Cats have lived with humans for thousands of years. And long before cat memes and viral TikToks took over the internet, they've been comforting us with their purrs and making us laugh with their weird antics.
But what does the research say – are cats good for us?
Living with a cat can have a profound – and sometimes surprising – effect on our physical and mental health. Still, living with cats is not without risks.
Part of the family
You may have heard cats don't have owners, they have "staff". In fact, multiple studies show the humans who live with them feel more like beloved relatives.
In a study of 1,800 Dutch cat owners, half said their cat was family. One in three viewed their cat as a child or best friend and found them loyal, supportive and empathetic.
Another US study developed a "family bondedness" scale and found cats were just as important a part of families as dogs.
Many cats would choose human interaction over food or toys. And they can distinguish when we are talking to them (rather than another human).
In fact we've adapted to each other. Cats are more likely to approach human strangers who first give a "kitty kiss" – narrowing your eyes and blinking slowly. And research suggests cats have developed specific meows that tune into our nurturing instincts.
What does this close relationship mean for health outcomes?
A sense of purpose
Owning a pet is associated with less social isolation. And some cat owners say "providing for the cat" increases their feelings of enjoyment and sense of purpose.
But the benefits of the relationship may depend on how you relate to your cat.
One study looked at different relationship styles between humans and cats, including "remote", "casual" and "co-dependent". It found people whose relationship with their cat was co-dependent or like a friend had a higher emotional connection to their pet.
Links to heart health
People who own – or have owned – a cat have a lower risk of dying from cardiovascular diseases such as stroke or heart disease. This result has been repeated in several studies.
However a problem interpreting population studies is they only tell us about an association. This means while people with cats have lower risk of dying from cardiovascular diseases, we can't say for sure cats are the cause.
Cat ownership has also been associated with some positive changes in the gut microbiota, especially in women, such as improved blood glucose control and reduced inflammation.
Helping mental health
Having cat or dog is also associated with higher psychological well-being. For people with depression, patting or playing with their cat has been shown to reduce symptoms (although this was over a short, two-hour period and can't be extrapolated longer-term).
Another way to find out about the health impact of cats is qualitative research: asking people what their cats mean to them, beyond the numbers.
When colleagues and I surveyed veterans, we found people more attached to their pets actually had poorer mental health scores. But their survey responses told a different story. One respondent said, "my cats are the reason I get up in the morning".
Another wrote:
I consider my pet to be a service animal. My cat helps me to relax when I'm dealing with my anxiety, depression or when I wake during the night from the frequent nightmares I have. My cat isn't just a pet to me, my cat is a part of me, my cat is part of my family.
It may be that veterans were more attached to their cats because they had worse mental health – and relied on their cats more for comfort – rather than the other way around.
Mental health downsides
It is possible being attached to your cat has downsides. If your cat becomes sick, the burden of caring for them may have a negative impact on your mental health.
In our study of owners whose cats had epilepsy, around one third experienced a clinical level of burden as caregivers that was likely to interfere with their day-to-day functioning.
Toxoplasmosis
Cats can also carry zoonotic diseases, which are infections which spread from animals to humans.
They are the main host for toxoplasmosis, a parasite excreted in cat faeces which can affect other mammals, including humans. The parasite is more likely to be carried by feral cats that hunt for their food than domestic cats.
Most people have mild symptoms that may be similar to flu. But infection during pregnancy can lead to miscarriage or stillbirth, or cause problems for the baby including blindness and seizures.
Pregnant women and people with lowered immunity are most at risk. It is recommended these groups don't empty cat litter trays, or use gloves if they have to. Changing the litter tray daily prevents the parasite reaching a stage that could infect people.
Allergies
Up to one in five people have an allergy to cats and this is increasing.
When cats lick their fur, their saliva deposits an allergen. When their fur and dander (flakes of skin) come loose, it can set off an allergic reaction.
People without severe allergies can still live with cats if they regularly wash their hands, clean surfaces and vacuum to eliminate dander. They can also exclude cats from areas they want to be allergen-free, such as bedrooms.
While cats can provoke allergic reactions, there is also evidence contact with cats can have a protective role in preventing asthma and allergic reactions developing. This is because exposure may modify the immune system, making it less likely allergic reactions will occur.
Susan Hazel, Associate Professor, School of Animal and Veterinary Science, University of Adelaide
This article is republished from The Conversation under a Creative Commons license. Read the original article.