Dementia risk factors identified: Poor vision and high cholesterol

A large-scale study has identified poor eyesight and high cholesterol as two new risk factors for dementia. The study claims that eliminating these factors, along with 12 other previously recognized factors, could prevent almost half of all dementia cases worldwide. However, some of these factors are difficult to eliminate, and genetics and advanced age remain the biggest risk factors for developing dementia.

“Dementia may be one of the most significant health threats facing the nation.” Gil Livingston “The possibility of changing this and significantly reducing the number of people suffering from depression is crucial,” said researchers from University College London. [this] disease.”

A 2020 study identified 12 potentially modifiable risk factors for dementia, including hearing loss, depression, smoking, high blood pressure, heavy alcohol consumption, obesity, air pollution, traumatic brain injury, diabetes, social isolation, physical inactivity and lack of education.

Livingstone and 26 other dementia experts from around the world updated the list based on the latest evidence, retaining the 12 risk factors but adding two new ones: high levels of low-density lipoprotein (LDL) “bad” cholesterol before age 65 and untreated vision loss in later life.

The researchers included high LDL cholesterol based on several new findings, including: Analysis of 17 studies The study followed around 1.2 million British participants under the age of 65 for over a year.

The results showed that for every 1 millimole per liter (mmol/L) increase in LDL cholesterol, the incidence of dementia increased by 8 percent. In another study of similar size, High LDL cholesterol (above 3 mmol/L) has been linked to a 33% increased risk of dementia, on average, and this risk is most pronounced in people who had high LDL cholesterol in midlife. “So it really does matter how long you have it,” Livingston says.

The researchers suggest that this association may mean that excess cholesterol in the brain increases the risk of stroke and contributes to dementia. Cholesterol has also been linked to the buildup of beta-amyloid protein plaques in the brain, which is linked to Alzheimer's disease.

Untreated vision loss can: Analysis of 14 studiesThe study, which involved more than 6.2 million older adults who were initially cognitively healthy, showed a 47% increased risk of developing dementia over 14.5 years. In another analysis, the risk The decline in vision was mainly due to cataracts and complications from diabetes. [loss] “There's a risk because you're reducing cognitive stimulation,” Livingston said, even though some research suggests that such stimulation may make the brain more resilient to dementia.

The researchers then used their model to estimate what percentage of dementia cases worldwide could be prevented if each of 14 modifiable risk factors were eliminated. They found that hearing loss and high cholesterol had the greatest impact, each contributing about 7 percent of dementia cases, while obesity and excessive alcohol consumption had the least impact, each contributing 1 percent. If all factors were eliminated, the team estimated that about 45 percent of dementia cases could be prevented.

But just because these factors are associated with dementia doesn't mean they cause it, he said. Dylan Williams“So even if we target interventions at them, they may not prevent as much disease as we would hope,” said researcher David L. Schneider of University College London, who was not involved in the report.

These estimates are only population averages and don't capture individual-level risk, Williams says. So removing all factors from your life wouldn't necessarily halve your risk of dementia, which is heavily influenced by genetics and age. Eliminating many of these risk factors, like air pollution or lack of education, would also require public health interventions rather than individual changes, Williams says.