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.

India accounts for one-fifth of global deaths due to cardiovascular diseases (CVDs) or complications related to the heart and blood vessels. Moreover, women are more vulnerable to these complications. Recent data show that women (14%) have a higher prevalence of CVD than men (12%), making preventive care very important for all.

When Should A Heart Check-up Be Done?

The human heart works constantly and efficiently and can compensate for metabolic stress and narrowing of blood vessels without showing any obvious symptoms. Hence, a heart health evaluation should ideally take place when the person is feeling completely well, long before any warning signs appear.

While acute symptoms, such as chest pressure or tightness, unexplained breathlessness, fainting, or unusual fatigue on effort, demand immediate attention, true heart protection occurs through early and planned tests. While heart check-ups are routinely recommended starting at age 40, screening should ideally begin earlier, around ages 30 to 35, especially if risk factors are present.

Starting check-ups at age 30 is important because certain congenital and structural heart conditions remain completely silent for years, and early screening ensures timely, targeted treatment when it is most effective.

Regular screening helps detect and rule out underlying issues early, including congenital heart defects (commonly known as holes in the heart) and conditions such as Atrial Septal Defect (ASD), Ventricular Septal Defect (VSD), or Patent Ductus Arteriosus (PDA). Structural and muscle diseases, on the other hand, include valve disorders, heart muscle weakness, or abnormal thickening of the heart walls (e.g., Hypertrophic Obstructive Cardiomyopathy (HOCM)).

Key Risk Factors

In addition to age, patients should seek a heart check-up sooner if they have any of the following risk factors:

• Strong family history of premature heart disease in immediate relatives.
• History of active or past smoking and tobacco use.
• Metabolic conditions such as diabetes, hypertension, or elevated blood cholesterol.

Excess body weight, especially central or abdominal obesity. Excess body weight damages the kidneys, leads to fat deposits in the liver and increases the risk of developing diabetes, and ultimately increases the strain on the heart and blood vessels (cardiovascular system). These interconnected conditions are known as Cardiovascular-Kidney-Metabolic (CKM) syndrome and include heart disease, kidney disease, diabetes, stetotic (fatty) liver disease, and obesity.

Effective weight and metabolic management, through modern options such as oral or injectable GLP1 therapies, can improve long-term heart health.

Tailoring care

A heart check-up can involve several tests, from blood tests to invasive or non-invasive ones (with/without needles, catheters, or probes entering the body). The most common blood tests include fasting and post-prandial or after-meal blood sugar (FBG/PPBG), HbA1c (glycated haemoglobin), lipid and thyroid profile, and kidney function tests. Non-invasive cardiac tests include electrocardiogram (ECG), 2D echocardiogram, and ultrasound. However, not everyone needs all of them.

Diagnostic tests should be customized based on the person’s age, symptoms, and individual risk score. Hence, skip the urge to self-order commercial diagnostic packages online. Instead, take the most important step towards protecting your heart by talking to your doctor. A personalized assessment can help determine which tests, if any, are appropriate for you, so that you can focus on the right steps to keep your heart healthy.

Gut chemicals may play a role in influencing the likelihood of someone developing Alzheimer's disease. A new study has a chemical produced by certain gut bacteria in focus that may affect Alzheimer’s disease risk, cognitive decline, and other changes related to the disease.

Published in Nature Communications, the study focused on imidazole propionate (ImP), a metabolite produced by some gut bacteria when they break down the amino acid histidine.

Researchers found that people with higher levels of ImP in their blood had lower cognitive scores and higher levels of biomarkers that indicate the likelihood of Alzheimer’s disease and neurodegeneration.

How Was The Study Conducted?

Also read: Global Life Expectancy Returns To Pre-Pandemic Levels, But NCDs Resulted In 8 Out 10 Deaths: WHO

The researchers studied health data from 1,196 adults who were cognitively unimpaired, with an average age of about 61 years. Higher blood levels of ImP were associated with poorer cognitive performance and faster age-related decline.

Higher ImP was also linked to increased levels of p-tau217, a key biomarker in Alzheimer’s pathology, and neurofilament light chain, a marker of nerve-cell damage.

The finding builds on earlier work from the University of Wisconsin-Madison team showing differences in gut microbes between people with Alzheimer’s and those without the disease.

“Since then, we've been trying to figure out how this difference in the gut perhaps leads to changes in the brain,” said Barbara Bendlin, professor of medicine at the University of Wisconsin-Madison.

But ImP itself may be more relevant than simply having a particular type of gut bacteria.

“ImP-producing bacteria are present in a large fraction of people, but they're not very abundant in most people,” said Federico Rey, professor of bacteriology at the University of Wisconsin-Madison. “But something we have learned over the years is that a microbe doesn't have to be abundant to have an impact on the host.”

Also read: Could This Popular Joint Supplement Turn Mild Cognitive Impairment Into Dementia? New Study Finds Link

Could Changing Your Diet Prevent Dementia Risk?

The researchers also found genetic evidence that linked higher ImP levels with an increased risk of Alzheimer’s. In experiments on mice, long-term exposure to ImP increased amyloid-beta plaques and signs of brain inflammation.

Laboratory experiments further suggested that ImP could affect the blood-brain barrier and promote tau hyperphosphorylation, a process involved in nerve damage that occurs in Alzheimer’s.

Researchers also caution against making changes to diet to alter gut bacteria. They say ImP is produced when bacteria metabolise histidine, an amino acid that the body needs and that is found in many protein-rich foods.

“Generally improving your diet would probably help,” Bendlin said. “But it's not as easy as saying, 'Stop eating eggs' or 'Don't eat so much red meat.' Because you need histidine, and it's all over the place.”

Instead, the researchers are looking at whether ImP itself could eventually be targeted.

“It could be just like cholesterol, where people with elevated cholesterol take a drug, a statin, that reduces their risk for heart disease,” Bendlin said. “If we can find an inhibitor that can help decrease the levels of ImP in the blood, that could hopefully reduce the risk of Alzheimer's and the speed of cognitive decline for a significant number of people.”

Researchers also say that the findings do not show that ImP causes Alzheimer’s in humans, nor do they suggest that probiotics or dietary changes can prevent dementia.

But they strengthen growing evidence that suggest chemicals produced by gut microbes may affect brain health years before symptoms surface.

A sudden twitch in the eyelid can be surprisingly unsettling. For some people, it may happen occasionally and disappear on its own, while for others, repeated twitching can lead to concerns about whether something more serious is going on.

The good news is that an occasional eyelid twitch is usually harmless and self-limiting. Stress is one of the common factors associated with it, but it is not the only one.

What causes an eye to twitch?

Eyelid twitching can often be associated with everyday factors such as stress, lack of sleep, high caffeine intake, smoking and general exhaustion.

For someone going through a stressful period or not getting enough rest, the twitch may appear and become more noticeable. High coffee or caffeine consumption can also be a contributing factor.

In most cases, the twitch settles on its own once the underlying trigger is addressed. It commonly resolves within a few weeks.

This means that an isolated eyelid twitch does not necessarily indicate an underlying eye or neurological disease.

Also read: Andrew Huberman’s Sleep Trick: Can Eye Movements Help You Fall Back Asleep?

Can reducing stress help?

Since stress, tiredness and lifestyle factors can contribute to eyelid twitching, addressing these factors can often help.

Getting adequate sleep, reducing caffeine intake and making time for relaxation can be useful. Meditation and relaxation exercises may also help, particularly when stress appears to be a contributing factor.

The key is to look at the bigger picture rather than immediately assuming that the twitch itself indicates a serious problem.

When should you see an ophthalmologist?

While an occasional twitch is generally not a cause for concern, it is worth consulting an ophthalmologist if the problem continues for several weeks or is accompanied by other symptoms.

Particular attention should be paid if there are:

• Changes in vision
• Swelling of the eyelids
• Difficulty or inability to open the eyes
• Other unusual symptoms accompanying the twitch

Persistent or unusual eyelid movements can sometimes be associated with conditions such as blepharospasm or hemifacial spasm, while certain neurological conditions can also present with symptoms that may initially resemble an ordinary eye twitch.

An ophthalmologist can assess the symptoms and determine whether further evaluation is required.

Also read: The Hidden Health Cost Of Excessive Screen Time: Dry Eyes, Ringing Ears, Poor Sleep

Does an eye twitch mean you have a neurological problem?

This is one of the biggest concerns people have when their eyelid starts twitching.

An isolated eyelid twitch, by itself, is usually not a sign of a serious neurological disease. Instead of focusing only on the twitch, individuals should pay attention to whether there are other neurological symptoms occurring at the same time.

Symptoms such as facial weakness, numbness, difficulty speaking or difficulty walking warrant medical attention and should not be ignored.

The presence of these accompanying symptoms is more significant than an occasional eyelid twitch on its own.

Don't let an occasional twitch cause unnecessary worry

Eyelid twitching can be irritating and, understandably, may cause anxiety. However, in most cases, it is temporary and can settle once contributing factors such as stress, fatigue or excessive caffeine consumption are addressed.

Getting adequate rest, reducing caffeine, managing stress and incorporating relaxation techniques can be simple first steps.

At the same time, persistent twitching or twitching accompanied by changes in vision, eyelid swelling, inability to open the eyes or other neurological symptoms should be evaluated by a medical professional.

The important distinction is between an occasional, isolated twitch and a persistent or unusual pattern accompanied by other symptoms. Knowing that difference can help people avoid unnecessary worry while also recognising when professional evaluation is appropriate.