Americans today live roughly twice as long, on average, as they did when the Declaration of Independence was signed.

When the nation was founded in 1776, life expectancy was around 35 to 40 years old, historians estimate. However, someone who survived childhood in colonial America often lived into their 60s or even 70s.

Today, the average lifespan is about 79 years old, according to data from the Centers for Disease Control and Prevention.

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The improvement in lifespan over the centuries has been largely attributed to reduced deaths in infancy and from infectious diseases, multiple researchers have stated. Advances in sanitation, clean water, nutrition, vaccination and medical care have also contributed to lower mortality rates.

“Much of this vast discrepancy is related to the extremely high rates of infant, childhood and maternal mortality,” Dr. Omer Awan, physician and professor at the University of Maryland School of Medicine, told Fox News Digital.

“Childbirth was dangerous, and without antibiotics and vaccines, many infectious diseases, such as measles, smallpox and pneumonia, were deadly,” he went on. “Now we have cleaner water and sanitation, vaccines and antibiotics that have significantly prolonged life.”

Advances in treatments of chronic diseases such as high blood pressure, cancer and diabetes have also significantly prolonged life, the Harvard-trained doctor noted.

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According to the CDC, improved prevention and treatment of high blood pressure has helped reduce deaths from heart disease and stroke, two of the nation’s leading causes of death.

Mia Kazanjian, MD, a Stanford-trained body and breast radiologist with an interest in longevity who is based in Greenwich, Connecticut, attributes the shorter life expectancy in the 1700s to suboptimal sanitation, poor hygiene and limited medical treatments.

“Many babies and children died from infections like dysentery, diphtheria, scarlet fever and pneumonia,” she told Fox News Digital. Children who survived into adulthood often succumbed to infections like tuberculosis, cholera and typhoid fever.

Maternal mortality has also fallen dramatically over the past century due to advances in antibiotics, blood transfusions and safer obstetric care, according to the CDC.

Milestones in public health

Kazanjian pointed to several key advancements over the centuries that contributed to longevity improvements, including the development of early municipal water systems that provided cleaner drinking sources.

“Sewer system networks were built, the first in Brooklyn in 1857,” she said. “These allowed people to drink clean water and dispose of waste. Indoor plumbing with toilets and bathrooms became more widespread.”

“Without antibiotics and vaccines, many infectious diseases, such as measles, smallpox and pneumonia, were deadly.”

At this time, people’s understanding of disease started to improve, and public health measures were developed to minimize risk.

During the late 1800s, germ theory became widely accepted in medicine and public health, helping shape the Sanitary Era, the expert said.

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“The Federal Quarantine Act of 1878 allowed the government to prevent spread of infection from out of the country, from epidemics like yellow fever,” she said. “Food safety regulations went into effect in 1906, when the Pure Food and Drug Act and Federal Meat Inspection Act were passed.”

By 1900, the average life expectancy was about 49 years old, according to the National Vitals Statistics Report.

Another major landmark in increasing lifespan came with the development of vaccines and antibiotics to prevent and treat disease, Kazanjian noted.

“Jenner developed the smallpox vaccine in 1796, Pasteur created vaccines for rabies and anthrax in the 1880s, and several scientists created vaccines for polio, measles, influenza, mumps and rubella in the mid 1900s,” she said.

“Antibiotics proliferated in the 1940s, specifically penicillin and tetracycline. By 1950, the US life expectancy was about 68 years old.”

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From the mid-20th century to 2014, life expectancy continued to rise, Kazanjian said, largely due to “major gains” in medical knowledge of ways to prevent heart disease and stroke.

Public health campaigns promoting smoking cessation also played a role, as declining smoking rates helped reduce deaths from lung cancer, heart disease and stroke, according to the CDC.

“Motor vehicles became safer and carseats became staples,” Kazanjian noted.

According to the National Institutes of Health, advances in emergency medical services and trauma care have substantially reduced deaths after serious injuries.

Development of pharmaceuticals for cardiovascular disease and cancer also contributed to longer lives, according to Kazanjian.

Today’s longevity challenges

Modern longevity is more focused on preventing chronic disease and less about surviving childhood infections, noted Nneoma Oparaji, MD, a triple board-certified media physician specializing in obesity, lifestyle and internal medicine.

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“The next frontier will be less about living longer, but more about living healthier longer,” Houston-based Oparaji told Fox News Digital.

Kazanjian pointed out that between 2014 and 2026, there has been a fall and a rise in lifespan.

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“The fall was due to young adult deaths from drug overdoses, particularly the opioid epidemic, suicides and alcohol-related deaths,” she told Fox News Digital.

The COVID-19 pandemic reduced U.S. life expectancy by more than two years between 2019 and 2021 before it began recovering, CDC data shows.

Although U.S. life expectancy has rebounded since the pandemic, it remains below that of other high-income countries, largely because of higher death rates from chronic diseases, substance use and other preventable causes, according to KFF.

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Obesity rates also continue to climb, contributing to higher numbers of cardiovascular disease, diabetes and cancer, Kazanjian said.

“Most concerning is the rise in obesity in children,” she added.

“The next frontier will be less about living longer, but more about living healthier longer.”

Changing cancer trends are also affecting lifespan among younger adults, data shows.

“My generation, the millennials, has seen an unprecedented rise in young adult cancers, particularly colon and breast,” Kazanjian said, citing factors that include sedentary lifestyles, poor diet, alcohol, obesity and smoking, among others.

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The doctor said she aims to raise public health awareness of ways to improve lifespan.

“We need to get off our screens, move around more, eat a whole food, plant-based diet, sleep seven hours a night, do our screening exams, and avoid toxins like alcohol and cigarettes.”

We are officially living in the “maxxing” era.

From “looksmaxxing” to improve appearance to “sleepmaxxing” for better rest, these viral terms all point to the same goal: squeezing every ounce of potential out of a specific trait or habit.

With a growing focus on optimizing wellness and maximizing longevity, the trend has evolved into what’s known as “humanmaxxing,” sparking a bigger question: How far can people go to optimize the human body?

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While there is no single definition of humanmaxxing, the trend generally refers to efforts to optimize health, performance and longevity through a combination of lifestyle habits, health tracking, supplements and, in some cases, more experimental interventions.

For some, the movement begins with biohacking. According to Dave Asprey, a Texas-based wellness expert who refers to himself as the “father of biohacking,” optimizing your body starts with changing your environment.

Asprey has defined biohacking as “the art and science of changing the environment around you or inside you so that you have full control of your own biology.”

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His public advice focuses on boosting cellular energy through everyday choices like intermittent fasting, high-fat diets, red-light therapy and supplement routines.

“My goal right now is 180 years, because I’m doing something about it now instead of waiting,” he once said.

Others have embraced a more data-driven approach. Tech entrepreneur Bryan Johnson, creator of the multimillion-dollar longevity project Blueprint in Los Angeles, argues that optimizing the body means removing human error from health decisions and instead relying on medical data.

“Methodically, we sought to build an algorithm with science and data that could better care for me than I can myself,” Johnson wrote on his website. “My mind did not have the authority to override the algorithm.”

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Johnson’s routine involves tracking hundreds of health metrics, eating a precisely measured diet, taking dozens of supplements, and undergoing advanced medical treatments in an effort to reduce his biological age.

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At the far end of the spectrum are those investing in technologies aimed at pushing the limits of human performance.

London-based tech investor Christian Angermayer recently described humanmaxxing as a strategy toward human maximization.

“I don’t think we should become something different, because I think humans are awesome, but I think we can maximize the potential [that] is already in us,” he said in an interview with The New York Times.

Angermayer’s investment firm, Apeiron Investment Group, focuses on technologies intended to help people “live longer, healthier and more fulfilling lives.” He also founded atai Life Sciences, a biotechnology company that develops psychedelic treatments for mental health conditions that are currently being evaluated in clinical trials.

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As interest in humanmaxxing grows, mainstream health experts urge consumers to separate evidence-based wellness practices from experimental interventions.

Public guidance from the National Institute on Aging notes that while some anti-aging therapies have shown promise in laboratory research, there is not yet sufficient evidence that they can safely extend human life.

Clinical experts also caution that extreme self-experimentation can bypass the rigorous safety standards applied to conventional medical treatments.

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According to the Endocrine Society, taking substances such as testosterone or growth hormone without a medical need can lead to serious health risks, including cardiovascular complications and long-term disruption of the body’s chemical balance.

While many humanmaxxing habits overlap with standard healthy lifestyle practices, experts say consumers should be cautious of expensive or experimental interventions that promise dramatic anti-aging or longevity benefits without strong scientific evidence.

A new test could make it easier to detect high-risk prostate cancer cases earlier.

The blood test, called Stockholm3, is showing promise in clinical trials, beating out the traditional, standard prostate-specific antigen (PSA) test.

In a new study published in the Annals of Internal Medicine, researchers from the Karolinska Institutet in Sweden studied the test’s efficacy in more than 12,000 men — mostly Swedish or European — aged 50 to 74.

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All participants were tested with PSA and Stockholm3 and were followed for two years. During the follow-up period, 443 men were diagnosed with aggressive prostate cancer.

Stockholm3 detected 90% of aggressive prostate cancer cases compared to 74% for PSA tests.

Stockholm3 missed “significantly fewer” serious cancer cases than PSA. The number of men incorrectly classified as high-risk was similar across both tests, according to a press release.

Thorgerdur Palsdottir, a researcher at the Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, wrote in a statement that one of the major challenges in prostate cancer is being able to identify the cases that are “truly dangerous.”

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“Our results show that Stockholm3 identifies significantly more aggressive cancer cases than PSA without increasing the number of unnecessary follow-ups,” she said.

“These results point toward a potential change in how prostate cancer screening can be conducted,” the researcher added. “A more precise blood test could enable earlier detection of aggressive disease while reducing the number of unnecessary follow-up examinations and procedures.”

Study co-author Hari Vigneswaran, chief medical officer of Stockholm3-maker A3P Biomedical, commented on these “promising” findings in an interview with Fox News Digital.

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He confirmed that the PSA has been the standard for prostate cancer screening since the 1990s despite its “well-documented limitations.”

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“It leads to invasive and costly follow-up testing, contributes to over-diagnosis of non-aggressive cancers and, most importantly, it misses a substantial share of aggressive disease,” Vigneswaran said.

When aggressive prostate cancer is found while still confined in the prostate, the five-year survival rate is close to 100%, which highlights the importance of early detection, according to the doctor.

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Data from the National Cancer Institute’s SEER database show that metastatic prostate cancer has risen over the past decade, suggesting that “we have not improved early detection of the aggressive, curable disease that screening is meant to catch,” Vigneswaran said.

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“The goal of screening is to find the cancers that need treatment while they are still curable, without raising the number of men who screen positive but don’t have aggressive disease,” he said.

Stockholm3 could reduce the need for unnecessary MRIs and biopsies, according to the researcher.

The findings did have some limitations. Stockholm3 is an investigational device and is not available for sale in the U.S., Vigneswaran noted.

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The test estimates a man’s risk of aggressive prostate cancer, but a biopsy remains the gold standard for confirming the disease.

The company plans to seek FDA approval to use the test for routine screening and will “generate the evidence needed to support that pathway, including U.S. data,” Vigneswaran said.