As we get older, many changes happen to our body, we become frail, our hair turns white, and our skin wrinkles. We also become more susceptible to disease and may lose our cognitive abilities.
Aging is generally considered an inevitable part of life, but can it be delayed, prolonging our youthful years? We asked 8 experts the question, 'Can aging be delayed?' Interestingly, there was a 75 percent 'likely' consensus. Here is what we found out.
What is aging?
All living things are made of cells. Scientists often grow cells in the lab to study them. In 1961, researcher Leonard Hayflick noticed that, on average, a human cell can only divide 50 times before it goes into a hibernation-like state called 'senescence'. It is thought that an accumulation of senescent cells in tissues of the body could damage other cells and play a crucial role in aging.
There are many causes of aging and senescence at the cellular level. These include oxidative damage, accumulations of small errors in DNA, and the shortening of telomeres. Essentially, different components of the cell go through general wear and tear throughout the cell's lifetime. At some point, this damage means the cell can no longer function as it used to.
Can we delay aging in cells?
Whilst Hayflick noticed that normal human cells had a finite lifetime, some cells are able to multiply indefinitely. These cells are normally from cancers or have been genetically modified. By changing certain pathways in cells, such as how they multiply or the maintenance of telomeres, we can overcome the normal process of aging.
Aging can therefore be delayed in cells and is routinely done so to aid research. Importantly, however, these cells are not the same as the healthy cells you would find in the human body.
Can we delay aging in animals?
Genetic manipulation can not only delay aging in cells but also in whole animals (also called 'model organisms'). Experiments to delay aging started in the nematode worm C. elegans. Due to how easy these animals are to work with in the laboratory, scientists have found a whole range of pathways that can be tinkered to delay aging.
Interestingly, one of these pathways is connected to metabolism and diet. Restricted diets have been found to delay aging in a whole range of animals, from flies to monkeys to dogs. The restricted calorie intake might prompt the cells in the body to go into a 'protective' mode, which slows down aging.
Dr Gerardo Ferbeyre, an expert in anti-aging from Montreal University, points out that "[a]lthough not everything that works in model organisms will likely work in humans, some of the ideas coming from aging research may eventually lead to anti-aging therapies."
Can aging be delayed in humans?
Professor Janet Thornton, an expert in anti-aging from the European Bioinformatics Institute, highlights that "[i]n humans, it is not ethical to perform mutations, and there are so many conflicting forces at work that it is difficult to assess the impact of dietary restrictions. In the lab, worms' life span can be increased 10-fold; in flies and mice, the max increase is just 1.5 fold, but an equivalent measure is not available in humans. It is likely that the human system is complex with many interconnections and buffering, so such extensions may not be accessible."
Dr Marco Demaria from the Groningen University says, "We have several lifestyle interventions clearly influencing onset and progression of aging (diet and exercise at the top of the list)." Many of the other experts suggested improving diet and exercise in order to delay aging. People who do regular exercise and live healthy lifestyles are usually more mobile and enjoy a higher quality of life when they get older.
Whilst aging is still likely inevitable for all living things, it is possible to delay it in cells and animals experimentally. For us humans, the best way to delay aging is to eat a balanced diet and do regular exercise.
Article based on 8 expert answers to this question: "Can aging be delayed?"