Dementia linked to high cholesterol, Australian researchers find

The Heart Research Institute’s Ashish Misra is behind the world-first discovery which opens the door for GPs to calculate a person’s risk of the neurodegenerative disease

Nurse Megan Piper has a history of high cholesterol and dementia in the family. Picture: Jane Dempster.

The moment her mother was diag­nosed with dementia 10 years ago marked the start of a long goodbye for Megan Piper, who is hoping a breakthrough discovery will help her curb the genetic ­disease.

In a world-first, researchers at the Heart Research Institute in Sydney have uncovered a link between high cholesterol and increased risk of dementia.

The study analysed data involving more than one million patients worldwide under the age of 65 and found high cholesterol increased the risk of cognitive ­decline.

Lead researcher at HRI Ashish Misra said the study found that “bad” lipids, called low-­density lipoprotein, were correlated with mild cognitive impairment that could then grow into something more sinister.

“If [patients] have high lipids, then that can cause mild cognitive impairment, Dr Misra said.

“Once they have mild cognitive impairment, around 50 per cent of patients develop dementia within five years.”

Dr Ashish Misra analysed the data of 17 global studies, involving more than a million patients to uncover the relationship between high cholesterol and dementia. Picture: Gaye Gerard

The established link has opened up opportunities for the prevention and early intervention of diabetes, with an inexpensive and easy blood test able to determine cholesterol levels.

Dr Misra said according to the data analysed, the normal cholesterol level is 5.17 millimoles per litre and each millimole per litre increase caused a person 8 per cent more dementia.

“I would definitely suggest that when we’re getting older and we reach 50, we have a blood report every six months … if we have high cholesterol or LDL level in our blood, then those GPS should be doing more testing,”

For Ms Piper, 52, a nurse with three children, her mother’s experience with Alzheimer’s disease and her family history of high cholesterol encouraged her to cook healthy meals, go for brisk walks and practise pilates five days a week.

“Being the person in the family as well with a medical understanding and a nursing history, I’ve had appointments and asked a lot of questions about genetics and about probabilities … But this is the first time we know an unhealthy, overweight lifestyle can contribute to dementia,” she said.

While her mother was diagnosed at 70, she’d had high cholesterol in her 30s, despite living an active lifestyle and eating a Mediterranean diet. “I’ve heard it described as the long goodbye and I think that is really a perfect way to talk about it … it’s just little bit by little bit that they lose awareness,” Ms Piper said. “[My mother] would leave home trying to find [her husband], which would mean hours of us searching and asking local police to help find her.”

On last year’s Australian Institute of Health and Welfare estimates, more than 400,000 people live with dementia, almost two-thirds of whom are women.