Major surgeries pose a greater risk of patients developing Alzheimer's disease, concludes a new study at Imperial College, London.
Experiments conducted on mice revealed changes in their brains, similar to those observed in humans with dementia, when the animals are operated on.
The researchers suspect the same effect could occur in humans after surgical procedures and are now to start a new study to further explore the theory.
The latest research showed that the brains of mice who underwent a surgical procedure showed the presence of protein "tangles" in the brain which are associated with Alzheimer's disease in humans.
Because normal mice do not develop Alzheimer's disease, the new two-year study, also being led by Imperial College, will examine genetically modified mice, in an attempt to see whether the tangles - clusters of protein that form in nerve cells - which are present after surgery go on to trigger the onset of dementia.
The study will also examine whether the use of certain drugs - such as statins, used to protect against heart disease - and the active ingredient of a herbal remedy called Celastrol, could reduce the risks for those undergoing surgery.
In the recent study on mice, Celastrol was seen to reduce inflammation in the brain.
Researchers said if either drug appeared to lower the risks of dementia in modified mice undergoing surgery, further trials would be required to see if this worked in humans, and also to see if it could protect the brains of the wider population, not just those undergoing operations.
"The data has shown for some time that some elderly people who undergo surgery, especially heart surgery, can develop cognitive dysfunction, which can mean memory loss, and a loss of focus but it isn't clear how much of that is short-term, and how much long-term," the Telegraph quoted Dr Daqing Ma, the lead investigator on the research, as saying.
"Some people go on develop dementia, which can damage lives and mean an early death, but we don't know if there is a link with the cognitive dysfunction suffered post-surgery," Ma added.
The research is due to be published in the journal Critical Care Medicine next month.