Few of us relish the thought of growing old. No matter how well we take care of ourselves, aging can bring unwelcome changes that are often painful and debilitating. Yet we are fortunate to have been born during a time when modern medicine can offer us a degree of comfort from our pain, and sometimes solutions to what ails us.
In centuries past, peoples’ lifespans averaged about 40 years, a discouragingly low number partially attributed to high infant mortality. A lot has happened to improve society’s health since then. Today, many consider 40 youthful. Some even postpone starting families until their fourth decade, following pursuit of an education, career development, or social experiences. In Massachusetts, you can now expect to live until 80. Children in Japan can anticipate reaching 85. Although COVID-19 threw us a curve ball, temporarily reducing our average age of death, we are back on the fast track of living longer.
What causes us to age?
Aging is characterized by many unwelcome changes, from shifts in the type and number of bacteria that live in our intestines to the degree of scarring on our DNA known as methylation. DNA is a molecule that contains our genetic information, and determines who we become. Our DNA is managed and organized by chromosomes. These cells contain all the DNA needed for our growth, development, and function.
Similar to the homes we live in and the cars we drive, over time our DNA undergoes wear and tear. As it becomes less spry, our genes may express themselves in a way that leads to disease. The mechanics leading up to this are varied. Our telomeres, the protective end caps of our chromosomes, shorten, and no longer protect our DNA. Our cells manufacture less of the energy-producing chemical ATP. They stop dividing, eventually becoming dormant, and they don’t communicate with one another as well, or respond to the nutrients we are ingesting. Nor do they effectively dispose of damaged materials that build up within them. In a nutshell, as our cells become exhausted, so do we! Despite the bleak-sounding prognosis, there are reasons to keep our chins up.
What progress is being made to delay aging?
The question of whether we can put an end to aging or, at very least, prolong our time here, is being pondered by a MIT research lab, and it’s producing some interesting and varied results. Some scientists say we’re nearing the ceiling of the age range our bodies can sustain; that aging consists of hundreds of different processes, and it’s a fool’s errand to pinpoint and devote research dollars to target just one. Others argue that we can move the needle closer to age 130, but beyond that, cells will start to break down regardless of the intervention. A few embrace a more optimistic framework, believing that advancing technology can pave the way to a fountain of youth. If sea creatures can live hundreds of years and the bristlecone pine can survive indefinitely, why can’t we?
Although not a panacea for age-related relief, there are some promising pharmaceuticals that the scientific community is keeping an eye on. Some are senolytic drugs that target and eliminate senescent cells that are not functioning properly and have stopped dividing. Rapamycin, a Food and Drug Administration–approved immunosuppressant, has extended the lifespan of worms and mice, and may have potential in human medicine. Metformin, a common diabetes medication, has been linked with reducing age-related diseases by countering inflammation and improving mitochondrial function. And NAD+, a molecule that helps regulate cellular energy production and repair, may one day help us delay age-related diseases. Human trials are underway with all of these drugs.
Animal studies are also offering a glimpse into the potential of longevity extension. One of them involves bats, a long-lived species which resists cancer and many other illnesses. Surprisingly, a bat’s ability to repair its damaged DNA increases with age. Lab evidence shows that mice, engineered with a bat gene, resist certain viruses.
Perhaps the most promising research lies in the field of epigenetics. Epigenetics focuses on the way genes express themselves, and may one day be used broadly to change this expression. By altering the chemical switches in a cell which turn genes on and off, researchers are able to rejuvenate aging animals. They have also successfully rejuvenated skin cells from elderly humans, and have discovered that cells can be reprogrammed to look and act like those in a newly formed embryo. While these efforts are applauded as a welcome first step, researchers learned that with too much tampering, cells lose their identity. This can trigger negative outcomes like tumor growth. But scientists remain optimistic that someday epigenetic reprogramming may prove to be the antidote needed to delay aging.
Although researchers are still at the starting gate, we’ve seen some applicable successes. From Duke University, an epigenetic editing technique is able to turn down the volume of a gene implicated in Parkinson’s disease. Another team lowered the cholesterol level in mice, and a biotech company is working on an injectable cocktail to silence the genes and start the rejuvenation process in the knees of osteoarthritis patients.
Should aging be classified as a disease?
Aging isn’t officially considered a disease. Rather, aging is considered a natural biologic process, during which specific diseases may occur. This distinction between considering aging as a “natural,” inevitable biologic process and an array of biologic processes that can be altered, a “disease,” has major implications.
Nir Barzilai, professor of medicine and genetics at Albert Einstein College of Medicine, demonstrated that centenarians have protective genes which help guard against age-related diseases. His research may help determine whether the diseases that strike us in old age are symptoms, not causes. He feels that unless we address aging at its root cause, we won’t make linear progress toward longer lifespans. By looking at aging as a disease, we can hone in on prevention and cure.
Reclassifying aging as a disease would also help to crack down on myriad antiaging products, many of which are laying false claim to their products’ benefits. Supplements have become a billion-dollar industry which is largely unregulated, and a reclassification would require manufacturers to pursue FDA approval, proving safety and effectiveness.
Yet not everyone is in the “aging as a disease” camp. One scientist says the war on entropy, or the dysregulation of cellular structures, is one we can’t win. Nonbelievers feel we shouldn’t be wasting valuable funding to pursue a nebulous and impractical goal; that we can never control the many internal processes involved in aging, and funds are best spent trying to protect the public’s health. Furthermore, treating aging as a disease might foster ageism and cast a negative light on growing old, steering us away from the pressing issues of remaining healthy and productive.
What can we do now?
While we wait for scientists to turn back our biological clocks, our most immediate solution may rest in changing our own behaviors, investing in practices that support good health. By focusing on our “health spans,” the length of time we remain healthy and free from serious or chronic diseases, we may feel better and live longer.
- Get regular medical checkups. Annual “wellness visits” for people on Medicare are free.
- Follow your practitioner’s advice. If you don’t want to do what they recommend, talk to them about it. They may offer you an alternative approach.
- Write your questions down before you have a medical visit. Include anything that worries you or is out of the ordinary. Sometimes little clues given to practitioners by patients can make a big difference in staying healthy.
- Stay active. Walk, swim, dance, get out of the house, socialize, use the resources of your senior center. Research shows that people who are more active live longer and better.
- Eat well. A diet balanced with adequate amounts of nutrients will serve you far better than one based on doughnuts, as delicious as they might be.
- Be wary of poor advice and scams that often appear on the internet and are advertised on TV. Look to the experts for advice. The National Institute on Aging has easy-to-understand recommendations on diet, health, and exercise for older adults.
