0217 GMT February 19, 2020
Scientists said a history of the medical condition was a 'major risk' in someone's chance of developing the devastating brain disorder, dailymail.co.uk reported.
And it was even more of a risk than smoking, not exercising or being overweight or obese, the researchers claimed.
Excessive cholesterol could contribute to the development of the plaques in the brain which cause Alzheimer's — the most common form of dementia.
The finding adds to past research warning about the dangers of high cholesterol, which comes from foods with a lot of saturated fat such as dairy and red meat.
And the scientists said over-60s should eat fewer of these foods to try and reduce their risk, as well as exercise more often.
Researchers at University of Indonesia studied the health of 106 over-60s in Jakarta to determine what was most likely to affect their risk of dementia.
They considered their level of education, history of diabetes, cholesterol, social activities, physical exercise, smoking, body weight and depression.
'Based on this research, a history of high cholesterol is the most influential factor for dementia incidence in the elderly population,' the authors, led by Dr. Junaiti Sahar, said.
“Elderly individuals with a history of high cholesterol ratio have a 3.2 times greater risk of dementia compared to their peers without a history of high cholesterol.
“Moreover, high cholesterol can increase the risk of Alzheimer's disease by creating more plaque on the brain where 62 percent of plaque occurs in low cholesterol and 86 percent in high cholesterol.”
Cholesterol is a fatty substance found in the blood which is normal but can become dangerously high in people who eat unhealthily and don't exercise.
High levels of it can cause problems with blood circulation because it builds up on the inner walls of arteries, meaning blood flows less efficiently and blood pressure rises.
Past research has linked high levels of cholesterol to dementia through the formation of clumps of protein in the blood.
Cholesterol has been found to trigger the development of these toxic 'plaques' and, if they form in — or travel to — the brain they can build up there and lead to Alzheimer's.
Alzheimer's causes more than six in 10 cases of dementia, which affects at least 850,000 people in the UK and 5.8 million Americans.
In their study the Indonesian researchers found 75 percent of their participants had high cholesterol levels.
Among those who had a history of high cholesterol — a group in which there were 24 people — people appeared to have a 50/50 chance of getting dementia.
Whereas those who didn't have a history of high cholesterol had a 39 percent chance of having dementia.
These results, they said, were not statistically significant, but they still concluded that a history of high cholesterol was a 'major risk factor for dementia'.
Their adjusted figure showed that, when someone's smoking habits, weight, exercise, blood pressure and education were taken into account, a history of high cholesterol increased the dementia risk by a factor of 3.2.
Meanwhile, dementia risk was increased by 2.2 times by smoking, 2.3 times by a lack of exercise and three times by being poorly educated.
Sahar's team added, “Elderly individuals could enhance their quality of life by reducing their intake of high cholesterol foods, having regular cholesterol screenings, and doing physical exercise.”
They didn't specify which foods should be cut down on but those known to raise cholesterol include processed or fatty meats, cheese, butter and baked goods.
The research was published in the journal Enfermería Clínica.
Government advice limits the average British adult to between 200 and 250 calories from saturated fat each day — equal to about 31grams of butter.
Too much saturated fat is feared to increase the risk of heart problems because it's known to raise cholesterol and potentially build up in the blood vessels.