Effects of Aging: Can They Be Reversed?
In simple terms, aging is defined as the process of becoming older, which involves a number of biological mechanisms that lead to deterioration of health â€“ both cognitive and physical â€“ over time.
Of course, aging is inevitable. While many of us would like to stop the clock and avoid blowing out those birthday candles â€“ an unsubtle reminder that we are another year older â€“ it is beyond the realms of medical science.
What may be within reach one day, however, are ways to reduce or reverse the effects of aging, and weâ€™re not talking about anti-aging face creams or cosmetic surgery.
Increasingly, studies have focused on strategies that could combat aging at its core â€“ the cellular processes that contribute to age-related diseases and changes in our physical appearance as we become older.
In this spotlight, we explore the biological causes of aging, investigate what strategies researchers are proposing to fight the effects of aging, and look at what you can do to boost your chances of healthy aging.
The genetic aging theory
Many researchers believe the effects of aging are a result of numerous genetic and environmental factors, and these effects vary from person to person.
The genetic aging theory suggests that, just like hair color and height, our lifespan is influenced by the genes we inherit from our parents.
Such a theory may ring true; studies have shown that children of parents who have a long lifespan are more likely to live a longer life themselves.
The team found that female mouse models passed mutations in mitochondrial DNA â€“ which they accumulated through environmental exposures during their lifetime â€“ to offspring, which reduced their lifespan.
But while evidence for the genetic aging theory is strong, the fact remains that healthy aging and longevity is largely influenced by our environment â€“ that is, what we eat, how much we exercise, where we live and the compounds and toxins we are exposed to throughout our lifetime.
Oxidative stress and telomere length
Our DNA accumulates damage from environmental exposures as we age. While cells are capable of repairing most of this damage, sometimes it is beyond repair.
This most often occurs as a result of oxidative stress, where the body does not possess enough antioxidants to fix the damage caused by free radicals â€“ uncharged molecules that cause DNA damage. Oxidative stress has been identified as a key player in the aging process.
Another major cause of DNA damage is the shortening of telomeres. These are the caps at the end of each DNA strand that protect our chromosomes â€“ the thread- like structures that contain all our genetic data.
Telomeres naturally shorten as we age, reducing in length each time a cell divides. But when telomeres become too short, they are no longer able to protect the chromosomes, leaving them susceptible to damage that can lead to premature aging and disease development.
A recent study from the UKâ€™s University of Cambridge suggests that telomere shortening as a result of environmental exposures may even be passed to offspring.
The team found that rats that had lower oxygen in the womb during pregnancy â€“ often caused by smoking during pregnancy in humans â€“ gave birth to offspring with shorter telomeres than rats that had higher oxygen exposure.
What is more, the oxygen-deprived offspring were found to have abnormalities in their blood vessels â€“ a sign of faster aging and a predisposition to heart disease.
The evidence for telomere length as a major player in the aging process has become so strong that researchers are looking to use telomeres as a biomarker for age-related diseases.
Last year, for example, ishonest reported on a study in which researchers revealed how a distinct telomere pattern in the blood could be used to predict cancer development.
But what if researchers found a way to extend telomere length to protect against age-related diseases and the other effects of aging? Or what if they identified a strategy that could protect against oxidative stress?
Such approaches may not be too far from reality.
Extending telomere length to slow aging
By applying three applications of the modified RNA to human cells in a lab, they found they could increase the length of telomeres by around 1,000 nucleotides â€“ around 10% â€“ in a matter of days.
Blau and colleagues said their findings bring us a step closer to combatting both age-related and genetic diseases.
â€œOne day it may be possible to target muscle stem cells in a patient with Duchenne muscular dystrophy, for example, to extend their telomeres. There are also implications for treating conditions of aging, such as diabetes and heart disease. This has really opened the doors to consider all types of potential uses of this therapy,â€ says Blau.
But according to other research, there may be ways in which we can extend telomere length ourselves in order to slow the aging process.
From studying more than 4,600 healthy, middle-aged women, the team found that those who had greater adherence to a Mediterranean diet had longer telomeres than those with lower adherence to the diet.
Eradicating mitochondria to rejuvenate aging cells
Last month, Dr. JoÃ£o Passos, of the Institute for Aging at Newcastle University in the UK, and colleagues revealed a new strategy that they say could reverse the aging process: removing mitochondria from cells.
Mitochondria are described as the â€œpowerhousesâ€ of cells, giving them the energy to function, but previous research has also associated mitochondria with oxidative stress.
They found that eliminating mitochondria from the aging cells triggered a rejuvenation process, reducing markers of cellular aging to levels that are normally seen in younger cells.
Reversing brain aging
When it comes to aging, one of the biggest concerns is how it will affect our cognitive function.
The majority of people will see a decline in cognitive skills as they age. This is because certain areas of the brain â€“ particularly those linked to learning and memory â€“ shrink as we get older, interfering with connections between nerve cells.
Others may experience a more severe form of cognitive decline, such as Alzheimerâ€™s disease, which affects around 5.1 million adults aged 65 and older in the US, though this condition is thought to be triggered by the build-up of plaques and tangles in the brain, rather than brain shrinkage.
The team â€“ from the University of California-Irvine â€“ gave 11 rats a drug called ampakine every day for 3 months, while a further 12 rats received a placebo.
From brain scans conducted during treatment, the researchers found â€œmiddle-agedâ€ rats in the placebo group had shorter dendrites â€“ branch-like fibers that aid brain cell communication â€“ and fewer dendritic branches than the â€œadolescentâ€ rats that received the placebo.
The middle-aged rats that received ampakine, however, were found to have dendrites and dendritic branching that was comparable to those of the adolescent rats, suggesting that ampakine may be a promising compound for reversing brain aging.
â€œThere is a tendency to think that aging is an inexorable process, that it is something in the genes, and there is nothing you can do about it. This paper is saying that may not be true.â€
Eat well and exercise to reduce the effects of aging
While medical research certainly seems to be on the verge of finding promising strategies to reverse the aging process, it is likely to be a long time before telomere-lengthening medications hit the market.
But in the meantime, there are a number of things we can do to help reduce the effects of aging.
It goes without saying that regular exercise is good for health, but numerous studies have hailed exercise for its beneficial impact on aging.
The National Institute on Aging recommend following a diet that includes fruits, vegetables and grains â€“ particularly whole grains â€“ low-fat or fat-free dairy products, seafood, lean poultry and meats. They also recommend limiting the amount of saturated and trans fats, as well as levels of cholesterol, salt and added sugars.
Worried about those wrinkles?
When it comes to healthy skin aging â€“ and reducing the appearance of those dreaded wrinkles and brown spots â€“ the American Academy of Dermatology offer some advice:
- Protect your skin from the sun: ultraviolet radiation damages the skin fibers over time, causing it to lose its elasticity
- Avoid smoking: smoking speeds up skin aging, causing wrinkles and a dull complexion
- Eat a healthy diet: consuming lots of sugar and other refined carbohydrates has been linked to premature skin aging
- Limit alcohol consumption: alcohol dehydrates the skin, causing damage over time
- Cleanse skin gently: scrubbing your skin can speed up skin aging; wash your skin gently to remove makeup and pollution
- Use facial moisturizer daily: moisturizer keeps the skin hydrated by trapping water inside, promoting a youthful appearance.
As French fashion designer Coco Chanel once said:
â€œNature gives you the face you have at 20; it is up to you to merit the face you have at 50.â€
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