Non-alcoholic fatty liver disease linked to higher dementia risk

Researchers from Sweden have found that people with non-alcoholic fatty liver disease had an increased risk of dementia. For people with this form of liver disease who also have heart disease or have had a stroke, their risk of developing dementia is even higher. The findings were published in the journal Neurology today (Wednesday 13 July).

Researchers looked at 30 years of national Swedish patient registry records. They identified a large cohort of people aged 65 and above who were diagnosed with non-alcoholic fatty liver disease – the build-up of fat cells in the liver.

These people were then matched with people without liver disease but are similar in terms of age, sex and city of residence at the age of diagnosis.

The researchers also looked at cardiovascular complications in these two groups of people, such as heart disease and stroke.

The study found that 5% of the people with non-alcoholic fatty liver disease were diagnosed with dementia, compared to 4.6% of the people without liver disease.

Adjusting for cardiovascular risk factors such as high blood pressure and diabetes, the researchers found that people with non-alcoholic fatty liver disease had a much higher rate of dementia.

Looking at the types of dementias, they found that non-alcoholic fatty liver disease is linked to higher risk for vascular dementia (caused by reduced blood flow to the brain), but not for Alzheimer’s disease.

People with liver disease who also had heart disease or stroke had much greater risk of developing dementia.

Dr Rosa Sancho, Head of Research at Alzheimer’s Research UK, said:

“This study found that having heart diseases or stroke may intensify the effect of liver disease on a person’s risk of dementia. This suggests that treatments targeting both non-alcoholic fatty liver disease and cardiovascular diseases may help reduce the risk of dementia. “Non-alcoholic fatty liver disease is often underdiagnosed because people do not always display symptoms so this study could be underestimating the strength of the link to dementia. “This form of liver disease and dementia share many common risk factors, such as high blood pressure, diabetes, and obesity. Future studies will need to explore the mechanisms underlying the link between non-alcoholic fatty liver disease and dementia. “This finding highlights the fact that our brains don’t operate in isolation from the rest of our body and improving our physical health can help to reduce our risk of dementia and support a healthy brain. Current evidence suggests that being physical and mentally active, staying socially connected, not smoking, only drinking in moderation, eating a balanced diet, and keeping cholesterol and blood pressure levels in check can all play a part in improving brain health. Find information and advice on brain health at www.thinkbrainhealth.org.uk”