Living to 100 was once considered extraordinary. Today, it’s becoming increasingly common.
In fact, centenarians—people aged 100 and above—are now the fastest-growing age group worldwide. Their numbers have been steadily rising for decades, prompting scientists to ask an important question:
What makes some people live longer than others?
A major long-term study suggests that part of the answer may lie in something surprisingly simple—your blood.
A Study Decades in the Making
Researchers in Sweden analyzed data from more than 44,000 individuals in Stockholm County. These participants, born between 1893 and 1920, had routine blood tests taken between 1985 and 1996.
Then came the long follow-up.
Scientists tracked these individuals for up to 35 years, monitoring health outcomes, diseases, and lifespan using national records.
Out of the entire group, 1,224 people lived to 100 years or more—and interestingly, the majority (over 84%) were women.
But the real focus wasn’t just who lived longer.
It was whether blood markers measured decades earlier could predict longevity.
The Blood Markers That Matter
The researchers examined 12 common biomarkers linked to overall health, including:
- Blood sugar (glucose) and cholesterol
- Kidney function (creatinine)
- Liver enzymes (GGT, ALP, LD)
- Iron levels and uric acid
- Albumin (a marker of nutrition)
Their conclusion was striking:
People who lived to 100 tended to have more balanced blood values—neither too high nor too low.
Key Findings on Longevity
According to lead researcher Karin Modig, certain patterns stood out clearly.
People who reached 100 generally had:
- Lower levels of glucose (blood sugar)
- Lower creatinine (better kidney function)
- Lower uric acid (linked to inflammation)
At the same time, extremes—on either end—reduced the chances of longevity.
In simple terms:
Balance matters more than perfection.
The Surprising Role of Cholesterol and Iron
One of the most unexpected findings involved cholesterol.
While high cholesterol is often seen as harmful, the study found that slightly higher levels in older adults were linked to better survival rates.
Similarly, very low iron levels were associated with a lower chance of reaching 100.
These findings challenge the idea that “lower is always better” when it comes to health markers.
Instead, they point toward a more nuanced truth:
Your body thrives in balance—not extremes.
Genes, Lifestyle, and a Bit of Luck
The study doesn’t claim that blood markers alone determine lifespan.
According to Modig, these markers likely reflect a combination of:
- Genetics
- Diet and nutrition
- Alcohol consumption
- Overall lifestyle habits
And of course, there’s always an element of chance.
Still, the fact that these differences appear decades before death suggests that long-term habits—and possibly genetics—play a meaningful role.
What This Means for You
This research isn’t about chasing “perfect” lab results.
Instead, it highlights the importance of maintaining stable, healthy ranges over time.
Simple habits can make a difference:
- Keep blood sugar levels under control
- Support liver and kidney health
- Avoid both nutrient deficiencies and excess
- Focus on consistent, sustainable lifestyle choices
Regular check-ups and tracking your health markers over time can provide valuable insight into your long-term wellbeing.
The Bigger Picture
Living to 100 isn’t just about luck—or even one single factor.
It’s about a combination of biology, lifestyle, and balance.
And while there’s no guaranteed formula for longevity, this study offers a powerful takeaway:
Your health today may shape your lifespan decades from now.
