In a stunning breakthrough, researchers have identified 10 specific blood “markers” that distinguish centenarians from those who die earlier, allowing them to predict who is more likely to reach 100 years.
Once considered medical marvels, centenarians are no longer as rare as they once were. In fact, the 100‑plus population now represents the fastest‑growing age group worldwide, with their numbers roughly doubling every decade since the 1970s.
This remarkable trend not only reflects improvements in healthcare and quality of life — it is also pushing scientists to investigate what’s happening inside the bodies of those who live the longest, especially at the microscopic level of blood and biology.
And a groundbreaking long‑term study from Sweden may hold the answers.
Tracked longevity for decades
Researchers analyzed 44,637 people from Stockholm County using data from a large population‑based resource of clinical lab results. All participants, born between 1893 and 1920 (ages 64 to 99), had routine blood tests taken between 1985 and 1996. Then came the long wait: they were tracked for up to 35 years through national registers documenting disease, death, and residency.
Of these individuals, 1,224 reached age 100, with 84.6% being women — consistent with known gender differences in longevity.
But the researchers weren’t just interested in who lived the longest. They wanted to know whether blood markers taken decades earlier could reveal who would eventually reach 100.
It turns out they could — at least to some extent.
Extreme values
The scientists examined 12 routine blood markers, including:
- Glucose and total cholesterol for metabolic health
- Creatinine for kidney function
- Liver enzymes such as gamma‑glutamyl transferase (GGT), alkaline phosphatase (ALP), and lactate dehydrogenase (LD)
- Iron markers and uric acid, often linked to inflammation
- Albumin, which reflects nutritional status
Their conclusion was clear: extreme values — either too high or too low — reduced the likelihood of reaching 100.
Key findings
“We found that, on the whole, those who made it to their hundredth birthday tended to have lower levels of glucose, creatinine and uric acid from their 60s onwards,” researcher Karin Modig writes in a Live Science article. “For example, very few of the centenarians had a glucose level above 6.5 earlier in life, or a creatinine level above 125.”
The findings showed that lower levels of glucose, creatinine, uric acid, ASAT, GGT, ALP, TIBC (total iron‑binding capacity), and LD were associated with a greater chance of becoming a centenarian.
Meanwhile, those with very low total cholesterol or iron “had a lower chance of reaching 100 years as compared to those with higher levels.”
Balanced take on cholesterol and iron
One of the most striking insights involved cholesterol.
“We found that a higher total cholesterol level was associated with a higher chance of becoming centenarian, which stands in contrast to clinical guidelines regarding cholesterol levels but is in line with previous studies showing that high cholesterol is generally favorable for mortality in very old age,” the study reports.
Similarly, extremely low iron levels were linked to lower odds of reaching 100 — highlighting the importance of maintaining balanced, rather than extreme, lab values.
Genes and lifestyle
According to Modig, the results “suggest a potential link between metabolic health, nutrition and exceptional longevity.”
“The study, however, does not allow any conclusions about which lifestyle factors or genes are responsible for the biomarker values. However, it is reasonable to think that factors such as nutrition and alcohol intake play a role. Keeping track of your kidney and liver values, as well as glucose and uric acid as you get older, is probably not a bad idea,” she explained.
“That said, chance probably plays a role at some point in reaching an exceptional age. But the fact that differences in biomarkers could be observed a long time before death suggests that genes and lifestyle may also play a role,” Modig added.
What this means for you
This isn’t a call to chase perfection in your lab results. It’s a reminder that staying within healthy mid‑range values may be more beneficial for long‑term health than trying to push certain numbers as low as possible.
Maintaining normal blood sugar, supporting kidney and liver function, and avoiding both nutrient deficiency and overload may help improve your odds. Speak with your doctor, monitor your trends, and focus on sustainable lifestyle habits such as better nutrition, physical activity, and sleep.
