His Longevity Guide Are Actually Worth Copying?

Autoimmune Gastritis was preventing normal iron absorption by damaging the stomach cells that produce acid. He also discovered autoimmune thyroid disease.

"The iron deficiency, the autoimmune gastritis driving it, and the autoimmune thyroid disease alongside it. Iron and thyroid feed each other both ways; low iron impairs the conversion of thyroid hormone into its active form, and an underactive thyroid impairs how the body uses iron," Johnson explained.

Iron Deficiency May Be More Common Than Many Realize

According to research published in JAMA Network Open, about one in four Americans may have inadequate iron intake or absorption.

As per the study of more than 8,000 Americans, 14 per cent of adults had absolute iron deficiency, reflecting depleted iron stores.

Even after excluding common causes such as anemia, pregnancy, heart failure, and chronic kidney disease, 11 per cent remained iron deficient. Another 15 per cent had functional iron deficiency, where iron levels appear normal but the body cannot use the mineral effectively.

How Bryan Johnson Is Managing The Condition

Since receiving the diagnosis, Johnson has begun iron infusions, which deliver a full dose of iron in a single treatment.

He said his team will continue routine monitoring of his ferritin and iron levels.

Johnson ended his post with a warning that hidden health conditions can go unnoticed for years.

"You too may have a lurking health issue that is undiagnosed and could increase in severity from unhealthy life choices, without your knowing… A gentle nudge that minding your health, no matter your situation in life, is a good decision-making."

A recent study has indicated that following a healthy diet consistently may help reduce the risk of dementia, even in those who already show early signs of Alzheimer's disease. The study could help in early management of neurodegenerative diseases like dementia.

Anti-Inflammatory Diet May Help Lower Dementia Risk

According to a new study published in the JAMA Network Open, scientists found that participants who maintained better-quality diets over a period of 15 years were less likely to develop dementia, regardless of whether their blood tests indicated the presence of Alzheimer ’s related biomarkers.

The findings also suggest that healthy eating habits may benefit even after the individual shows signs of the disease processes have begun.

About The Study And Its Results

The researchers followed middle-aged and older adults one and a half decades, examining their dietary habits alongside blood biomarkers associated with Alzheimer's disease, including phosphorylated tau217 (p-tau217), glial fibrillary acidic protein (GFAP), and neurofilament light (NfL).

These biomarkers are commonly used to detect early Alzheimer's-related changes and neurodegeneration before symptoms of the disease become visible.

The participants followed a healthy diet, particularly a Mediterranean-style as well as an anti-inflammatory diet. The findings showed that individuals with healthier diets had a lower risk of developing dementia over the follow-up period.

Remarkably, this association was observed even among participants who presented Alzheimer's biomarkers, indicating that diet may offer protective benefits despite early signs.

Alzheimer's disease begins years, and sometimes decades, before memory problems emerge. During this preclinical stage, abnormal proteins accumulate in the brain while individuals remain symptom-free.

Read more: New Blood Test May Predict Alzheimer's Symptoms At Least 4 Years In Advance: Study

The new findings indicate that lifestyle factors such as diet could still influence dementia risk even after these biological changes have started. This reinforces growing evidence that preventive measures need not be limited to people without detectable Alzheimer's pathology.

Not A Preventative Measure

While the study shows promising results of the effect of a healthy diet on the neurodegenerative disease, it does not prove that diets can directly prevent dementia.

The researchers emphasized that the study was merely an observation, meaning it highlighted an association rather than a direct cause-and-effect relationship. It just supports the idea that long-term healthy eating could have a significant impact on one’s brain health throughout adulthood.

Benefits Of Anti-Inflammatory & Mediterranean Diets

The anti-inflammatory diet, as recommended by Harvard Nutrition Source, helps calm the immune system by choosing foods that reduce inflammation.

This dietary approach encourages a balance of fruits, vegetables, healthy fats, whole grains, and other nutrient-dense foods while avoiding those that trigger inflammation.

On the other hand, Mediterranean diet, long celebrated for its heart-and longevity-promoting benefits, is now gaining attention for its beneficial effects on the brain.

This diet emphasizes plant-based foods, healthy fats such as extra virgin olive oil, nuts, fruits, vegetables, and whole grains, with moderate fish intake.

In another study published in Nature Medicine, researchers observed that individuals at the highest genetic risk for Alzheimer’s disease, particularly carriers of the APOE4 gene variant, showed the most significant reduction in dementia risk when adhering closely to this dietary pattern.

Parkinson’s disease is the second most common neurodegenerative disorder in the world and is the fastest-growing neurological condition worldwide. Its classic hallmarks - resting tremor, bradykinesia, and rigidity usually lead to diagnosis only after extensive dopaminergic neuronal loss has already happened. Newer research, however, highlights a prodromal window that might open decades earlier. There’s an increasing theory that pathological changes of the nervous system could start in a person’s 20s. This means that early detection is not just desirable but could be transformative for clinical outcomes.

Individuals with PD at prodromal and early motor stages alike report symptoms in multiple domains, including behavioral, cognitive, autonomic, sensory, sleep-related, and activities of daily living. Most of these symptoms are subtle and overlap with common conditions, so they aren’t often recognized or are mistaken for ageing, stress or other lifestyle factors. So, identifying consistent patterns amid daily behavioral variations is crucial for improving early PD detection.

Sleep Disturbances: An Early Warning Sign

One of the most robust prodromal markers is REM sleep behavior disorder (RBD). People who are affected have sleep disruption, physically act out their dreams during REM phase (acting out dreams), and vivid dream life and some through sleepwalking — all of them worthy substrates for signals of early brainstem pathology.

Loss of Smell May Appear Years Before Diagnosis

Anosmia, a partial or complete loss of the sense of smell, could be PD’s earliest recognizable sign, occurring as much as 10 years before motor signs become apparent. In practice, this means being unable to easily perceive familiar smells like food or coffee. Because this symptom manifests so early and appears so unrelated to the health of the brain, it is rarely taken seriously in clinical practice.

Gut Changes and the Brain Connection

Chronic constipation is a common prodromal symptom indicating reduced gut motility that can predate motor symptoms by years. This observation is consistent with the gut–brain axis hypothesis: gut microbiota dysbiosis disrupts gastrointestinal motility, permeability and inflammation, which may facilitate a prion-like transmission of misformed alpha-synuclein (α-syn) from gut to brain through the enteric nervous system.1 further underscoring the biomarker potential of gastrointestinal symptoms with clinical relevance.

Subtle Changes in Movement and Mood

Before tremors are apparent, there can be subtle changes in fine motor control. Trouble with tasks such as handwriting, using electronic devices or manipulating small objects, along with uncharacteristic anxiety or a low mood, can serve as signals of the preclinical stage. Micrographia (progressively smaller and cramped handwriting) is a particularly telling sign from daily life that deserves a neurological workup when it appears without an obvious cause.

Fatigue and Autonomic Symptoms Can Precede Motor Signs

Fatigue that never seems to get better with rest affects work performance, social engagement and daily motivation, and can occur long before an official diagnosis. More than half of all PD patients develop at least one form of autonomic dysfunction, which can precede motor symptoms by four years or more, and is now being recognized as a key prognostic biomarker for prodromal PD. Cardiovascular instability, orthostatic hypotension, and urinary irregularities further influence how individuals navigate everyday environments long before a definitive diagnosis is made.

Recognizing Early Signals Can Transform Care

The evidence reviewed here collectively supports a paradigm shift: Parkinson's disease is best defined as systemic, progressive, and with recognizable signals in daily life long before motor signs of decline. Disrupted sleep, anosmia, gastrointestinal changes, fine motor difficulties and chronic fatigue are not complaints in a vacuum; they are potential early signs of a neurological process left unsupervised and now in motion. Incorporating routine clinical assessment of these behavioural precursors and pre-motor signs would allow us to meaningfully extend the opportunity for therapeutic intervention, which could in turn improve patient outcomes across a broad range of CNS disorders.