Aging is often depicted as a steady decline, but new research suggests that many older adults actually improve over time.

Using more than a decade of data from a large, representative study of older Americans, Yale University researchers found that nearly half of adults 65 and older showed improvement in cognitive function, physical function or both.

The improvements were consistent across the study population, and were linked to the participants’ mindset about aging, according to a press release.

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“In contrast to a predominant belief or stereotype that age is a time of continuous and inevitable decline, we found evidence that a meaningful number of older persons actually show improvement over 12 years in cognitive and/or physical health,” lead author Becca Levy, a professor of social and behavioral sciences at Yale, told Fox News Digital.

The research, which was published in the journal Geriatrics, relied on data from the Health and Retirement Study, a federally supported, long-running survey of older Americans.

Researchers tracked changes in cognition using global performance tests and measured physical function based on walking speed, which was seen as a “vital sign” because of its strong links to disability, hospitalization and mortality.

Over a 12-year period, 45% of participants improved either mentally or physically. About 32% showed cognitive gains, while 28% improved physically, according to the study.

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“If you average everyone together, you see decline,” Levy said. “But when you look at individual trajectories, you uncover a very different story. A meaningful percentage of the older participants … got better.”

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A participant’s beliefs about aging appeared to influence the results, as those with more positive age beliefs were significantly more likely to show improvements in both cognition and walking speed.

This remained true even after accounting for factors such as age, sex, education, chronic disease, depression and the length of follow-up. Improvements were seen even among participants who started with “normal” levels of function, not just those recovering from injuries or illness. 

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“Individuals who have taken in more positive age beliefs … tend to have a lower stress response and lower stress biomarkers,” Levy said. Because age beliefs are modifiable, she noted, there could be a capacity for improvements later in life.

The study did have some limitations, the researchers acknowledged. It didn’t look at how muscles or brain cells change and adapt, which could help explain why people improved.

Future studies should examine improvement patterns for other types of cognition, such as spatial memory, they added.

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“In addition, although our participants were drawn from a nationally representative sample, it would be useful to examine patterns of improvement in additional cohorts that have a greater representation of different ethnic minority groups,” the researchers noted in the study.

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The authors said they hope the findings will debunk the myth that continuous physical and cognitive decline is inevitable.

“We found evidence that there could be psychological pathways, behavioral pathways and physiological pathways [by which age beliefs impact health],” said Levy. “It’s common, and it should be included in our understanding of the aging process.”

Scientists and physicians agree that there’s been a general decline in male fertility — but they aren’t sure why.

Social media buzz has pointed to a few environmental exposures as potential factors, including cellphones and electric vehicles.

But the reality is “more complicated” than that, according to experts who recently spoke to National Geographic.

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Although it’s not clear whether the decline is at a stage where it should be considered a crisis, numbers show that overall fertility — demographically measured by the number of babies born compared to women of child-bearing age — has decreased.

Dr. Alex Robles of the Columbia University Fertility Center in New York confirmed that clinical practitioners are “certainly seeing more couples where the male factor contributes to infertility.”

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“At least one-third of couples we evaluate have some male component,” he told Fox News Digital.

A 2017 meta-analysis published in Oxford Journals: Human Reproduction Update found that sperm counts in Western countries have declined by almost 60% globally since 1973. The 2023 update confirmed these same results.

Lead study author and epidemiologist Hagai Levine warned that this trend could lead to human extinction if it isn’t addressed.

“This is the canary in the coal mine,” Levine, public health physician at the Hebrew University-Hadassah Braun School of Public Health, told National Geographic. “It signifies that something is very wrong with our current environment, as lower sperm counts predict morbidity and mortality.”   

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These findings have been contradicted by other studies, however. A 2025 Cleveland Clinic analysis of studies from the last 53 years found sperm counts to be steady.

“There is no evidence to suggest that this decline is the cause of a precipitous decline in the ability to cause pregnancies,” primary study author Scott Lundy, a reproductive urologist at Cleveland Clinic, told National Geographic. “Most men, even with a modest decline in sperm counts, will still have no issues conceiving.”

Potential factors of decline

Multiple lifestyle factors can lead to a decline in male fertility, Robles noted, including obesity, smoking and diet, as well as environmental exposures and delayed parenthood.

National Geographic also reported that heavy drinking and marijuana use directly contribute to declining fertility and that quitting these habits, while also exercising and losing weight, can help.

Systemic inflammation, infection and disease can also have a “big, profound effect on the current status of fertility,” Lundy told National Geographic. 

Those who are getting over a fever from an infection, like the flu or COVID, will have a “drastically lower” sperm count for three months, he said.

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Male infertility can also be a marker of overall health, according to Robles. “Poor semen parameters are associated with other medical conditions and may signal underlying metabolic, hormonal or environmental issues,” he told Fox News Digital.

Allan Pacey, deputy dean of the Faculty of Biology, Medicine and Health at the University of Manchester, told National Geographic that the decline could be caused by increased use of contraception, as well as men waiting longer to have children or choosing not to have them at all.

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Microplastics have also been raised on social media as a potential culprit, but the effects are unclear, according to experts.

There is some evidence of endocrine-disrupting chemicals — which are substances found in reusable plastics and some disposable products — altering male fertility, Lundy revealed to National Geographic.

Myths busted

Concerns have circulated on social media that keeping a cellphone in a front pocket could harm male fertility. While Lundy said such an effect is biologically possible, there is currently no scientific evidence supporting the claim.

Another common myth is that infertility is mostly a women’s issue, Robles noted, but male factors contribute to about one-third to one-half of all cases.

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The claim that taking supplements can boost sperm counts is another common myth, he said, adding that it’s not backed by strong scientific evidence.

“Men should focus on factors that we know matter: maintaining a healthy weight, avoiding tobacco, limiting alcohol and managing chronic health conditions,” Robles advised. 

Experts recommend seeing a urologist to address fertility concerns. Robles said his approach begins with an evaluation, semen analysis, hormonal testing and medical history, while also exploring lifestyle factors.

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In addition to traditional treatment options, Robles said his fertility center also uses advanced tools that incorporate AI and robotics.

“Technologies like this are expanding options for patients who previously had very limited paths to biological parenthood,” he said.

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