Reaching the age of 100 was, until a few decades ago, considered an extraordinary event. However, the number of people who reach this age continues to grow in many countries, arousing the interest of scientists who seek to understand what factors favor such a long life.

While genetics, diet, physical activity and environment all play a role, researchers have also begun to look at whether certain indicators present in blood tests can offer clues about who is most likely to become centenarians.

An extensive study conducted in Sweden followed thousands of people for decades to identify biological patterns associated with exceptional longevity. The results provide valuable insights into metabolism, inflammation, organ health, and other factors related to healthy aging.

The Blood Type and Longevity Study

The researchers’ goal was to determine whether blood tests performed many years earlier could be linked to the possibility of reaching 100 years of age.

To do this, they compared people who became centenarians with others who did not reach that age. One of the most important strengths of the study was that all participants were similar ages when the initial analyses were conducted, avoiding distorted comparisons between groups of different generations.

The scientists evaluated various markers related to metabolism, liver and kidney function, nutritional status, iron metabolism and some indicators linked to inflammation.

Follow-up lasted up to 35 years thanks to Swedish national registries, which provided precise information on each participant’s medical history, residence, and date of death.

The researchers stress that the purpose of the work was not to predict exactly who would live to be 100 years old, but to identify general trends within a broad population. In other words, the results show probabilities and associations, not individual certainties.

Who participated in the research?

The study used data from the well-known AMORIS cohort, one of Sweden’s leading medical databases.

From the more than 800,000 records available, the researchers selected 44,636 people born between 1893 and 1920. All participants had had blood tests between 1985 and 1996.

Throughout the follow-up, 1,224 people managed to reach 100 years of age. Approximately 85% of centenarians were women, a figure that coincides with the highest female life expectancy observed in many countries.

The scientists used sophisticated statistical methods to compare results, estimate probabilities, and detect biological patterns common among those who reached exceptional ages.

What blood markers were tested?

The researchers studied twelve common parameters in clinical analyses:

• Glucose.
• Total cholesterol.
• Creatinine.
• Albumin.
• Iron.
• Total iron fixing capacity.
• Uric acid.
• Aspartate aminotransferase (AST).
• Gamma-glutamyl transferase (GGT).
• Alkaline phosphatase (ALP).
• Lactate dehydrogenase (LD).
• Other indicators related to liver and metabolic function.

These markers made it possible to assess different aspects of the participants’ overall health many years before they reached advanced age.

One of the most interesting findings was that extremely high or extremely low values tended to be associated with a lower likelihood of becoming centenarian.

This reinforces a widely accepted idea in medicine: balance is often more beneficial than extremes.

The importance of maintaining healthy glucose levels

Glucose was one of the most relevant markers of the study.

People with higher values were less likely to reach 100 years of age. This result coincides with decades of research linking high blood sugar levels to damage to blood vessels, nerves and vital organs.

Keeping your glucose in healthy ranges not only helps prevent diabetes, but it can also support healthier aging.

A balanced diet, regular physical activity, weight control, adequate rest and stress reduction are essential tools to achieve this.

What the kidneys and liver reveal

Creatinine, used to assess kidney function, also showed an important relationship with longevity.

People with higher levels were less likely to become centenarians, highlighting the importance of preserving kidney health throughout life.

Something similar happened with several liver enzymes. Participants with elevated levels of GGT, alkaline phosphatase, and lactate dehydrogenase tended to be less likely to reach exceptional ages.

These results suggest that maintaining good liver and kidney health could play a relevant role in longevity.

Uric acid and inflammation: a possible key

Uric acid was another marker that caught the researchers’ attention.

People with lower levels were more likely to reach age 100 compared to those with higher values.

Scientists believe that this finding could be related to inflammatory and metabolic processes. While this is not a definitive test, it coincides with numerous studies linking chronic inflammation to less healthy aging.

It was also observed that low levels of C-reactive protein, an inflammatory marker widely used in medicine, appeared to be associated with increased longevity.

The role of cholesterol and iron

Cholesterol usually generates many doubts when talking about health and aging.

In this research, very low levels of total cholesterol were associated with a lower chance of reaching age 100. However, the researchers clarified that high levels did not increase the odds of reaching that age either.

This does not mean that high cholesterol is beneficial. It simply indicates that the relationship between cholesterol and longevity is more complex than is usually believed.

Iron showed a similar behavior. Very low levels were linked to a lower likelihood of becoming centenarian, possibly due to problems such as anemia, malnutrition or chronic diseases.

Again, the results suggest that balanced values appear to be the most favorable.

Is there a relationship with blood type?

While some previous research has explored possible links between certain blood types and longevity, this study focused primarily on blood biomarkers and found no conclusive evidence that a specific blood group guarantees a longer life.

Experts note that blood type can influence certain health risks, but longevity depends on a much broader combination of genetic, environmental and lifestyle factors.

Therefore, it is more useful to pay attention to modifiable indicators such as glucose, blood pressure, cholesterol, kidney function and inflammation.

What can we learn from these findings?

The results of this extensive follow-up suggest that those who reach very advanced ages tend to have more balanced biological profiles for decades.

Research shows that extreme values, especially in glucose, kidney function, liver enzymes and inflammatory markers, are associated with lower odds of reaching 100 years of age.

Although no analysis can predict a person’s future, maintaining healthy habits, carrying out regular medical check-ups and acting in time in the event of any alteration is still one of the most effective strategies to promote a long and healthy life.

In short, longevity seems to be less related to a single factor and more to the constant maintenance of an overall balance in health over the years.