6 reasons dogs truly are man’s best friend

Research suggests dog ownership may improve heart health, decrease depression, and even help you live longer.

6 reasons dogs truly are man’s best friend
  • Dogs have been man's best friend for at least the past 15,000 years.
  • Science now shows that this symbiotic relationship has been as beneficial for humans as their canine companions.
  • Benefits of dog ownership include familial ties, a reduce risk of schizophrenia, and improved cardiovascular health.


Under cover of darkness, a pack of ancient wolves slowly stalk the camps of our nomadic ancestors. But they are not on the prowl. These timid, congenial Canidaes have discovered they can scavenge human kills and midden piles for more reward, and far less risk, than the hunt.

Over successive generations, their offspring grow more docile and more dependent on their human benefactors. In time humans adopt these four-legged moochers, taking them into their service with the tacit agreement of better food and companionship. And so, the human-dog relationship was born.

That's one possibility at least. All that's generally agreed upon is that dogs became man's best friend as early as 15,000 years ago — though some fossil evidence suggests domestication as far back as 30,000 years. As science writer James Gorman points out, this means we loved our tail-wagging besties before inventing agriculture, language, or permanent homes and even before we domesticated cows, goats, and, of course, cats.

"As we became friends with them, they became friends with us, and we have a dependency that's charming," Bill Nye, science guy and lover of all good dogs, told us in a 2015 interview. "It's enriched both the dog lives and the human lives."

For humans, the perks of the dog-human relationship run much deeper than games of fetch or a handy excuse to go for a nice, long walk.

Dogs see us as family

Dogs see their people as family, and the feeling seems to be mutual.

(Photo: PxHere)

It's not our imaginations or a poetic attempt to explain behavior through personification. Dogs do view their people as family.

Cognition scientists at Emory University placed dogs in an MRI machine and scanned their brains while presenting them with different odors. Some aromas were of food. Others were from other dogs. And some were from the dogs' human companions. The dogs' brains' reward centers lit up most when presented with the human scents, showing they prioritized human relationships.

These results bolstered other research that shows dogs act similarly to human sounds and that they are the only non-primates to run toward humans for protection and comfort.

Dogs reduce the risk of schizophrenia

A little girl meets Lothair and Molly, two certified therapy dogs, at U.S. Air Force Base Hospital Langley.

(Photo: Brittany Paerschke-O'Brain/U.S. Air Force)

Dogs may be able to curb the risk of some mental diseases. That's the conclusion of research published in the peer-reviewed journal PLoS ONE, which found a link between dog ownership and a reduced risk of schizophrenia.

The researchers looked at 1,371 men and women across the socioeconomic spectrum. Roughly 400 participants suffered from schizophrenia, another 400 from bipolar disorder, and about 600 were controls. After a survey in which the participants were asked about pets, the researchers compared ownership with rates of mental illness.

They discovered that dog ownership before the age of 13 correlated with a 25 percent reduced risk of schizophrenia. Participants who owned dogs in the first years of life showed the largest protective effect.

"There are several plausible explanations for this possible 'protective' effect from contact with dogs," lead author Robert Yolken said in a statement. "Perhaps something in the canine microbiome that gets passed to humans and bolsters the immune system against or subdues a genetic predisposition to schizophrenia."

Sorry, ailurophiles. Cats did not show a similar link between ownership and a reduced risk of mental diseases.

Dogs are your heart's best friend, too

Regular walks with your dog is great exercise and boosts cardiovascular health.

(Photo: PxHere)

The health benefits aren't just in the mind. Preliminary research published in Mayo Clinic Proceedings: Innovations, Quality & Outcomes suggests that pet ownership boosts heart health, especially if that pet is a dog.

Researchers evaluated roughly 1,800 participants using the American Heart Association's Life's Simple 7, seven life factors that people can improve to help achieve cardiovascular well-being. They then compared the health of pet owners with those who did not own pets and found a correlation between dog ownership and heart health. The researchers associated this salubrious effect with increased engagement and physical activity.

"In general, people who owned any pet were more likely to report more physical activity, better diet and blood sugar at an ideal level," Andrea Maugeri, a researcher with the International Clinical Research Center at St. Anne's University Hospital in Brno, said in a statement. "The greatest benefits from having a pet were for those who owned a dog, independent of their age, sex and education level."

Follow-up evaluations are scheduled until 2030.

Dogs make life better (and longer)

An older gentleman sits with his canine companion.

(Photo: Pxfuel)

Better heart health means a better chance to live longer. That's according to a recent study and meta-analysis published in Circulation: Cardiovascular Quality and Outcomes.

The research found that dog owners who survived a heart attack were at a 33 percent reduced risk of early death compared to non-dog survivors. The same held true for stroke survivors (27 percent). Better still, dog ownership correlated with a 24 percent reduced risk of all-cause mortality, likely explained by an increase in physical activity and a decrease in depression and loneliness.

A study published in Scientific Reports corroborates a canine's life-giving, heart-healthy impact. The researchers reviewed the national registries for more than 3.4 million Swedes with no cardiovascular disease before 2001. Looking at the association between dog ownership and cardiovascular health, they found that single dog owners had a lowered risk of death, either due to cardiovascular disease (11 percent) or other causes (33 percent).

In a statement, lead junior author Mwenya Mubanga noted, "A very interesting finding in our study was that dog ownership was especially prominent as a protective factor in persons living alone, which is a group reported previously to be at higher risk of cardiovascular disease and death than those living in a multi-person household. Perhaps a dog may stand in as an important family member in the single households."

Dogs teach us ways to learn

Put simply, dogs are better at ignoring bad advice than their human peers. Research out of Yale University's Canine Cognition Center tasked dogs with retrieving treats from a puzzle. The researchers presented the steps to solve the puzzle but included many extraneous steps in the demonstration. When it was the dogs' turn, they nimbly skipped the unnecessary steps, thereby showing their ability to filter information effectively.

How did human children perform? Not so great. The children settled on pure imitation, regardless of whether a step proved useful in solving the puzzle.

"This tells us something really important about how humans learn relative to other animals," Big Think author Arpan Bhattacharyya wrote on the study. "We're really trusting of the information that we get from other individuals – even more trusting than dogs are.

"And what this means is we have to be really careful about the kinds of information we present ourselves with. We're not going to have the right filter for bad information, so we should stick to looking at information that's going to be positive, information that's going to be good."

Dogs teach us about ourselves

Dogs really do resemble their owners.

(Photo: PxHere)

Dogs resemble their owners in more ways than floppy jowls or a perky gait. Dogs mirror their owners' personalities, and owners can use this information to better understand themselves.

Research published in the Journal of Research in Personality surveyed more than 1,600 dog owners, representing about 50 different breeds. They found that dog owners shaped their dogs' personalities. Extroverted owners rated their dogs as more active and playful, while the owners of more fearful dogs tended to exhibit more negative emotions. Similarly, more agreeable owners were guardians of less aggressive pets.

"We expected the dogs' personalities to be fairly stable because they don't have wild lifestyle changes humans do, but they actually change a lot. We uncovered similarities to their owners, the optimal time for training and even a time in their lives that they can get more aggressive toward other animals," lead author William Chopik said in a release.

Another study in Scientific Reports showed similar findings regarding stress. The researchers took hair and fur samples from owners and their dogs to measure both for the stress hormone cortisol. They found a correlation in long-term stress between the two.

More than simply good dogs

These are six ways that science has discovered dogs aid their interspecies partner. As genetic research advances, dogs may prove they are man's best friends in unforeseen ways. Scientists studying the canine genome have found a number of canine disorders that closely resemble those found in humans, including some cancers. Further study may provide a wealth of information that could help us solve our own genetic mysteries.

A new study says it's okay to eat red meat. An immediate uproar follows.

Even before publication, health agencies were asking the journal not to publish the research.

Photo by Isa Terli/Anadolu Agency/Getty Images

Surprising Science
  • A new study in the Annals of Internal Medicine found little correlation between red meat consumption and health problems.
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  • Beef and dairy production is one of the leading drivers of climate change, forcing humans to weigh personal health against the environment.
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COVID and "gain of function" research: should we create monsters to prevent them?

Gain-of-function mutation research may help predict the next pandemic — or, critics argue, cause one.

Credit: Guillermo Legaria via Getty Images
Coronavirus

This article was originally published on our sister site, Freethink.

"I was intrigued," says Ron Fouchier, in his rich, Dutch-accented English, "in how little things could kill large animals and humans."

It's late evening in Rotterdam as darkness slowly drapes our Skype conversation.

This fascination led the silver-haired virologist to venture into controversial gain-of-function mutation research — work by scientists that adds abilities to pathogens, including experiments that focus on SARS and MERS, the coronavirus cousins of the COVID-19 agent.

If we are to avoid another influenza pandemic, we will need to understand the kinds of flu viruses that could cause it. Gain-of-function mutation research can help us with that, says Fouchier, by telling us what kind of mutations might allow a virus to jump across species or evolve into more virulent strains. It could help us prepare and, in doing so, save lives.

Many of his scientific peers, however, disagree; they say his experiments are not worth the risks they pose to society.

A virus and a firestorm

The Dutch virologist, based at Erasmus Medical Center in Rotterdam, caused a firestorm of controversy about a decade ago, when he and Yoshihiro Kawaoka at the University of Wisconsin-Madison announced that they had successfully mutated H5N1, a strain of bird flu, to pass through the air between ferrets, in two separate experiments. Ferrets are considered the best flu models because their respiratory systems react to the flu much like humans.

The mutations that gave the virus its ability to be airborne transmissible are gain-of-function (GOF) mutations. GOF research is when scientists purposefully cause mutations that give viruses new abilities in an attempt to better understand the pathogen. In Fouchier's experiments, they wanted to see if it could be made airborne transmissible so that they could catch potentially dangerous strains early and develop new treatments and vaccines ahead of time.

The problem is: their mutated H5N1 could also cause a pandemic if it ever left the lab. In Science magazine, Fouchier himself called it "probably one of the most dangerous viruses you can make."

Just three special traits

Recreated 1918 influenza virionsCredit: Cynthia Goldsmith / CDC / Dr. Terrence Tumpey / Public domain via Wikipedia

For H5N1, Fouchier identified five mutations that could cause three special traits needed to trigger an avian flu to become airborne in mammals. Those traits are (1) the ability to attach to cells of the throat and nose, (2) the ability to survive the colder temperatures found in those places, and (3) the ability to survive in adverse environments.

A minimum of three mutations may be all that's needed for a virus in the wild to make the leap through the air in mammals. If it does, it could spread. Fast.

Fouchier calculates the odds of this happening to be fairly low, for any given virus. Each mutation has the potential to cripple the virus on its own. They need to be perfectly aligned for the flu to jump. But these mutations can — and do — happen.

"In 2013, a new virus popped up in China," says Fouchier. "H7N9."

H7N9 is another kind of avian flu, like H5N1. The CDC considers it the most likely flu strain to cause a pandemic. In the human outbreaks that occurred between 2013 and 2015, it killed a staggering 39% of known cases; if H7N9 were to have all five of the gain-of-function mutations Fouchier had identified in his work with H5N1, it could make COVID-19 look like a kitten in comparison.

H7N9 had three of those mutations in 2013.

Gain-of-function mutation: creating our fears to (possibly) prevent them

Flu viruses are basically eight pieces of RNA wrapped up in a ball. To create the gain-of-function mutations, the research used a DNA template for each piece, called a plasmid. Making a single mutation in the plasmid is easy, Fouchier says, and it's commonly done in genetics labs.

If you insert all eight plasmids into a mammalian cell, they hijack the cell's machinery to create flu virus RNA.

"Now you can start to assemble a new virus particle in that cell," Fouchier says.

One infected cell is enough to grow many new virus particles — from one to a thousand to a million; viruses are replication machines. And because they mutate so readily during their replication, the new viruses have to be checked to make sure it only has the mutations the lab caused.

The virus then goes into the ferrets, passing through them to generate new viruses until, on the 10th generation, it infected ferrets through the air. By analyzing the virus's genes in each generation, they can figure out what exact five mutations lead to H5N1 bird flu being airborne between ferrets.

And, potentially, people.

"This work should never have been done"

The potential for the modified H5N1 strain to cause a human pandemic if it ever slipped out of containment has sparked sharp criticism and no shortage of controversy. Rutgers molecular biologist Richard Ebright summed up the far end of the opposition when he told Science that the research "should never have been done."

"When I first heard about the experiments that make highly pathogenic avian influenza transmissible," says Philip Dormitzer, vice president and chief scientific officer of viral vaccines at Pfizer, "I was interested in the science but concerned about the risks of both the viruses themselves and of the consequences of the reaction to the experiments."

In 2014, in response to researchers' fears and some lab incidents, the federal government imposed a moratorium on all GOF research, freezing the work.

Some scientists believe gain-of-function mutation experiments could be extremely valuable in understanding the potential risks we face from wild influenza strains, but only if they are done right. Dormitzer says that a careful and thoughtful examination of the issue could lead to processes that make gain-of-function mutation research with viruses safer.

But in the meantime, the moratorium stifled some research into influenzas — and coronaviruses.

The National Academy of Science whipped up some new guidelines, and in December of 2017, the call went out: GOF studies could apply to be funded again. A panel formed by Health and Human Services (HHS) would review applications and make the decision of which studies to fund.

As of right now, only Kawaoka and Fouchier's studies have been approved, getting the green light last winter. They are resuming where they left off.

Pandora's locks: how to contain gain-of-function flu

Here's the thing: the work is indeed potentially dangerous. But there are layers upon layers of safety measures at both Fouchier's and Kawaoka's labs.

"You really need to think about it like an onion," says Rebecca Moritz of the University of Wisconsin-Madison. Moritz is the select agent responsible for Kawaoka's lab. Her job is to ensure that all safety standards are met and that protocols are created and drilled; basically, she's there to prevent viruses from escaping. And this virus has some extra-special considerations.

The specific H5N1 strain Kawaoka's lab uses is on a list called the Federal Select Agent Program. Pathogens on this list need to meet special safety considerations. The GOF experiments have even more stringent guidelines because the research is deemed "dual-use research of concern."

There was debate over whether Fouchier and Kawaoka's work should even be published.

"Dual-use research of concern is legitimate research that could potentially be used for nefarious purposes," Moritz says. At one time, there was debate over whether Fouchier and Kawaoka's work should even be published.

While the insights they found would help scientists, they could also be used to create bioweapons. The papers had to pass through a review by the U.S. National Science Board for Biosecurity, but they were eventually published.

Intentional biowarfare and terrorism aside, the gain-of-function mutation flu must be contained even from accidents. At Wisconsin, that begins with the building itself. The labs are specially designed to be able to contain pathogens (BSL-3 agricultural, for you Inside Baseball types).

They are essentially an airtight cement bunker, negatively pressurized so that air will only flow into the lab in case of any breach — keeping the viruses pushed in. And all air in and out of the lap passes through multiple HEPA filters.

Inside the lab, researchers wear special protective equipment, including respirators. Anyone coming or going into the lab must go through an intricate dance involving stripping and putting on various articles of clothing and passing through showers and decontamination.

And the most dangerous parts of the experiment are performed inside primary containment. For example, a biocontainment cabinet, which acts like an extra high-security box, inside the already highly-secure lab (kind of like the radiation glove box Homer Simpson is working in during the opening credits).

"Many people behind the institution are working to make sure this research can be done safely and securely." — REBECCA MORITZ

The Federal Select Agent program can come and inspect you at any time with no warning, Moritz says. At the bare minimum, the whole thing gets shaken down every three years.

There are numerous potential dangers — a vial of virus gets dropped; a needle prick; a ferret bite — but Moritz is confident that the safety measures and guidelines will prevent any catastrophe.

"The institution and many people behind the institution are working to make sure this research can be done safely and securely," Moritz says.

No human harm has come of the work yet, but the potential for it is real.

"Nature will continue to do this"

They were dead on the beaches.

In the spring of 2014, another type of bird flu, H10N7, swept through the harbor seal population of northern Europe. Starting in Sweden, the virus moved south and west, across Denmark, Germany, and the Netherlands. It is estimated that 10% of the entire seal population was killed.

The virus's evolution could be tracked through time and space, Fouchier says, as it progressed down the coast. Natural selection pushed through gain-of-function mutations in the seals, similarly to how H5N1 evolved to better jump between ferrets in his lab — his lab which, at the time, was shuttered.

"We did our work in the lab," Fouchier says, with a high level of safety and security. "But the same thing was happening on the beach here in the Netherlands. And so you can tell me to stop doing this research, but nature will continue to do this day in, day out."

Critics argue that the knowledge gained from the experiments is either non-existent or not worth the risk; Fouchier argues that GOF experiments are the only way to learn crucial information on what makes a flu virus a pandemic candidate.

"If these three traits could be caused by hundreds of combinations of five mutations, then that increases the risk of these things happening in nature immensely," Fouchier says.

"With something as crucial as flu, we need to investigate everything that we can," Fouchier says, hoping to find "a new Achilles' heel of the flu that we can use to stop the impact of it."

The misguided history of female anatomy

From "mutilated males" to "wandering wombs," dodgy science affects how we view the female body still today.

Credit: Hà Nguyễn via Unsplash
Sex & Relationships
  • The history of medicine and biology often has been embarrassingly wrong when it comes to female anatomy and was surprisingly resistant to progress.
  • Aristotle and the ancient Greeks are much to blame for the mistaken notion of women as cold, passive, and little more than a "mutilated man."
  • Thanks to this dubious science, and the likes of Sigmund Freud, we live today with a legacy that judges women according to antiquated biology and psychology.
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