Living past 100 isn’t just a milestone—it’s a biological mystery. For centuries, philosophers like Plato and Aristotle have speculated about aging, but only now, with modern science, are we beginning to decode the factors that separate the exceptionally long-lived from the rest of us.

And while lifestyle advice like “eat healthy” or “exercise regularly” still holds, new evidence suggests your blood might already be telling the story of how long you'll live decades before you reach old age.

A new study out of Sweden, published in GeroScience, has analyzed blood samples from over 44,000 people and tracked their health for more than three decades. The results? Those who lived past 100 shared subtle but consistent differences in certain biomarkers, particularly those tied to metabolism, inflammation, kidney and liver function, and nutrition

How Are Centenarians Biologically Distinct?

Centenarians (people who live to 100 or beyond) used to be statistical outliers. Today, they're one of the fastest-growing age groups in the world, doubling roughly every ten years since the 1970s. This demographic shift is forcing researchers to examine what exactly allows some people to not only live longer, but to live well into their 90s and beyond—often with fewer chronic conditions.

The Swedish study used data from the Amoris cohort, tracking people aged 64–99 for up to 35 years. Out of 44,000 participants, 1,224 (2.7%) lived to 100, and interestingly, 85% of them were women.

Rather than focus on anecdotal habits or isolated lifestyle factors, the researchers went straight to the bloodstream—measuring 12 key blood-based biomarkers that reflect various physiological processes including inflammation, metabolism, kidney and liver health, and nutritional status.

Subtle Signs That Set Centenarians Apart

When comparing those who lived to 100 with those who didn’t, the differences weren’t necessarily dramatic—but they were meaningful. One of the findings- centenarians tended to have lower levels of glucose, creatinine, and uric acid from their 60s onward.

While the median biomarker values weren’t always drastically different between groups, what stood out was that centenarians rarely had extremely high or low values. This biological "moderation" suggests that extreme metabolic fluctuations earlier in life may correlate with lower chances of exceptional longevity. For instance:

• Very few centenarians had glucose levels above 6.5 mmol/L.
• Likewise, only a small fraction had creatinine levels above 125 µmol/L.

Even uric acid often overlooked had a surprisingly predictive role. People with the lowest uric acid levels had a 4% chance of reaching 100, compared to just 1.5% among those with the highest levels.

What Exactly Biomarkers That Help You Live Longer?

The biomarkers measured in the study covered a wide range of physiological systems:

Inflammation: Uric acid

Metabolism: Total cholesterol, glucose

Liver function: Alanine aminotransferase (Alat), aspartate aminotransferase (Asat), albumin, gamma-glutamyl transferase (GGT), alkaline phosphatase (Alp), lactate dehydrogenase (LD)

Kidney function: Creatinine

Nutrition and anemia: Iron, total iron-binding capacity (TIBC), and albumin

What’s striking is that 10 out of the 12 markers were linked to the likelihood of becoming a centenarian, even after adjusting for age, sex, and disease burden.

Albumin and Alat were the only two that didn’t show a significant association—but the rest provided strong clues that biological aging begins much earlier than we think, and that it leaves a footprint in our blood.

Is There a Connection Between Nutrition, Metabolic Health and Longevity?

Although this study didn’t isolate specific lifestyle factors, the associations are suggestive. The fact that metabolic and nutritional biomarkers—like glucose, cholesterol, and iron, correlated with longer life spans aligns with broader research on the importance of diet, alcohol moderation, and weight stability in aging.

It's worth noting that both low and high levels of certain markers were associated with poorer outcomes, reinforcing the idea that optimal, balanced ranges not extremes may be most important when it comes to aging well.

This insight has practical implications: monitoring your metabolic and organ health in your 60s and beyond may provide an early-warning system for how your aging trajectory is shaping up.

Genes vs. Lifestyle: How Much Control Do We Really Have?

This study doesn't confirm whether genes or behavior drive the biomarker differences—it only shows that those who lived longest had more favorable profiles. According to Karin Modig, Associate Professor of Epidemiology at the Karolinska Institutet and lead author of the study, chance probably plays a role, but so do genes and lifestyle choices.

In other words, some people may be genetically predisposed to age more slowly, but even among those individuals, metabolic moderation and good organ function seem to be common themes.

You don't need to chase some mythical "perfect" blood profile but that small, cumulative differences in biological function across decades may matter more than we thought.

Paying attention to your glucose, creatinine, and uric acid levels as you age could help you catch red flags early. Liver and kidney markers, often underappreciated, may hold secrets to long-term health. Nutrition appears to play a much more central role in aging than many assume.

None of these factors guarantees you’ll live to 100—but they do suggest pathways worth preserving, monitoring, and optimizing.

This is the largest, longest-running study of its kind, and it delivers something few others have: longitudinal data on real people, across decades, tied to actual life outcomes.

Rather than rely on speculative theories or small anecdotal samples, the findings here provide a roadmap for future aging research, one that blends genetics, biology, lifestyle, and public health.

As the global population continues to gray, understanding how to extend not just lifespan but healthspan—the years of life spent in good health—will be critical. And studies like this bring us one step closer to unlocking the biology of exceptional aging.

World Breastfeeding Week: Breastfeeding is more than just feeding. It is a vital process of bonding, comfort, and trust between a mother and her newborn. It also plays a key role in the development of the infant and the wellbeing of the mother. While it is a natural process, understanding how lactation unfolds can make the journey smoother, especially for new mothers.

Breastfeeding is not meant for only feeding; it is also for bonding, giving comfort, and building a relation of trust from the very first time with the newborn. It is a natural process that supports both infant development and maternal health. Understanding the stages of lactation will help new mothers prepare for breastfeeding with knowledge and clarity.

Stage 1: Mammogenesis – Preparing the Body for Milk

Lactation begins even before the baby arrives. The first stage, known as Mammogenesis, starts during pregnancy. “The first one being, Mammogenesis, begins while the woman is pregnant, the hormones like oestrogen and progesterone stimulate the growth of breast tissues. This prepares the body to produce milk but holds on to actual secretion until after delivery,” explains Dr. S. Satyamanasa Gayatri Vinay, SRM Global Hospital, Chennai.

This stage is essentially about preparing the body to make milk, although milk itself is not produced yet. The hormonal activity ensures that the breast tissues are ready to take on the role once the baby is born.

Stage 2: Lactogenesis – From Colostrum to Milk

The second stage, Lactogenesis, occurs in two parts. “Lactogenesis I starts around the 16th week of pregnancy and continues until birth. During this stage, the breast produces colostrum, which is a thick, yellow, antibody-rich fluid that protects newborns from infections,” says Dr. Gayatri.

Colostrum is often referred to as the baby’s first vaccine. It is incredibly dense in nutrients and immune factors. After birth, the second part of this stage begins. “Lactogenesis II begins 2–3 days after delivery, with progesterone dropping and prolactin rising to the occasion; it signals the mother’s system to begin producing mature breast milk, perfect to nourish and comfort her newborn,” she adds.

During this time, many mothers may notice a fullness or warmth in their breasts, which is a sign that mature milk is being produced.

Stage 3: Galactopoiesis – The Supply-and-Demand Phase

Essentially, the more the baby nurses, the more milk the body will produce. It is a beautifully tuned supply-and-demand system.

The Role of Early Feeding and Skin-to-Skin Contact

Managing Challenges and Supporting the Mother

Like any new experience, breastfeeding may come with a few hiccups. "Issues such as delayed milk flow or sore nipples can be managed with proper latching of the baby, gentle massage, or lactation consultant support,” she advises. Seeking the right support early can make a world of difference for the mother.

Physical and emotional wellbeing are also key. “Keeping the mother’s body hydrated, a balanced diet with nutrients, a good amount of rest, and emotional support from close people – all of these contribute to improved breastfeeding. Stress can affect milk production, so a calm, supportive environment is important for the mother and the newborn,” Dr. Gayatri says.

Each phase of lactation serves a specific purpose, and understanding this journey empowers mothers to approach breastfeeding with confidence. From the early days of colostrum to the rhythm of regular feeds, it is a process that nurtures not just a baby’s body but the bond between mother and child.

Recent studies, including the one co-led by Ruben Juarez of the University of Hawaii has revealed the devastating and long-lasting health impacts of wildfires across the United States, far beyond what is reflected in official death tolls or injury reports. Studies focused on the aftermath of recent fires in Hawaii and California show that the true costs include a rise in mental health issues, respiratory damage, and deaths from disruptions in healthcare.

Beyond the Flames: Wildfires and Public Health

Three newly published studies have examined the lasting impact of the wildfires that devastated Maui in August 2023 and Los Angeles earlier this year. The Maui blazes, the deadliest in over a century in the US, killed more than 100 people and destroyed the historic town of Lahaina. In Los Angeles, fires that swept through areas like Altadena and the Pacific Palisades resulted in 31 confirmed deaths and the destruction of over 18,000 structures.

But new data suggests the indirect toll is even greater. Health outcomes linked to these events include a rise in suicides and overdose deaths, a significant decline in lung function, increased fatigue and weakness, and ongoing economic instability.

Maui’s Lingering Respiratory and Mental Health Crisis

One of the studies, by Juarez, focused on over 1,100 adults living in affected areas of Maui six to 14 months after the fires. The findings are concerning. People living close to the fire zone had notably lower lung function compared to those in areas with less smoke exposure. About 22% of participants experienced below-normal lung performance.

Nearly 40% of those surveyed said their overall health had worsened since the fires. Many reported symptoms such as fatigue, weakness, eye irritation, and respiratory problems. Additionally, almost half of the participants displayed signs of depression.

Juarez emphasized the importance of understanding that wildfires can leave "an invisible but lasting scar on respiratory health," long after the visible damage has been cleared.

Suicide and Overdose Deaths Surge in Maui

Another study highlighted the mental health toll of the Maui wildfires. In the month of the fires, suicide and overdose deaths in Maui nearly doubled. There were 13 such deaths during that time, with most being suicides. That marked a 97% increase on the island. A 46% spike was observed across Hawaii’s five counties, likely influenced by displaced residents relocating from Maui to other islands.

The rise in such deaths returned to normal in the following months, but the short-term spike has raised alarms about the psychological trauma triggered by these disasters.

Los Angeles Fires and the Hidden Death Count

A separate study led by Finnish researchers focused on the Los Angeles fires. While the direct death toll was 31, the researchers estimated that over 400 additional deaths occurred between January and February due to indirect consequences such as healthcare disruptions. These deaths would not typically be included in official wildfire statistics but are part of the broader public health burden caused by such disasters.

Dr. Jonathan Patz, an environmental public health expert from the University of Wisconsin, said the findings add critical knowledge to the true health risks of extreme climate events, reports the Guardian.

The Growing Concern Over Wildfire Smoke

As wildfires become more frequent and intense due to climate change, scientists are paying closer attention to the dangers of wildfire smoke. It is now believed that this smoke may be more toxic than regular air pollution. Kristie Ebi of the University of Washington explained that wildfire smoke is a mixture of many dangerous substances, reports the Guardian. It includes not only burning trees and vegetation, but also chemicals released from gasoline stations, old homes containing asbestos, and vehicles.

Ebi noted that the Maui study hints at the potential for long-term lung damage, though more research is needed to fully understand the long-term effects.

Economic Fallout: Housing and Income Loss

Beyond health, the economic impact of wildfires can be long-lasting. A new report by the University of Hawaiʻi Economic Research Organization (UHERO), based on nearly a year of data, showed that many families in Maui are still struggling. While some have managed to find permanent housing and regain financial stability, a significant number remain displaced, with high rent burdens and income loss.

Poverty in the region has almost doubled since the fire. Full-time employment has not yet returned to pre-fire levels, and 60% of households report lower income.

Daniela Bond-Smith, a UHERO research economist, as reported by the Guardianm described the community as facing "two realities." While some are rebuilding their lives, others—especially those who were already marginalized—are living in continued uncertainty and hardship.

In today’s fitness-obsessed world, being in good shape is often equated with being healthy. But that assumption is increasingly being challenged. You might clock your daily steps, hit the gym, and look lean in the mirror, yet your body may still be signalling distress from the inside. And the problem usually lies in the gut.

The growing evidence shows how a well-sculpted exterior does not always reflect internal well-being. Fitness is not enough to ensure health. The gut microbiome may be the silent disruptor behind many metabolic issues, even in those who appear outwardly fit.

In fact, a review by the Indian Council of Medical Research found that more than 71 per cent of Indian adults are metabolically unhealthy despite looking lean. This startling figure highlights a crucial gap in our understanding of what it really means to be healthy.

Also Read: As China Revives COVID-Era Measures To Beat Chikungunya Virus, Here's All You Should Know About This Mosquito-borne Disease

What Does “Fit but Not Healthy” Mean? Expert Explains

“Even top-level athletes can develop overtraining syndrome,” Dr. Dhar explains, describing this as a condition marked by systemic inflammation, hormonal imbalance, and metabolic dysfunction. And at the heart of it, he notes, is often a disrupted gut microbiome.

He warns that a dysfunctional gut flora does not just impact digestion; it can lead to inflammation, reduce insulin sensitivity, interfere with lipid metabolism, and elevate the risk of chronic conditions. “Even world-class athletes are not immune,” he adds.

The Gut-Fitness Connection

But, he cautions, “Overtraining or intense workout regimens can backfire.” When pushed too far, physical activity can damage the gut lining, increase inflammation, and throw off microbial balance, a state known as dysbiosis.

“So, while exercise is crucial, it has to be done in a way that complements gut health,” he advises.

Gut Microbiome Plays A Crucial Role

“When this balance is disturbed, we see the emergence of conditions like chronic inflammation, insulin resistance, inflammatory bowel disease (IBD), and even obesity,” he says. This microbial imbalance often remains hidden, as most people rely on weight or BMI as their main health markers.

He points out how even something seemingly harmless, like eating a few cookies a day, can slowly tip the scales of gut balance and trigger low-grade inflammation. “This kind of hidden obesity often flies under the radar,” says Dr. Dhar.

Moving Toward True Health

• Focus on dietary diversity: Eating a wide variety of plant-based foods supports microbial diversity and resilience.
• Include prebiotics and probiotics: He recommends incorporating fermented foods and fibre-rich legumes, noting their benefits for mood, weight, and metabolic health.
• Balance exercise intensity: Moderate exercise enhances gut health, but too much intensity can be harmful.
• Monitor metabolic health: He urges people not to rely solely on weigh-ins. Regular metabolic screenings and, where possible, microbiome testing can uncover hidden health risks early.

Being in shape is not a guarantee of being healthy. Without good gut health, even disciplined exercise and a lean appearance can mask deeper problems like inflammation or insulin resistance. Dr. Dhar calls the gut our “second brain” and insists it deserves more attention than it typically receives. It is time to stop obsessing over what we see in the mirror and start listening to the internal cues.

True health, he concludes, lies in nurturing the gut through balanced movement, diverse diets, quality sleep, and stress management.