Human life expectancy is increasing. While the average life expectancy for someone born in 1960 was 52.5 years, the average life expectancy for someone born today is between 79 and 83 years. The question many of us are asking is: How far can we push the boundaries of the human lifespan?
If we compare today with the past 200 years, human life expectancy has increased exponentially:
- Thanks to immunizations, better nutrition, safer, cleaner living conditions, and advanced medical care, more children are surviving infancy and beyond the age of five.
- Thanks to reduced health inequalities and better public health initiatives, people who live to age 5 are more likely than their ancestors to live to old age.
However, the assumption that the maximum human life expectancy increases indefinitely is misleading.
As a BBC article puts it, “Overall life expectancy, which is [a] statistic […], hasn’t increased so much because we are living far longer than we used to as a species. It’s increased because more of us, as individuals, are making it that far.”
The authors of the article also attribute today’s safer environment, cleaner, and better living conditions to factors more important than modern medical advances that have contributed to extending the human lifespan. If a man who lived from 1200 to 1745 lived to be 21 years old and did not die by accident, violence, or poison, he could live an average of between 62 and 70 years, almost as long as a man today. In fact, humans may have reached the peak of our longevity. For the first time since 1982, life expectancy in the UK did not improve in 2015-2017, according to the Office for National Statistics.
We may not be extending human lifespans yet, but the good news is we can.
A 2017 article in Gerontology showed that although centenarian mortality has remained stable over the past few decades, this suggests that human lifespans stop increasing after a certain age. However, there is no convincing evidence that we have reached the limit of the human lifespan.
A new study by researchers at the University of Sapienza and the University of Rome has revealed a “mortality plateau” – where the risk of death stops increasing with age. The researchers collected records of every Italian aged 105 and older between 2009 and 2015 and found that after their 105th birthday, the odds of someone dying from one birthday to the next were about 50/50. If the future of human longevity is not predetermined, it will depend on human efforts to extend our lifespan.
A recent study by Stanford University biologist Shripad Tuljapurkar, published in the Proceedings of the National Academy of Sciences, found that the average age of death for people over 65 increases by three years every 25 years. This means that people can live an average of six years longer than their grandparents.
The same research shows that our efforts to extend the human lifespan have not been in vain. Previous studies put the human lifespan at around 115 years, but this date has been debated (and subsequently defended). Since then, we’ve also seen some people live longer.
What is NAD+?
NAD+ stands for Nicotinamide Adenine Dinucleotide. It is a coenzyme necessary for life and cellular activities required for the normal function and survival of the human body. Enzymes act as catalysts that make biological processes happen faster, while coenzymes are molecules that act as “helpers” for enzymes, enabling them to work properly. In the early 1900s, scientists first discovered NAD+ and began researching its benefits. But in recent years, we have begun to realize its full potential.
Because NAD+ plays an important role in many different biological processes, scientists and clinicians are currently investigating the many ways it can be used to help maintain organ health in people with age-related diseases.
What does NAD+ do?
As a “helper molecule,” NAD+ interacts with enzymes in the body, activating them and driving key cellular functions. In the human body, NAD+ has two roles: Helps convert nutrients into energy during metabolism. And act as helper molecules for proteins that control the activities of other cells. Furthermore, NAD+ is an important regulator in important processes such as DNA damage control and mitochondrial energy production.
Antiaging proteins called sirtuins are essential for various biological functions in the body. Sirtuins rely on NAD+ as a coenzyme to function effectively. Sirtuins are highly activated when NAD+ levels are elevated and help slow the aging process by controlling inflammation and DNA damage. Since NAD+ promotes sirtuin activity, sirtuins stabilize telomeres to maintain healthy telomere length. In addition, NAD+ promotes the activity of a protein called poly ADP ribose polymerase (PARP). PARPs are involved in DNA repair using NAD+. When NDA+ levels are high, PARP acts actively and affects the maintenance of healthy cells.
Mitochondrial energy production
Mitochondria are tiny organelles in cells that are considered “the cell’s powerhouse” because this is where the energy production process (called “cellular respiration”) takes place. Cellular respiration relies on the movement of electrons to generate energy. During this process, mitochondria break down glucose (the basic unit of sugar and carbohydrates in the food we eat) to produce energy.
Initially, glucose is converted into the cell’s energy molecule called adenosine triphosphate (ATP). NAD+ then acts as an electron carrier – it accepts electrons from metabolizing glucose and converts it into NADH (nicotinamide adenine dinucleotide hydride). During cellular respiration, NADH is converted back to NAD+, producing more ATP molecules in the process.
Why is NAD+ important?
NAD+ has attracted a lot of attention due to its abundance in the body and its vital involvement in the biochemical pathways that keep our bodies functioning. Due to its role in supporting efficient DNA repair, NAD+ is essential for the survival and the prevention of diseases caused or affected by DNA abnormalities. Some of these diseases include cancer, diabetes, cardiovascular disease, dementia, and decreased immune function. Since NAD+ is essential for energy production, a lack of NAD+ results in lower energy levels. As we age, our bodies produce less and less of this coenzyme. This explains why older adults are frail or do not have much energy to power their bodies and physiological processes.
Without NAD+, our bodies would not be as efficient as they should be, repair themselves less efficiently, and be prone to degenerative diseases. So what’s your opinion, will we live longer in the future?