The Truth About Cats: They're Good for Us

Discovery News

Health

The Truth About Cats: They're Good for Us

Aug 21, 2012 03:00 AM ET


by Jennifer Viegas 

THE GIST

- Cats have gotten a bad health rap, as new research suggests they may be beneficial to human health.

- Cats could even help to lower human risk of cancer.

- Cats may harbor T. gondii, but feline ownership does not predict risk of infection with this parasite.

News headlines over the past few years have linked cat ownership to everything from cancer to craziness, but new studies suggest that cats are actually beneficial to human health, and may even reduce our risk for cancer and other diseases.

Reports in this week's issue of Biology Letters, for example, counter the tabloid-suggested link between cats and human brain cancer.
Marion Vittecoq of the Tour du Valat research center and her colleagues conclude that cats should not be blamed for human cancer. In fact, studies show just the opposite.

Vittecoq told Discovery News that "according to our knowledge, studies that have focused on the link between cancer and cat ownership so far have found either no association at all or a reduced risk of cancer in cat owners."

NEWS: Cats Adore, Manipulate Women

As an example, she and co-author Frédéric Thomas cite a National Institutes of Health Study by G.J. Tranah and colleagues. It found dog and cat owners have a reduced risk of non-Hodgkin's lymphoma. The longer the duration of pet ownership was, the less chance the individual would suffer from this type of cancer.

Why cats and dogs may benefit human health remains a mystery, but another study from earlier this month provides some intriguing clues. It found that infants having pets at home suffered from fewer respiratory tract illnesses.
"Our findings support the theory that during the first year of life, animal contacts are important, possibly leading to better resistance to infectious respiratory illnesses during childhood," wrote Eija Bergroth and colleagues in the paper, published in the journal Pediatrics.

Countless other studies demonstrate the mental health benefits of pet ownership, particularly for students, seniors and people with chronic illnesses. In such cases, pets can provide much needed comfort and companionship.

Cats have gotten a bad rap over the years, however, for a few different reasons. One is based on old ridiculous superstitions, such as how black cats are bad luck. The other, however, centers on a scientific debate concerning cancer and the protozoan parasite Toxoplasma gondii.

In earlier research, Vittecoq and Thomas determined that there is a positive correlation between this parasite and incidence of brain cancer. Cats can host this bug, and therein lies the "felines are bad for you" media frenzy over the past several months.

But the authors themselves indicate that cats have been mistakenly maligned, due to the other studies supporting the health benefits of cats, the fact that the connection between the parasite and cancer has still not been firmly established.

NEWS: Dogs and Cats Help Prevent Infections in Kids

Thomas explained that "humans usually get infected through the consumption of undercooked meat, especially sheep, containing asexual stages of T. gondii" or through contact with contaminated soil (which good hygiene remedies). Other studies show that ingestion of the bug in contaminated water, fruit, vegetables, and raw goat milk can lead to infection. The parasite is therefore somewhat similar to E. coli, in terms of transmission routes.

Victoria Benson of Oxford University's Cancer Epidemiology Unit, and her team also have a statement in the latest Biology Letters addressing this matter.
Benson and her team are conducting what's called the "Million Women Study," which investigates a tremendous amount of data concerning middle-aged women from the U.K. The scientists found zero association with incidence of brain cancer and women living with a cat.

"This, however, does not rule out the possibility that T. gondii infection from another source may be associated with brain cancer incidence," Benson and her team write.

If that other source, which may even be another parasite, is found, Thomas says it could "provide a means to reduce the risk of brain cancer, particularly in countries like France where the incidence of brain cancer and T. gondii are both high."
 

Forever And A Day: Can Our Bond With Dogs Survive Death?

 

Forever And A Day: Can Our Bond With Dogs Survive Death?

By Julie Hecht | October 17, 2014 |  

The views expressed are those of the author and are not necessarily those of Scientific American.

---

Grover Krantz was onto something when he had his remains donated to science. 

A professor of anthropology, he didn’t see why death should interrupt his life-long teaching. His body first went to the University of Tennessee’s Forensic Anthropology Center, where he contributed to the study of human decay. His skeleton was then moved to Smithsonian’s Museum of Natural History, where he can be found to this day. Back when Krantz first approached the Museum about housing his remains, he was upfront about the catch: his bones were to stay with those of his late Irish Wolfhounds, Clyde, Icky and Yahoo.

Krantz and his beloved companions didn’t stay behind the scenes for long. In 2009, he and Clyde, his first and favorite dog, were put on display in the exhibition Written in Bone: Forensic Files of the 17th-Century Chesapeake. The position of the two skeletons, together in life and death, captures the mutual adoration between the two species. In fact, the skeletons were posed using a picture of Krantz and Clyde from the good old days.

Maybe you find Krantz’ final directives on the extreme side. A Washington Post piece profiling Krantz’s life (and afterlife) suggests he had always been known for eccentricities. Even so, life-and-death ties with pets run deep.

A recent study published in Anthrozoös offers a novel approach to investigating what companion animals mean to us. For the study, lead researcher Cindy Wilson and her collaborators decided to analyze a unique datasource: the obituaries. Over the course of three months, they conducted a “bi-national, exploratory, content analysis of companion animals mentioned in newspaper obituaries.” They wanted to know: when people pass, do their obituaries make mention of a pet or pet survivor, and are donations requested to a pet-related charity?

A scan of 11,818 obituaries in The Washington Post (Washington, DC), The Richmond Times Dispatch (Virginia) and The Zurich (Switzerland) revealed that 2.2%, or 260 obituaries, met their criteria. Only one obituary in Switzerland mentioned an animal (in this case, a man’s surviving cat), and all others came from the States. Obituaries were roughly split between mentioning a pet survivor and requesting pet-related donations. Most non-human survivors mentioned were dogs, and the obituaries often gave the dogs’ names.

This study makes me think that many people might understand where Grover Krantz was coming from when he decided to spend eternity with his dogs. For one thing, the obituaries rarely used the word ‘pet.’ As the researchers explain, “these animals have most likely been elevated to family status…. To be listed in an obituary which is typically reserved for conventional kin extends the concept of fictive kin to these animals that appear in the last tribute to their human companions.” Fictive kin refers to non-blood relatives on equal footing with biological relatives. It seems companion animals can also serve as fictive kin.
In the obituaries, non-human animals were often listed as survivors alongside human family members. An octogenarian is described “as being survived by two nieces…a nephew…and a loyal canine companion, Shirley.” Another describes a man as leaving behind “his beloved granddogs, Brie Sherwin and Otis Huddleston. His non-furry grandchild will arrive in May.” The obituaries also contain the other side of the coin—the animals’ perceived response to the loss of a significant person. For example, “He will be sorely missed by Molly, his ever-present cocker spaniel companion.”

A study like this gives you pause. I imagine most researchers and practitioners in my field would agree: on one hand, we try to objectively study the inner world and workings of Canis familiaris (whether in their own right or as they compare to other species), but we also have personal relations with members of this species. There are some dogs who think I am the bees’ knees, and I feel the same.

When I was a kid, I used to have a reoccurring, one-sided conversation with my dog, Brandy. It usually took place at night when she was stretched out under the covers, somehow taking up three-fourths of the bed with her chihuahua-dachshund body. Before falling asleep, I’d lay out the rules, “If you ever die, I’ll kill you.” At the time, it seemed natural to couple such deep love with a threat. Like most dogs, she didn’t listen.

——

Picture: Krantz and Clyde via Smithsonian.com

Reference
Wilson C.C., Dennis C. Turner & Cara H. Olsen (2013). Companion Animals in Obituaries: An Exploratory Study, Anthrozoos: A Multidisciplinary Journal of The Interactions of People , 26 (2) 227-236. DOI: http://dx.doi.org/10.2752/175303713×13636846944204

About the Author: Julie Hecht is a canine behavioral researcher and science writer in New York City. She would really like to meet your dog. Follow on Twitter @DogSpies.

More »

The views expressed are those of the author and are not necessarily those of Scientific American.

Science proves that you love your dog like a baby

SALON

Science proves that you love your dog like a baby

We're going to go ahead and assume that the results apply to cats too...

Joanna Rothkopf




(Credit: Sinseeho via Shutterstock)

 
A PLOS ONE study recently confirmed what many of us already knew: dog love can be extremely similar to maternal love.

“Alloparenting,” or adopting and caring for different species– has occurred for tens of thousands of years (the first domesticated dog dates back to 32,000 years ago). Around two-thirds of American households have pets and spend over $50 billion every year on their well-being.

In this study, researchers from Massachusetts General Hospital sought to directly compare the “functional neuroanatomy of the human-pet bond with that of the maternal-child bond.” To do so, they had women look at photos of their babies and their dogs, as well as babies and dogs that they didn’t know.
“There was a common network of brain regions involved in emotion, reward, affiliation, visual processing and social cognition when mothers viewed images of both their child and dog,” reads the study. The unfamiliar photos didn’t provoke the same reaction.

The Washington Post’s Rachel Feltman reports:

But brain response to children and dogs wasn’t entirely the same: An area of the brain vital to processing faces was activated more by a dog picture than a child’s face, while parts of the midbrain were more active in response to children. It may be that facial cues are more important in human-to-dog communication, given our lack of common language. And the midbrain areas could be vital in forming human-to-human pair b0nds, National Geographic reports.

Although more research needs to be done to replicate the findings, it does make sense that we should have such important bonds with our pets.

“Pets hold a special place in many people’s hearts and lives, and there is compelling evidence from clinical and laboratory studies that interacting with pets can be beneficial to the physical, social and emotional wellbeing of humans,” said Lori Palley, DVM, of the MGH Center for Comparative Medicine and co-lead author of the report. “Several previous studies have found that levels of neurohormones like oxytocin – which is involved in pair-bonding and maternal attachment – rise after interaction with pets, and new brain imaging technologies are helping us begin to understand the neurobiological basis of the relationship, which is exciting.”

Joanna Rothkopf is an assistant editor at Salon, focusing on sustainability. Follow @JoannaRothkopf or email jrothkopf@salon.com.