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Chronic diseases such as cancer, heart disease, and diabetes often affect individuals in their 60s and beyond. The average age for a cancer diagnosis is 66, while men typically experience their first heart attack at 65 (women become equally at risk after menopause), and Type 2 diabetes commonly appears between the ages of 45 and 64. As these diseases are diagnosed, doctors focus on managing and controlling them rather than finding a cure. Consequently, individuals spend a significant portion of their lives in declining health, battling chronic illnesses for a substantial proportion of that time.
Many people first encounter chronic illnesses through their parents, as aging Americans now live longer but with more diseases compared to previous generations. If one disease is managed, another may emerge, leading researchers to believe that even curing cancer may only add around three years to a person’s life before another disease arises. After the age of 65, most individuals have two or more chronic diseases, and adults in their 60s and 70s may be prescribed up to five different medications simultaneously. However, what benefits one condition may worsen another, complicating the treatment process.
As the average life expectancy in the US is around 76 years, it is likely that individuals will ultimately succumb to one of these chronic diseases. The current healthcare system primarily focuses on treating individual diseases once individuals become sick, rather than taking a preventative approach. This reactive approach is akin to waiting for an aircraft to break down at 35,000 feet before attempting to fix it, rather than conducting preventative maintenance while it is on the ground.
Pushing Back Diseases
All chronic conditions associated with aging share a common risk factor: age itself. Aging processes make individuals more susceptible to these diseases, affecting both their health span (how long they stay healthy) and life span (how long they live). As people age, they experience a loss of strength and mobility due to molecular changes that gradually undermine the body’s integrity and resilience. Scientists refer to these changes as “hallmarks,” which include chronic inflammation and the accumulation of senescent cells (also known as “zombie” cells). Senescent cells cease multiplying due to damage or stress but do not die as they should.
Some researchers believe that by addressing aging itself, it may be possible to delay or even prevent age-related diseases, allowing individuals to live healthier and longer lives. Exercise is one intervention that can influence the biology of aging and is accessible to almost everyone. According to a study published in the Journal of the American Medical Association Internal Medicine in 2020, individuals who are physically fit, exercise regularly, refrain from smoking, and consume minimal alcohol can expect to gain an additional nine years without chronic diseases compared to those with unhealthy lifestyles.
While diet and exercise are currently the best interventions available, the field of longevity research, also known as geroscience or anti-aging, is still in its early stages. Several drugs show promise in postponing or preventing the onset of debilitating diseases. Animal studies have demonstrated their potential, and clinical trials are now underway to assess their effectiveness in humans.
Rapamycin: A Promising Drug
One such promising drug is rapamycin, an antifungal medication approved by the FDA as an immune suppressor to prevent organ rejection in transplant recipients. Rapamycin inhibits a protein called mechanistic target of rapamycin (mTOR), which regulates various cellular processes in response to nutrient availability. Studies have shown that administering rapamycin to yeast, worms, flies, and mice can extend their lifespan. Researchers have also explored the anti-aging effects of rapamycin in humans, with studies suggesting that it can improve immune function in older adults, enhancing their response to flu shots and reducing their risk of severe illness during cold and flu season.
Rapamycin does not kill senescent cells, but it does silence their inflammatory signals, effectively putting a gag on them. This treatment has the potential to improve multiple age-related diseases simultaneously. Matt Kaeberlein, a biogerontologist at the University of Washington and chief science officer of Optispan, is leading a rapamycin trial in dogs, which experience similar age-related decline as humans but have much shorter lifespans.
While studies in mice have indicated that rapamycin may have beneficial effects on age-related cognitive decline, heart function, ovarian health, and periodontal disease, it is important to note that mice differ significantly from humans. Mice do not develop heart disease or Alzheimer’s disease, which are major killers in older humans. Clinical trials have been initiated to test the effects of rapamycin in humans, but there are many challenges in conducting these trials, as it can take decades to determine the drug’s impact on health span due to the slow aging process in humans.
Targeting Zombie Cells
As individuals age, their immune function undergoes both decline and escalation. While the immune system becomes less responsive to pathogens, it can also become overactive and attack healthy tissues and organs, leading to chronic inflammation associated with various age-related diseases.
Senescent cells, also known as “zombie” cells, accumulate as people age and emit inflammatory signals that contribute to age-related diseases. Rapamycin silences these signals, but another promising approach involves senolytic drugs, which seek out and kill senescent cells directly. Several ongoing efforts are testing senolytics in the treatment of age-related diseases such as macular degeneration, diabetes, obesity, and Alzheimer’s.
These are just a few examples of the many strategies being pursued to target different aspects of aging. Numerous companies in the longevity biotech sector are working to translate the findings from animal studies into human treatments. Investment in this field has been growing, with companies like Calico (backed by Google) and Altos Labs (backed by Jeff Bezos) receiving millions in funding.
Learning from the Healthiest
Some individuals age more slowly than others, remaining physically and mentally sharp well into old age. By studying the biology of these exceptional individuals, researchers hope to gain insights that can help others live longer and healthier lives. BioAge, a biotech company, utilizes artificial intelligence to analyze the distinctive molecular features of individuals who experience the healthiest and longest lives. This knowledge is then applied to the development of therapies that could potentially extend the health span of the general population.
BioAge is currently testing a drug for muscle atrophy, a common age-related condition characterized by the loss of muscle mass. As individuals age, they lose approximately 3% to 5% of muscle mass per decade after the age of 30, with men typically losing around 30% of their muscle mass over their lifetimes. Muscle loss increases the risk of falls, which are a leading cause of accidental death in older people. BioAge has already demonstrated that its drug can prevent muscle atrophy in elderly individuals on bedrest and is now progressing to the next phase of clinical trials.
The Panacea for Immortality?
While the field of longevity research holds great promise, it is important not to expect miraculous results overnight. There is no single “silver bullet” drug that can add 50 years to a person’s life. However, BioAge’s CEO, Kristen Fortney, believes that adding an additional 10 to 20 years to the average health span could be achievable in the near future with the advancements currently being made.
Instead of waiting for symptoms to occur and suffering to set in, a shift towards a preventive model of care may be necessary. This would involve proactive monitoring of patients and the use of medicines prescribed based on blood tests that indicate the speed of aging and the individual’s susceptibility to specific age-related diseases. Rather than treating diseases reactively, a preventive approach could delay the onset of future illnesses and potentially avert them altogether.
The current healthcare system has been successful in keeping sick individuals alive, but it has not prioritized keeping people healthy for longer periods. The ultimate goal should be to maintain the highest quality of life for as long as possible by prioritizing preventive measures and delaying age-related diseases.
As the discussion on the use of longevity drugs in healthy individuals continues, it is essential to involve experts from various fields, including geroscience, the National Institutes of Health, the Centers for Disease Control and Prevention, and other federal agencies. Determining the acceptable level of uncertainty and risk in healthy individuals will be crucial in moving forward with the development and implementation of preventive interventions.
In conclusion, the field of longevity research holds tremendous potential for helping individuals live healthier lives for longer periods. While there are challenges to overcome, such as conducting lengthy clinical trials and securing funding for basic research, the progress being made in understanding the biology of aging and developing potential interventions is promising. By addressing aging itself and targeting the hallmarks of aging, it may be possible to delay or prevent age-related diseases, allowing individuals to enjoy extended periods of good health.