Since time immemorial, human beings have marked the passage of time. Our clocks tick by every second, reminding us to carpe diem, or seize the day, while we can.
Our lifespans, as it were, used to be relatively short. In the 1800s, life expectancies across the world were less than 40 years of age, but within the next 150 years, this was drastically raised by medical advances and increased prosperity. Fast forward to 2020 and global life expectancy is now 72.6 years – higher than any country in 1950.
Initially restricted to developed countries, population aging has become a trend in the developing world as well. However, with the rapidly advancing pace of science, one would be tempted to ask, how close are we to stopping aging? Can aging be reversed, or is the march of time inevitable?
The reverse ageing paradox
As people live longer, population aging becomes a greater economic problem, placing a burden on public health spending and decreasing productivity of the workforce. Aging is the fundamental driver behind many diseases rising in incidence across the world, such as cancer, heart disease, stroke, Alzheimer’s disease, and type 2 diabetes.
As one expert in population aging at the European Molecular Biology Laboratory, Halldór Stefánsson, explains: “Chronic degenerative diseases—that very few people lived long enough to experience in the past—have replaced infectious and parasitic diseases as the primary cause of death.” The question on all our minds is, ‘can science stop aging?’
Age reversal technology will be a reality soon. Our bodies will be kept biologically younger for longer, regardless of our chronological age.
The goal is to preventively target aging - the major risk factor for a wide variety of diseases and disabilities - instead of treating one disease at a time, which is very costly. One future model from the Office of Budget Responsibility projected an increase in NHS expenditure of £42 million year-on-year until 2031 due to the aging population.
Reverse aging technology would increase not only lifespan, but healthspan - the period of our life for which we are healthy, happy, and productive. It would continually restore vitality and bodily function by removing the damage that is inevitably caused by the processes of life.
|Benefits of reversing aging||Rate of disease|
|Type II Diabetes||⇩|
|Neurodegenerative disease (e.g., Alzheimer’s, Parkinsons)||⇩|
What is the normal human aging timeline?
Life in the human body takes place at microscopic level as each cell undergoes daily metabolic reactions. The side effects of these reactions accumulate over time and, after many years, eventually become toxic to the body, resulting in progressive decline, greater frailty, and eventually death.
The human aging timeline is also driven by interactions between our genes and the environment. Our genes may contribute up to a quarter of our predisposition towards natural longevity due to the increased presence of genes that alter cell metabolism and cell reproduction to favour slower aging.
Some developmental factors, such as perinatal conditions and birth weight, have also been found to have an impact. Smoking is thought to decrease longevity, not in the least because it increases the risk of several deadly diseases. Conversely, a diet rich in leafy greens may contribute to longer life expectancy.
Credible aging research, known as biogerontology or geroscience, should be distinguished from the commercial anti-aging industry – historically been rife with charlatanism.
There is no immortal elixir of life: a consortium of biogerontologists pointed out in 2002 that “no currently marketed intervention — none — has yet been proved to slow, stop, or reverse human aging, and some can be downright dangerous” - wise words for the mystified consumer.
However, this was more than 10 years ago. Right now, anti-aging therapies are in clinical trials. However, as of yet, none have achieved regulatory approval for mass, widespread use. To reverse the aging process in humans, we would need something safe, effective, and ideally not expensive – some therapies such as blood plasma transfusions would cost up to $8,000 USD a month if implemented.
Is it possible to reverse aging?
On the bright side, reversing the aging process is already possible for human cells and simple model organisms in scientific experiments. From yeast and worms, science has moved on to being able to extend the lifespans of rats, mice, and monkeys. So, extending lifespan and reversing aging is possible in small organisms, but not yet for humans.
Longevity studies in simple organisms
Cells, the smallest unit of life, are first produced as ‘stem cells’, from which they undergo a process of maturation, or ‘differentiation’, into specific cell types that perform specific functions. Think about an embryo - from a single cell, multiplication and differentiation produces a ball of cells that develops into a foetus with different organs.
In 2006, Shinya Yamanaka, a Japanese Nobel Prize-winning stem cell researcher, discovered that mature cells in mice that had already undergone this development could be reprogrammed to become stem cells by introducing just a few genes. These stem cells regained the ability to develop into all types of cells in the body. Today, regenerative stem cell medicine works by using these Yamanaka factors to perform a reverse ageing of cells.
A very simple organism, the nematode worm, serves as a basic model for life span extension experiments. At least six different mechanisms are known to achieve this effect. Interventions applicable to humans include calorie restriction, a less severe form of which is intermittent fasting, already practiced by many.
Other things that worked include targeting molecular proteins, such as Ins/IGF-1, that are involved in the signalling processes in our body responsible for aging. Reducing this signalling could be achieved by using drugs that inhibit these proteins, or through changing the worm’s genetic signature. The complete deletion of genes responsible for aging increased the lifespan of these worms by six times in one study.
Another landmark study in 2005 opened new doors in aging research when scientists surgically joined the circulatory systems of two mice, one old and one young. When the blood of these two mice mixed, the old mouse became younger, while the young mouse prematurely aged.
The old mouse was able to heal wounds more efficiently, and the GDF11 protein was identified as a possible substance to restore the muscles of old mice to their youthful strength.
However, the role of GDF11 was disputed by another study later on. In addition, the less complex the organism, the easier it is to extend their life - the human body is much more complex than a mouse’s, meaning that any interventions to reverse aging will have a smaller effect in humans than they do on mice.
Disease prevention for longevity in humans
While reversing aging is still a new science, knowledge is power, and predicting your overall health and risk of various diseases based on your DNA or your microbiome is a good option for the cautious reader. The Atlas DNA Test is able to check for your predisposition to common diseases and provide personalised recommendations to lower your risk of illnesses that could shorten your lifespan.
As people age, their immune systems get less effective, increasing the risks of infection while decreasing the body’s ability to fight infections and heal wounds. Interestingly, the flu vaccine has been shown not to work in older people because old immune systems cannot produce the necessary response to make the vaccine effective.
However, a pharmaceutical company has recently found that a compound called everolimus improved the effectiveness of the flu shot in people older than 65. Tests showed that the compound had rejuvenated the immune systems of these old people. This compound is currently under further investigation.
How can we reverse aging in our daily lives?
While waiting for the scientists to figure it out, there are some simple changes you can make that might help reverse ageing, or at least reduce your risk of an early death by common, but fatal, diseases.
Is it possible to reverse aging with exercise?
Some evidence suggests yes. A comparison of healthy older adults (cyclists who had exercised most of their lives) with those who didn’t exercise, showed that age-related loss of muscle mass and strength did not occur in those who exercised regularly. Furthermore, the cyclists’ body fat and cholesterol levels did not rise with age, and their immune systems were younger.
This is relevant for ageing studies because elderly people have low muscle mass – this affects mobility and increases the risk of dangerous falls and fractures. Meanwhile, high cholesterol and body fat increase the risk for heart disease, stroke, and diabetes, common diseases in old age. As we previously mentioned, an older immune system is also less effective than a young immune system, which is why even common infections pose a more serious risk for the elderly.
Intermittent fasting to prevent aging
Caloric restriction of 10-40% has consistently been shown to increase lifespan in mice and primates. In humans, a 2-year study with up to 12% caloric restriction decreased the risk of diabetes, heart disease, and stroke with no side effects on libido, mood, sleep, and quality of life. Rare, but significant, side effects included bouts of anaemia and loss of bone density (which, the scientists suggested, could be counteracted with exercise).
Caloric restriction is too harsh for most people, so intermittent fasting, a milder alternative, has become popular. While there are several methods to practice it, the author wishes to highlight proven ways to stay healthy into old age, even if not necessarily reversing ageing:
- Eat a balanced and nutritious diet.
- Drink alcohol in moderation or avoid it altogether.
- Don’t smoke.
- Maintain an active social lifestyle.
- Sleep at least seven hours per night.
Do supplements work?
Some companies are developing supplements that may help to reverse aging by providing beneficial molecules in large quantities. One interesting molecule in this field is nicotinamide riboside, which is converted inside the body into NAD+. In normal conditions, levels of this compound decline in the body as we age, but it may become a therapeutic strategy in the future to help protect against aging.
However, there are many unverified anti-aging supplements, creams, and products on the market that promise miracle results. These supplements are not strictly regulated, especially in comparison to pharmaceutical drugs. While generally less potent, they can also be adulterated, ineffective, and sometimes dangerous. That’s why, whenever possible, we should choose lifestyle improvements over (potentially expensive) supplements.
Conclusion: Is reverse aging possible?
So, here’s the lowdown: can scientists reverse aging? In 2020, the answer is not yet, although clinical trials have begun for regenerative stem cell therapies in degenerative diseases, such as heart failure. In the future, many organs may be grown from cells of a single organ donor, alleviating the organ shortage for transplants, and the long waiting lists for patients.
However, such technology is still some way from reaching the supermarket shelves. Many of the stem cells used are embryonic stem cells, taken from unfertilised embryos sourced from IVF (in vitro fertilisation) clinics - giving these cells a second purpose has a positive impact but is still controversial for members of the public.
While reversing aging at a cellular level is attractive, it is not yet known whether this could, in the long-term, lead to cancer, a disease in which individual cells reproduce uncontrollably and become effectively immortal.
In future there may be anti-aging pills we can take as a preventative medication to prolong longevity, but it will be decades before we fully understand the effect of these pills and interventions. Should a reverse aging process become possible, it may drastically alter our perception of illness and aging, and ultimately, our perception of time itself.
- H. Stefansson, The science of ageing and anti-ageing, 2005
- J Fishman et al., Anti-aging science: The emergence, maintenance, and enhancement of a discipline, 2012
- Scientific American, Researchers Study 3 Promising Anti-Aging Therapies, 2015
- Harvard News Edu Gazette, Longevity and anti-aging research: ‘Prime time for an impact on the globe’, 2019
- Science Daily, A lifetime of regular exercise slows down aging, study finds, 2018
- D Melzer et al., The genetics of human ageing, 2020
- CY Shen et al., Anti‐ageing active ingredients from herbs and nutraceuticals used in traditional Chinese medicine: pharmacological mechanisms and implications for drug discovery, 2017
- JP de Magalhaes et al., The Business of Anti-Aging Science, 2017
- Extending Life-Span in C. elegans, 2004
- Health Information, Calorie Restriction and Fasting Diets: What Do We Know?
- Michael Caley & Khesh Sidhu, Estimating the future healthcare costs of an aging population in the UK: expansion of morbidity and the need for preventative care, 2010
- Max Roser et al., Life Expectancy, revised 2019
- MA Otto, MMWR: Current flu vaccine does not protect elderly, 2018
- CJ Sleeves et al., Ageing, Genes, Environment and Epigenetics: What Twin Studies Tell Us Now, and in the Future, 2012