High cholesterol and untreated vision loss have been identified as new risk factors for dementia by a major report.

The Lancet’s third ‘commission’ on dementia, published at the end of last month, suggested that 45% of cases could be prevented or delayed by tackling 14 risk factors, starting in childhood.

A previous dementia commission in 2020 identified 12 of those risk factors – which included smoking, depression and traumatic brain injury – while the two new risks were revealed in July.

The report, written by 27 dementia experts, brought together findings of new research since 2020, with a focus on systematic reviews and meta-analyses.

Based on this, the Lancet commission has made 13 recommendations to individuals and governments to reduce dementia risk, such as preventing hearing and vision loss, using head protection in contact sports, and improving air quality.

According to the research, the number of people with dementia is set to almost triple by 2050 as people live longer.

However, the authors pointed out that in high-income countries such as the UK the proportion of older people with dementia has fallen.

They suggest that this reduction is due to people building ‘cognitive and physical resilience’ as well as having ‘less vascular damage’ as a result of healthier lifestyles.

The 14 risk factors are now as follows (newly identified risks in bold):

  • less education;
  • hearing loss;
  • hypertension;
  • smoking;
  • obesity;
  • depression;
  • physical inactivity;
  • diabetes;
  • excessive alcohol consumption;
  • traumatic brain injury;
  • air pollution;
  • social isolation;
  • untreated vision loss;
  • high LDL cholesterol.

Studies have found that these two new risk factors are associated with 9% of all dementia cases.

The report also estimated that the risk factors associated with the greatest proportion of people developing dementia in the global population were hearing impairment; high cholesterol; less education in early life; and social isolation in later life.

Professor Gill Livingstone, the lead author from University College London, said the report ‘reveals that there is much more that can and should be done to reduce the risk of dementia’.

She continued: ‘We now have stronger evidence that longer exposure to risk has a greater effect and that risks act more strongly in people who are vulnerable.

‘That’s why it is vital that we redouble preventive efforts towards those who need them most, including those in low- and middle-income countries and socio-economically disadvantaged groups. Governments must reduce risk inequalities by making healthy lifestyles as achievable as possible for everyone.’

NHS England’s national clinical director for dementia Dr Jeremy Isaacs said the report’s findings ‘offer real hope’ for reducing the number of people who live with the illness.

He said: ‘This research is really important as it suggests there are additional risk factors for dementia, which means that there are more opportunities for all of us to take action throughout our lives to reduce our risk of developing dementia or delay its onset.’

Dr Isaacs also emphasised the importance of a ‘timely diagnosis’ and said NHS staff have ‘worked hard’ to ensure the number of people with a diagnosis has risen to ‘a record level’ over the last year.

He also urged the public to encourage anyone with symptoms to visit their GP.

13 recommendations to reduce dementia risk

  • Provide all children with good quality education and be cognitively active in midlife.
  • Make hearing aids available for all those with hearing loss and reduce harmful noise exposure.
  • Detect and treat high LDL cholesterol in midlife from around age 40 years.
  • Make screening and treatment for vision impairment accessible for all.
  • Treat depression effectively.
  • Wear helmets and head protection in contact sports and on bikes.
  • Prioritise supportive community environments and housing to increase social contact.
  • Reduce exposure to air pollution through strict clean air policies.
  • Expand measures to reduce smoking, such as price control, raising the minimum age of purchase, and smoking bans.
  • Reduce sugar and salt content in food sold in stores and restaurants.

Source: The Lancet

A version of this article was first published by our sister title Pulse