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.

Participating in ultra-marathons can cause damage to your red blood cells' flexibility and hamper their oxygen-carrying capacity, a study suggests.

A study published in the American Society of Hematology’s journal Blood Red Cells & Iron notes that extreme forms of exercise may harm, rather than support, overall health.

In the case of ultra-marathons, runners experience breakdown of normal red blood cells during races. Over time, their red blood cells become less flexible and potentially reduce their ability to efficiently carry oxygen, nutrients and waste products throughout the body.

Travis Nemkov, associate professor in the department of biochemistry and molecular genetics at the University of Colorado Anschutz and the study’s lead author said of the results: “Participating in events like these can cause general inflammation in the body and damage red blood cells.

“Based on these data, we don’t have guidance as to whether people should or should not participate in these types of events; what we can say is, when they do, that persistent stress is damaging the most abundant cell in the body.”

Red blood cells transport oxygen and waste throughout the body and must be flexible enough to squeeze through small blood vessels. When red blood cells become inflexible or rigid, they lose their ability to deform and navigate through the body's smallest vessels, leading to impaired oxygen delivery, blockage of blood flow, and rapid destruction by the body's filtration system.

This can lead to low hemoglobin and anemia which can pave the way for diseases like Sickle Cell Disease (SCD), thalassemia, hereditary spherocytosis, and, in some cases, the "storage lesion" of blood in transfusion banks.

READ MORE: Ultra Marathoner Sufiya Sufi Runner: The Woman Who Set 5 Guinness World Records

What Is Low Hemoglobin?

Hemoglobin is the oxygen-carrying protein in red blood cells. Adequate hemoglobin levels are essential for keeping organs and tissues properly supplied with oxygen. Without enough of it, the body begins to struggle to meet its basic energy needs.

Low hemoglobin is usually identified through a blood test. It is most often measured as part of a complete blood count (CBC), which checks different components of the blood, including red and white blood cells and platelets, as per Healthline.

While exact reference ranges can vary slightly between laboratories, healthy adult hemoglobin levels usually fall within the ranges listed below. These values are different for babies, children, and teenagers:

• Normal Hemoglobin Count in Grams per Deciliter (g/dL) | Normal Hemoglobin Count in Grams per Liter (g/L)
• Adult Males: 13.8–17.2 | 138–172
• Adult Females: 12.1–15.1 | 121–151

Any reading below these ranges in adults is considered low hemoglobin and suggests that oxygen delivery in the body may be reduced, as per Mayo Clinic.

Is Low Hemoglobin Ever Dangerous?

Low hemoglobin is not always an emergency. In many cases, it develops gradually and can be managed with treatment. That said, very low levels can be dangerous. A hemoglobin level below 5.0 g/dL has been linked to serious complications, including heart failure and even death. Levels under 6.5 g/dL may be considered life-threatening and require urgent medical care.

What Causes Low Hemoglobin?

One of the most common reasons for low hemoglobin is anemia. Anemia occurs when the body does not have enough healthy red blood cells. The most frequent type is iron-deficiency anemia, which develops when the body lacks enough iron to produce hemoglobin.

Other forms of anemia include pernicious anemia, which occurs when the body cannot properly absorb vitamin B12, and hemolytic anemia, where red blood cells are destroyed faster than they are produced.

Low hemoglobin can also be caused by:

• Blood loss or internal bleeding
• Certain cancers, including leukemia, lymphoma, multiple myeloma, and cancers that spread to the bone marrow
• Chronic kidney disease
• Deficiencies of folate or vitamin B12
• Hypothyroidism
• Liver disease
• Poor nutrition or malnutrition
• Myelodysplastic syndrome (MDS)
• Sarcoidosis
• Sickle cell disease and other inherited blood disorders
• Systemic lupus erythematosus
• Thalassemia, a genetic condition that reduces hemoglobin production
• Excess fluid in the body
• Cancer treatments such as chemotherapy and radiation can also lower hemoglobin levels, particularly in adults over the age of 65.

What Does Having Low Hemoglobin Feel Like?

• Feeling dizzy or lightheaded, sometimes fainting
• Muscle weakness
• Ongoing fatigue or low energy
• Pale or washed-out skin
• Frequent headaches

How Is Low Hemoglobin Treated?

Treatment depends entirely on what is causing the low hemoglobin. A healthcare provider will first identify the underlying reason before recommending treatment. Possible treatment options include:

• Blood transfusion: If hemoglobin is low due to heavy blood loss, a transfusion may be needed to restore levels quickly.
• Vitamin supplements: When nutritional deficiencies are the cause, iron, folate, or vitamin B12 supplements are often prescribed. Hemoglobin levels usually begin to improve within six to eight weeks.
• Intravenous (IV) therapy: In cases where iron or B12 levels need to be raised rapidly, IV infusions may be recommended.
• Bone marrow transplant: This may be required when low hemoglobin is linked to certain cancers or bone marrow disorders.

If a long-term illness is responsible, managing that condition becomes the key part of treatment, alongside monitoring hemoglobin levels regularly.

Researchers from Denmark and Australia have discovered a new virus in the gut that can contribute to the development of colorectal cancer in the body, one of the leading causes of death in the world.

Using genetic sequencing, researchers studied the gut bacteria of cancer patients in a large Danish study and found that Bacteroides fragilis, an anaerobic, gram-negative, pleomorphic to rod-shaped bacterium, often carried a bacteriophage — a virus that infects and reproduces inside bacteria.

This allows it to produce a toxin (BFT) in the colon, promoting chronic inflammation, cell proliferation and tumor growth in the region.

People with colorectal cancer were twice as likely to have this bacteriophage in their gut bacteria. The virus also appears to be previously unknown and does not match any recorded type so far.

Although the first finding came from a small group, it was later confirmed in a larger study of 877 people with and without colorectal cancer. The results suggest that viruses hiding inside B. fragilis may play a role in cancer development.

Microbiologist Flemming Damgaard, from Odense University Hospital in Denmark: "It has been a paradox that we repeatedly find the same bacterium in connection with colorectal cancer, while at the same time it is a completely normal part of the gut in healthy people.

"We have discovered a virus that has not previously been described and which appears to be closely linked to the bacteria we find in patients with colorectal cancer."

What Is Colon Cancer?

Colon cancer develops from polyps in the colon or rectum, often taking years to show symptoms. The cancer begins when small growths called polyps form on the inner lining of the colon or rectum. Over time, changes in the DNA of these cells can cause the polyps to become cancerous.

As abnormal cells multiply, they replace healthy cells and eventually form a mass known as a tumor. This process develops slowly, often taking up to ten years for a precancerous polyp to turn into cancer and begin showing symptoms.

The American Cancer Society notes that colorectal cancer impacts around 1.9 million people every year.. In India, it is the fourth most common cancer among both men and women. In 2022, there were 64,863 new cases and 38,367 deaths.

Projections suggest that incidence will continue to rise by 2026, reflecting both lifestyle changes and improved detection.

Colon cancer can be difficult to detect because it often develops without obvious symptoms. According to experts , these are the three things you should do to protect yourself:

1. Timely risk screening

2. Knowing your cancer family history

3. Acting on early symptoms

What Early Symptoms Should You Look Out For?

Colon cancer rarely announces its presence with dramatic symptoms. More often, it whispers — through changes in bowel habits, subtle abdominal discomfort, or unexplained weight loss.

Some of the most commonly missed early signs include:

• Persistent changes in bowel movements: Chronic constipation or diarrhea often dismissed as dietary effects.
• Blood in stool: Bright red or dark blood should not be ignored.
• Unexplained weight loss: Especially when unintentional.
• Abdominal cramps or bloating: Misinterpreted as common digestive issues.

Persistent changes in bowel habits, especially if they last more than a few days, must be taken seriously. Narrow or ribbon-shaped stools may indicate a tumor partially blocking the colon.

Schizophrenia is a severe, chronic brain disorder that can lead psychosis, hallucinations, delusions, disorganized thinking and reduced emotional expression. It can affect how a person thinks, feels and behaves, making it hard to distinguish reality.

The chronic neurological condition affects less than one percent of the global population and typically emerges in late teens to early thirties, requiring lifelong treatment.

However, Canadian researchers have now pointed towards the placenta as a possible source of early indicators of schizophrenia risk.

According to the scientists, the placenta can "record" what happens during pregnancy and can reflect both healthy and unhealthy conditions for the baby, a phenomenon known as the placenta-brain axis.

The theory suggests that when the placenta is negatively affected, brain development may also be harmed in both the short and long term and increase the baby's risk of developing the lifelong condition.

Multiple large-scale studies have found that in pregnancies where babies are born with low birth weight, certain genetic markers in the placenta are altered. These changes are strongly linked to a higher risk of schizophrenia and other developmental problems, such as autism and learning difficulties.

There is also strong evidence that using cannabis during pregnancy can harm a baby’s brain development and increase the risk of schizophrenia.

However, while cannabis use during pregnancy is known to be linked to low birth weight, it is still unclear whether cannabis exposure affects the same placental genetic markers associated with schizophrenia.

How Is Brain Impacted During Schizophrenia?

In schizophrenia, the brain experiences structural and chemical changes that disrupt normal thinking, emotions, and behaviour. Research shows that people with schizophrenia often have reduced grey matter volume, particularly in areas involved in memory, emotion, and decision-making, like the hippocampus and prefrontal cortex.

Abnormalities in neurotransmitters, especially dopamine and glutamate, also play a key role, leading to symptoms such as hallucinations, delusions, and cognitive difficulties. Connectivity between different brain regions may become impaired, affecting the brain's ability to process information smoothly.

These changes typically emerge gradually, often beginning in late adolescence or early adulthood, and vary significantly from person to person.

How To Identify Schizophrenia?

According to the DSM-5 (Diagnostic and Statistical Manual of Mental Disorders, 5th Edition), schizophrenia is diagnosed based on a set of specific symptoms. Here's the list of core symptoms:

• Delusions – strong false beliefs not based in reality (e.g., believing you are being persecuted or have special powers).
• Hallucinations – hearing, seeing, or sensing things that aren't actually there (most commonly auditory hallucinations).
• Disorganised speech – frequent derailment, incoherence, or illogical conversation.
• Grossly disorganised or catatonic behavior – unpredictable agitation, inappropriate behaviour, or lack of movement/responsiveness.
• Negative symptoms – diminished emotional expression, reduced motivation (avolition), reduced speech (alogia), social withdrawal, or inability to experience pleasure (anhedonia).