Health

Humans’ Wounds Heal Much More Slowly Than Other Mammals’

Published

11 months ago

May 1, 2025

Humans’ Wounds Heal Much More Slowly Than Other Mammals’

Watching wild baboons in Kenya, Akiko Matsumoto-Oda, an evolutionary biologist and primatologist at the University of the Ryukyus in Japan, had a front-row seat to the violence between these monkeys, especially the males.

“I was struck by how frequently they sustained injuries,” she said, “and, even more, by how rapidly they recovered — even from seemingly severe wounds.”

Compared with her own experiences with nicks and cuts, the baboons’ ability to heal seemed like a superpower.

In a study published on Wednesday in Proceedings of the Royal Society B, Dr. Matsumoto-Oda and her colleagues compared the healing rates of humans, chimpanzees, monkeys and mice. They found that human wounds took more than twice as long to heal as wounds of any of the other mammals. Our slow healing may be a result of an evolutionary trade-off we made long ago, when we shed fur in favor of naked, sweaty skin that keeps us cool.

When possible, the researchers wanted to study healing in a way that was less violent and more controlled than watching wild baboons.

To measure human healing, they recruited 24 patients who were having skin tumors removed at the University of the Ryukyus Hospital. To gather data on chimpanzees, which are some of our closest animal relatives, researchers observed five captive chimps at the Kumamoto Sanctuary of the Kyoto University Wildlife Research Center, which houses animals formerly used in pharmaceutical research. The chimps’ wounds, like those of wild baboons, mostly came from tiffs between the animals.

The study’s other primate subjects, all kept at the Kenya Institute of Primate Research, included olive baboons, Sykes’ monkeys and vervet monkeys. Researchers anesthetized the monkeys, surgically wounded them and then monitored their recovery. “As a field researcher, I personally believe that invasive studies should be minimized as much as possible,” said Dr. Matsumoto-Oda, who noted that bite wounds on wild baboons are often similar in size to the surgical wounds in the study, but deeper.

Finally, to compare humans and primates with more distantly related mammals, researchers anesthetized and surgically wounded mice and rats.

Based on her field observations, Dr. Matsumoto-Oda was prepared to see humans healing more slowly than the other animals. The 24 people regrew skin at about a quarter of a millimeter per day, on average.

What surprised Dr. Matsumoto-Oda more was the consistency between the healing rates of the animal subjects, including chimpanzees. There was no significant difference in the speedy skin regrowth among different primates, which grew about 0.62 millimeters of new skin per day, or between primates and rodents. Humans were the clear outliers.

Elaine Fuchs, a stem cell biologist at the Rockefeller University who studies skin growth and repair and was not involved in the new research, said the results were what she would have expected. That’s because skin healing depends on hair.

Each hair grows from a hair follicle, which also houses stem cells. Normally, those stem cells just make more hair. But when called upon, they can grow new skin instead. “When the epidermis is wounded, as in most kinds of scratches and scrapes, it’s really the hair-follicle stem cells that do the repair,” Dr. Fuchs said.

Furry animals are covered in follicles, which help quickly close up wounds in mice or monkeys. By comparison, “human skin has very puny hair follicles,” Dr. Fuchs said. And our ancestors lost many of those follicles, packing their skin with sweat glands instead. Sweat glands also have stem cells, but they’re much less efficient at repairing wounds, Dr. Fuchs said.

Why did we make that trade during evolution, giving up so much of our hair and its protective properties? The glands that make the watery, salty sweat that dampens our shirts on a hot day are called eccrine glands. Most furry mammals have them only in certain places, mainly the soles of their paws. But human ancestors went all-in on sweat — modern humans have millions of sweat glands all over our bodies, and they’re about 10 times denser than those of chimpanzees.

“We evolved to cool by sweating profusely,” said Daniel Lieberman, an evolutionary biologist at Harvard University. Our abundant sweat glands and lack of fur let our ancestors engage in physical activity in hot environments, Dr. Lieberman said, and cooled the machinery of our big brains.

The benefits of trading hair for sweat must have outweighed the costs. Dr. Matsumoto-Oda and her co-authors speculate that social support among prehistoric humans might have helped wounded people stay alive, despite our slower healing. (Or maybe they had ways to treat wounds, like orangutans and chimps seem to.)

“The evolutionary disadvantage is that wound healing is slowed,” Dr. Fuchs said, but humans also gained evolutionary advantages by losing hair.

“They can put on a coat if they need to,” she added.

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Health

Giant golden spiders could spread this summer; experts downplay health risk

Published

9 hours ago

March 28, 2026

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Giant golden spiders could spread this summer; experts downplay health risk

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Large, palm-sized spiders are spinning massive golden webs across porches and power lines, and, according to experts, they’re here to stay.

The Joro spider, which has a leg span up to 4 inches and markings of neon yellow, blue-black and red, was first recorded in Georgia in 2013.

Since its arrival — likely as a hitchhiker on a shipping container or an airplane from Asia, experts say — the arachnid has been steadily marching north.

DOZENS SICKENED AS POTENTIALLY DEADLY FUNGUS SPREADS IN SOUTHERN STATE

The spiders have so far been spotted in Georgia, North Carolina, South Carolina and Tennessee.

They are expected to spread throughout eastern North America, at least as far north as Pennsylvania and possibly further in warmer, coastal areas, according to Penn State.

Joro spiders can “fly” by shooting out silk parachutes that carry them on the wind. (Stuart Cahill/Boston Herald)

To travel, the spider uses a technique called “ballooning,” in which hatchlings release fine silk threads that catch air currents and carry them over long distances.

Ian Williams, an entomologist with Orkin, said he counted 200 adult spiders by September of last year on his one-acre property near Atlanta.

POPULAR HONEYMOON DESTINATION FACES AVIAN MALARIA THREAT, SPREAD BY MOSQUITOES

“They’re quite intimidating looking spiders, and they make very large webs,” he told Fox News Digital. “The webbing itself, if it catches the sunlight, has a golden hue to it. And it’s very strong.”

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Despite the arachnid’s striking appearance, experts agree that people shouldn’t panic. Research shows the Joro is among the “shyest” spiders ever documented. When disturbed, they often sits motionless for over an hour rather than attacking.

Joro spiders like to spin their webs up high near houses, trees and even power lines, an expert said. (Stuart Cahill/Boston Herald)

“While they’re large spiders, they don’t have large fangs. And, so, it’s difficult for them to bite humans,” Williams noted.

Even in the rare event of a nip, the expert said the venom is weak, comparable to a localized bee sting, and carries “no medical importance.”

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As an invasive species, the Joro’s impact is still being weighed by scientists.

“One of the big concerns is that they potentially out-compete native species of spiders,” Williams said.

Physical removal is more efficient than pesticides, according to an expert. (iStock)

A prolific hunter, the Joro spider catches everything from mosquitoes to large, meaty insects like cicadas. It is unclear whether it steals food from native garden spiders.

To prevent Joro spiders from nesting on your porch or property, experts recommend using a broom or long pole to knock the web down.

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“Spiders may get the message, ‘Hey, I’m not going to keep remaking my same web in the same area,’” Williams said.

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Physical removal is more effective than pesticides, which often miss the spiders in their high, open-air webs.

For those who spot a Joro spider in a new area, experts suggest logging the sighting on apps like iNaturalist to help researchers track their northern migration.

Khloe Quill is a lifestyle production assistant with Fox News Digital. She and the lifestyle team cover a range of story topics including food and drink, travel, and health.

Health

Another state bans ‘gas station heroin’ as officials warn of deadly risks

Published

22 hours ago

March 27, 2026

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Another state bans ‘gas station heroin’ as officials warn of deadly risks

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Conversation-starters

→ March Madness sparks surprising surge in men’s sexual procedure

→ Cannabis benefits called into question in major study

→ ‘Call a Boomer’ payphones help cure loneliness across generations

Along a bustling sidewalk in Boston, a bright yellow payphone invites folks to “Call a Boomer.” (Matter Neuroscience)

Food for thought

→ Eating meat tied to lower dementia risk, study suggests

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→ Why your sugar cravings won’t go away, even after cutting sweets

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This article was written by Fox News staff.

Health

Dementia risk signals could lie in simple blood pressure readings, researchers say

Published

1 day ago

March 27, 2026

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Dementia risk signals could lie in simple blood pressure readings, researchers say

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Simple measurements taken during routine blood pressure checks could predict dementia risk years before symptoms appear.

That’s according to new research presented this week at the American College of Cardiology’s Annual Scientific Session in Louisiana.

The findings draw on two studies led by researchers at Georgetown University, which suggest that monitoring how blood vessels age and stiffen over time can provide a window into future cognitive health.

LURKING DEMENTIA RISK EXPOSED BY BREAKTHROUGH TEST 25 YEARS BEFORE SYMPTOMS

Data shows rates of dementia and aging-related cognitive decline are expected to increase as populations age, and half of U.S. adults have high blood pressure (hypertension).

Scientists believe that efforts to better address hypertension, a key contributor to heart disease and a risk factor for dementia, could affect both cardiac and brain health.

Data shows rates of dementia and aging-related cognitive decline are expected to increase as populations age. Meanwhile, half of U.S. adults have high blood pressure. (iStock)

“Blood pressure management isn’t just about preventing heart attacks and strokes; it may also be one of the most actionable strategies for preserving cognitive health,” Dr. Newton Nyirenda, the study’s lead author and an epidemiologist at Georgetown University in Washington, said in a press release.

The research focused on two metrics, the pulse pressure-heart rate index and estimated pulse wave velocity. Both were calculated using data collected during standard doctor visits, such as heart rate, age and blood pressure.

“Blood pressure management isn’t just about preventing heart attacks and strokes; it may also be one of the most actionable strategies for preserving cognitive health.”

Researchers examined five years of data patterns for more than 8,500 people in the SPRINT trial, a large study of adults 50 years and older with hypertension. In the follow-up, 323 of the participants developed probable dementia.

HIDDEN BRAIN CONDITION MAY QUADRUPLE DEMENTIA RISK IN OLDER ADULTS, STUDY SUGGESTS

In one study, the team found the pulse pressure-heart rate index was a strong independent predictor of dementia risk in adults over 50. For participants under 65, every one-unit increase was associated with a 76% higher risk of developing dementia.

For participants under 65, an increase in the pulse pressure-heart rate index was associated with a 76% higher risk of developing dementia. (iStock)

The second study found that adults with consistently elevated or rapidly increasing pulse wave velocity were more likely to develop dementia than those with stable velocity, even after accounting for factors like smoking, gender and cardiovascular history.

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“Our findings suggest that vascular aging patterns may provide meaningful insight into future dementia risk,” said Nyirenda. “This reinforces the idea that managing vascular health earlier in life may influence long-term brain health.”

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The team emphasized that clinicians should tailor risk assessments and treatment strategies to the individual.

Further studies are needed to confirm these parameters and determine whether changing vascular aging trajectories reduces dementia risk. (iStock)

“You don’t want to wait until a patient starts manifesting cognitive decline before you act,” said senior study author Sula Mazimba, an associate professor at the University of Virginia.

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Researchers noted the study could not establish causation. Other limitations included the fact that participants already had hypertension and elevated cardiovascular risk, meaning the findings may not apply to people without those conditions.

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Further studies are needed to confirm these findings and to determine whether improving blood vessel health over time could reduce dementia risk.

Khloe Quill is a lifestyle production assistant with Fox News Digital. She and the lifestyle team cover a range of story topics including food and drink, travel, and health.