The ability to smell appears to be closely linked to dementia, according to new research which has some interesting implications for early intervention.
The study followed 18,000 participants in their 70s for 10 years.
None of the participants had dementia when they started – by the end 18% had been diagnosed.
Researchers were able to identify a link between mild and moderate sensory impairment and an increased risk of dementia.
Of all the senses, they found smell was found to be most closely linked to dementia risk.
Participants whose smell declined by 10% were 19% more likely to be diagnosed during the period, compared to an increased risk of 3% for vision, hearing and touch.
So, why is this the case?
The study’s authors say sensory impairments could be due to underlying neurodegeneration or the same disease processes as those affecting cognition, such as stroke.
Otherwise, they argue sensory impairments, particularly hearing and vision, can accelerate cognitive decline, either because they directly impact on cognition or indirectly because they increase the risk of social isolation, poor mobility and adverse mental health.
However, this new knowledge means doctors can target people with poor multisensory function for early intervention, knowing that they are at higher risk.
Good news.
