Most of us will never escape the environmental factors at play.Credit: Westend61 via Getty Images ShareAging is one of the few things every living thing has in common. Humans, in particular, are living longer today than they did in the past. Much of this is due to societal advances such as vaccines, antibiotics, public health infrastructure, sanitation, hygiene, earlier diagnoses, and increased public awareness about health and longevity.Most people wont live to be 100 years old despite these leaps in public health, according to Briana Mezuk, the co-director of the University of Michigans Center for Social Epidemiology and Population Health.Five years after the beginning of the COVID-19 pandemic, the average life expectancies in the U.S. have decreased. For Indigenous Americans and Alaska Natives, life expectancy decreased by 6.6 years to 65.2, according to a 2023 analysis of provisional data from the National Center for Health Statistics. Life expectancy decreased by about four years for Black and Hispanic Americans to 70.8 and 77.7 years, respectively. Asian and white Americans saw a drop of roughly 2 years to 83.5 and 76.4 years.Everything has to have a limit. Theres no creature on planet Earth that we know of that doesnt die at some point, said Mezuk. But theres obviously substantial variation in life expectancy and healthy life expectancy, which is in some ways more important than the first question. How long can we live and be able to have the type of psychological, functional, and social life that makes life worth living? What is that life expectancy?Research maintains that the natural limit for human lifespan is about 122 years, based on the fact that the longest-living person died at 122 in 1997, and no one has been known to live longer.Truthfully, no one knows. But it will likely be shorter than the biological maximum that a human could live.And theres a difference between life expectancy and the rate of aging, explained William Mair, the director of the Harvard Chan School Aging Initiative. Many factors influence life expectancy in the United States. As people age, their susceptibility to chronic diseases like heart disease, various cancers, and diabetes increases. For younger folks, accidents, violence, and drug overdoses contribute heavily to early mortality. The life expectancy of all demographics is affected by income, education, access to healthcare, and other socioeconomic and systemic factors. When it comes to race, for example, systemic inequality routinely leads to adverse health outcomes. Even though advances in medicine and technology continue to extend lifespans, these factors, plus broader public health crises, such as the opioid epidemic and COVID-19, have underscored our ability to live longer.The rate at which the body ages, however, refers to the biological speed at which our bodies deteriorate over time due to cellular damage, genetic factors, and environmental influences.People get exposed to things that accumulate in the body, and the accumulation of those things makes it so, at some point, the bodys just not resilient enough to function, said Mezuk. Even if you imagine the person where they just live in a room and theyre locked there, and they never get any environmental exposures, theyll die just through biological processes. But for the rest of us who likely wont spend our lives in a literal bubble, well be exposed to things that alter how well our bodies agelike radiation from the sun or air pollutionsimply because were out and about living life.Some people try to lessen the impact of environmental factors on their lives through life extension fads and biohacking. This includes injecting themselves with NAD+ (an enzyme that promises anti-aging benefits), extreme dietary restrictions, plasma injections, hundreds of supplementsthe list goes on. The most extreme example is venture capitalist Bryan Johnson, who has become infamous for pursuing youth and immortality. The Netflix documentary, Dont Die, explains his journey in depth and, perhaps most interestingly, highlights a compulsive need to govern how long he can live.His means may be extreme, but the motive is understandable. That said, control is an illusion when it comes to this type of thing. While Johnson has millions of dollars at his disposal to experiment with a multitude of therapiesBloomberg estimates that he spends $2 million annually on doctors and treatmentsmost people dont. And a lot of what ages people are the circumstances they were born into and, due to socioeconomic and systemic factors, like poverty and racism, are increasingly difficult to escape. Get the Popular Science newsletter Breakthroughs, discoveries, and DIY tips sent every weekday. By signing up you agree to our Terms of Service and Privacy Policy.Someones location, for example, can define their outcomes and risk for chronic conditions. In the U.S., two people living just several miles apart could have dramatically different health outcomes and their bodies can age at dramatically different rates due to stress, access to healthcare, or nutrition. On the other hand, speaking of her time living in Italy, Mezuk noted that people who live in the Mediterranean exist within a society structured on longevity due to broader access to higher-quality foods, shops closing so people could cook their kids a healthy lunch at home, smaller portion sizes, and a better work-life culture. It is just built fundamentally differently on a different value system than we have in the United States, she added.When you think about life expectancy, what has really happened in the last 100 years, certainly in developed countries like the U.S. and increasingly across the world, is weve added a phenomenal amount of time to human life expectancy, said Mair. But those additional years have absolutely really nothing to do with making our bodies intrinsically age slower.Instead, the problem of aging has been shifted down the road. Alzheimers disease has increased, as have other age-related chronic conditions, due to people living longer. Now, many of us are living to our seventies; were experiencing this built-in obsolescence of humans that manifests itself in age-related chronic conditions, said Mair.Even still, the best balms against aging poorly are the things our mothers and grandmothers told us to do: exercise regularly, avoid smoking, avoid drinking too much alcohol, and stay away from highly processed foods to focus on a balanced diet of healthy whole foods.This story is part of Popular SciencesAsk Us Anything series, where we answer your most outlandish, mind-burning questions, from the ordinary to the off-the-wall. Have something youve always wanted to know?Ask us.