People with unhealthy levels of cholesterol are at increased risk of developing Alzheimer's disease, a new study suggests.
Researchers at the University of California found that people with "bad" cholesterol in their blood stream typically had higher a greater concentration of amyloid plaque tangles in their brain.
It is believed that these plaques affect the brain's circuitry and are one of the main reasons people acquire the cognitive condition.
The exact cause of Alzheimer's is yet to be determined, but this study suggests that poor dietary habits can increase a person's risk.
In contrast, people who consumed high quantities of "good" cholesterol – such as that available from olive oil and nuts – were found to have lower levels of amyloid tangles.
"Unhealthy patterns of cholesterol could be directly causing the higher levels of amyloid known to contribute to Alzheimer's, in the same way that such patterns promote heart disease," said professor Bruce Reed, who led the study.
"Our study shows that both higher levels of good cholesterol and lower levels of bad cholesterol in the blood stream are associated with lower levels of amyloid plaque deposits in the brain."
He added that the research could help to find new ways in which the development of Alzheimer's can be reduced.
This could include encouraging people to lower their cholesterol levels earlier in life.
The study involved 74 men and women aged over 70 years.
Dr Laura Phipps, science communications manager for Alzheimer's Research UK, said despite the study's findings, people are not advised to begin take cholesterol lowering statins in an attempt to cure Alzheimer's.
As well as increasing the risk of dementia, high levels of cholesterol can also narrow the arteries as well as cause heart attack, stroke or mini-stoke (transient ischemic attack).
Doing regular exercise, eating a healthy diet and quitting smoking are recommended ways of lower cholesterol.
Find out more about Alzheimer's disease care at Barchester homes.