Does Human Longevity Have An Upper Limit?
Do people live longer today than before?
Yes, people live significantly longer today than they did in the past, thanks to a variety of improvements in medicine, public health, nutrition, and overall living conditions.
In historical times, life expectancy was much lower due to high infant mortality rates, lack of modern healthcare, and widespread infectious diseases. For example, in the early 1800s, global average life expectancy was around 30-40 years. This was due largely to poor sanitation, limited medical knowledge, and frequent outbreaks of deadly diseases such as smallpox, tuberculosis, and cholera.
Over the 20th and 21st centuries, major advancements in healthcare, including the discovery of vaccines, antibiotics, and the development of modern medical practices, have drastically improved human longevity. Public health initiatives such as improved sanitation, cleaner drinking water, and better nutrition have also played a crucial role in reducing early mortality rates.
By 2020, global average life expectancy had risen to around 72 years. In high-income countries like Japan and Switzerland, the average longevity exceeds 80 years. Even in lower-income countries, life expectancy has increased substantially due to international efforts to reduce diseases such as malaria, improve access to vaccines, and address malnutrition.
While these improvements are notable, it’s important to note that differences in life expectancy persist between regions due to factors like healthcare access, economic inequality, and lifestyle factors. The rising prevalence of chronic diseases such as heart disease and diabetes in some countries has also created new challenges for increasing life expectancy further.
Elderly woman – illustrative photo. Image credit: Piqsels, CC0 Public Domain
What aspects of modern life contribute to longer life expectancy?
Key factors contributing to longer life expectancy today include these important aspects:
- Vaccination and antibiotics: These have dramatically reduced deaths from infectious diseases that were once widespread.
- Better nutrition: Increased access to a balanced diet has contributed to healthier populations.
- Medical advancements: Surgical techniques, medical technologies, and cancer treatments have improved survival rates for previously fatal conditions.
- Public health initiatives: Sanitation improvements, clean water access, and health education have reduced death rates.
- Chronic disease management: Advances in the treatment of diseases like diabetes, hypertension, and cardiovascular issues have extended the lives of many.
Looking to the future, innovations like personalized medicine, gene therapy, and advancements in artificial intelligence could further increase life expectancy. However, managing the socioeconomic and healthcare disparities that still exist will be crucial in ensuring that these gains are widespread.
Has global longevity growth decelerated recently?
In the 20th century, the average human lifespan increased by about three years per decade in most developed countries. However, recently, there has been a decrease in the rate of improvement in average life expectancy.
A recent paper has examined changes in death rates and life expectancies from 1990 to 2019 in the world’s eight longest-lived countries. In most of them, the improvement in life expectancy decelerated. If humanity had kept pace with the previous rate, about one in five Japanese women would live past 120. However, the reality is far from that.
Many biological processes, some of which aren’t fully understood, happen as humans age. These can lead to such conditions as frailty, dementia, heart disease, and sensory impairments. These conditions hinder the growth of life expectancy.
Medical lab – illustrative photo. Image credit: NCI
Is there a ceiling to the human lifespan?
Novel advances in medical research, such as those concentrating on the world’s longest-lived populations, may give rise to new interventions and therapies targeting the aging process. However, it’s unlikely that human longevity will increase dramatically in already long-lived countries. The current limit to the average lifespan seems to be around 85 years. The complexity of aging processes makes it unlikely that we will see a breakthrough in the near future.
A recent study brings forth the possibility that human life expectancy might have a natural cap, suggesting an upper limit between 120 and 150 years. According to findings published in Nature Communications, the human body would, by this age, lose its capacity to recover from everyday stresses like illness, making survival beyond that point unlikely.
This longevity-related research was based on data gathered from over 500,000 individuals, analyzed through a novel metric called the “dynamic organism state indicator” (DOSI). This metric differentiates between:
- biological age—how worn down cells and organs are—and
- chronological age, as determined by the objective flow of time.
Peter Fedichev, a senior researcher on the study, explained that while reducing frailty and combating disease might extend life somewhat, it won’t significantly stretch the human lifespan. To break the 150-year barrier, new therapies would need to enhance the body’s ability to regenerate and remain resilient as it ages.
The research team arrived at these findings by analyzing two key biomarkers: the ratio of white blood cells (a critical part of the immune response) and the variability in the size of red blood cells. These biomarkers were fed into a computer model to estimate the biological limits of human life.
The model suggests that even in ideal circumstances, the body’s regenerative abilities would be so depleted by age 150 that sustaining life becomes impossible, which in turn puts the ‘ceiling’ on the theoretically possible longevity.
Top 10 countries by life expectancy
| Country | Life Expectancy (both sexes), in years | Females Life Expectancy | Males Life Expectancy |
|---|---|---|---|
| 1. Hong Kong | 85.63 | 88.26 | 82.97 |
| 2. Japan | 84.85 | 87.88 | 81.83 |
| 3. South Korea | 84.43 | 87.28 | 81.32 |
| 4. French Polynesia | 84.19 | 86.62 | 81.90 |
| 5. Switzerland | 84.09 | 85.95 | 82.17 |
| 6. Australia | 84.07 | 85.85 | 82.28 |
| 7. Italy | 83.87 | 85.87 | 81.75 |
| 8. Singapore | 83.86 | 86.36 | 81.38 |
| 9. Spain | 83.80 | 86.44 | 81.10 |
| 10. Réunion | 83.67 | 86.45 | 80.67 |
(Data source link)
Physically active senior. Image credit: StockSnap, CC0 Public Domain
Wrapping up
Advances in public health, medical innovation, and living conditions have elevated the average life expectancy from around 30-40 years in the 1800s to over 70 years today, with some countries exceeding 80 years.
However, recent research suggests that pushing human longevity beyond certain natural limits, potentially between 120 and 150 years, may be biologically challenging. This assumption is based on a recent study which emphasized the fundamental differences between chronological and biological aging, showing that after a certain point, the body’s ability to recover from environmental stressors (such as harmful genetic mutations) weakens significantly.
Revolutionary medical treatments like gene therapy, regenerative medicine, and artificial intelligence could potentially further extend human life, but there are other obstacles to this process. As lifespans increase, issues related to the quality of life, healthcare access, and managing age-related diseases like dementia and frailty become more difficult to handle. The challenge is not just about living longer but ensuring those additional years are lived in good health.
