Working on night shifts is known to cause health issues including heart disease, diabetes and obesity. A new study has found that it can affect brain health too.

The latest study from York University in Canada says working on the night shift can cause cognitive impairments and memory loss in middle-aged and older adults. The night shift refers to working outside the traditional 9 a.m. to 5 p.m. working hours.

Researchers conducted cognitive function tests on 7,811 participants and evaluated them based on self-reported information about employment and work schedules.

Around 21% reported doing some kind of shift work during their career. When researchers compared the values of cognitive tests, they found people exposed to night shift work in their current job or during their longest tenure had higher rates of cognitive impairment than those who only did daytime work.

The findings suggest working on night shifts causes 79% higher rates of cognitive impairment in people.

"The study findings suggest a potential link between shift work exposure and cognitive function impairment. We speculate that disruptive circadian stimuli may play a role in neurodegeneration contributing to cognitive impairment; however, additional studies are needed to confirm the association between shiftwork and cognitive impairment, as well as any physiological pathways that underlie the mechanism," the researchers said in a news release.

Researchers believe shift work disrupts the circadian rhythm in middle-aged and older adults and this affects their cognitive function.

Circadian rhythm is a 24-hour cycle that is part of the body's internal clock, which gets reset every day by the sun's cycle. However, too much or too little sunlight exposure can disrupt the circadian rhythm. The disruption can lead to insomnia and mental health issues.

Studies show that disruption of the body's internal clock can also lead to chronic diseases, depression, obesity, diabetes, cardiovascular problems and headache disorders.