Having a CAT could make you frail in old age, researchers warn

Cat owners may be at greater risk of becoming frail in old age, a study suggests.

Researchers in the US and Spain took blood samples from 600 people over 65 and found that two-thirds showed signs of previous infection with a parasite spread by cats.

Analysis suggested that those with a severe infection were more likely to be frail – meaning they suffer from reduced muscle strength and fatigue and take longer to recover from mild health problems.

Experts suggested the bug can cause inflammation and muscle wasting, which are signs of frailty.

They said their findings are not evidence that the parasite causes vulnerability, but that there is a “compelling association” that needs further investigation.

The team, from the University of Colorado Boulder, University of Maryland and the University of A Coruña in Spain, looked at the effects of Toxoplasma gondii (T. gondii).

About one-tenth of people in the US and up to 65 percent of people in other countries are infected with T. gondii. According to the researchers, the percentages are often much higher in older people.

Once people are infected with the parasite, they can carry it for a long time – possibly even their entire lives. However, only one in ten develop symptoms, including a flu-like illness, swollen glands and muscle aches.

T. gondii reproduces in the intestines of cats, meaning owners of infected cats are at risk of exposure when they change their litter box. Cat feces can also contaminate soil, water and food.

The team took blood samples from 601 Spanish and Portuguese people over 65 and measured their vulnerability.

This included recording their unintentional weight loss, fatigue, loss of cognitive acuity and other indications of declining health.

Results, published in The journals of gerontologyshows that 67 percent of the participants had markers in their blood of a latent infection with T. gondii.

And those who had a higher concentration of antibodies against the parasite were significantly more likely to be vulnerable, according to the researchers.

High levels of antibodies in the blood may reflect a more virulent or widespread infection, multiple infections or recent reactivation of a latent infection, they said.

Vulnerable people with high T. gondii seropositivity also had higher levels of certain inflammatory markers, suggesting the parasite could worsen inflammation – which previous studies have linked to fueling frailty.

In addition, T. gondii is found in muscle tissue, which could accelerate age-related muscle loss, the researchers said.

Dr. Christopher Lowry, study author and professor of integrative physiology at CU Boulder, said, “We often think of T. gondii infection as relatively asymptomatic.

‘But this study highlights that for some people it could have significant health consequences later on.’

According to the U.S. Centers for Disease Control and Prevention, people can be exposed to T. gondii in addition to litter boxes through contaminated water or dirty vegetables, or by eating undercooked pork, lamb or other contaminated meat.

In an evolutionary trick that benefits the parasite, rodents infected with T. gondii tend to lose their fear of felines, making it easier for cats to catch them, researchers said.

People who are infected also often exhibit risky behavior. Research shows they can be more impulsive and more likely to get into car accidents.

They also suffer more often from schizophrenia, certain mood disorders, cognitive problems and are more likely to commit suicide, according to previous studies by the researchers.

To a T. gondii infection, the researchers urged cat owners to change their litter box daily and always wash their hands afterwards.

People should also avoid eating undercooked meat and rinse fruits and vegetables before consuming them.

Pregnant women and people with weakened immune systems – who are most at risk from T. gondii – should avoid changing the litter box, keep their cats indoors and avoid stray cats.