How good or bad is your sense of smell? Your olfactory system could help determine who is at risk of dementia. Here’s what the scientists say.
Researchers from UC San Francisco tracked 1,800 participants in their 70s for a decade.
Their original aim was to uncover if their sensory functioning was directly linked to the development of dementia.
At the beginning of the study, all the participants were dementia-free, but 18 percent of them (328 subjects) developed dementia over the 10 years.
The results were published in the Alzheimer’s and Dementia: The Journal of the Alzheimer’s Association.
Willa Brenowitz, the lead author of the study said: “sensory impairments, particularly hearing and vision, may accelerate cognitive decline.”
The researcher continued to say this could be because sensory impairments increase “social isolation, poor mobility, and adverse mental health”.
Interestingly, the research team noted that a keen sense of smell had a stronger association against dementia than good hearing or vision.
In fact, the data showed that participants whose smell declined by 10 percent over the length of the study had a 19 percent higher chance of developing dementia.
This was a much stronger association than those who had lost their vision or hearing just as much.
Those who suffered from a loss of hearing and vision by the same amount only had a three percent increased risk of developing the brain disease.
Results were collected from cognitive testing done each year, alongside documented use of dementia medication and hospitalisations due to the brain disease.
The results also revealed that those who didn’t develop dementia showed no sensory impairments throughout the study.
The Alzheimer’s Society recognised that age is the “strongest risk factor” for developing dementia.
The charity noted that “six out of 100 people aged between 75 and 79 will have dementia”.
However, there is evidence that what you choose to do with your life could reduce your risk.
The charity commented: “Doing regular physical activity is one of the best ways to reduce your risk of dementia.”
Another way you could reduce your risk of developing the brain disease is to “eat a balanced diet”.
What does a balanced diet consist of? Alzheimer’s Society clarifies it means eating “at least five portions of fruit and vegetables every day”.
To eat protein at least twice a week could be incorporating beans, pulses, meat or oily fish to your diet.
And to limit your sugar and salt intake, as well as reducing any saturated fat.
Moreover, do eat starchy foods, such as bread, potatoes and pasta and stay well hydrated by drinking eight glasses of water a day.
Importantly, don’t smoke. “If you smoke, you’re putting yourself at much higher risk of developing dementia,” added the charity.
“Smoking does a lot of harm to the circulation of blood around the body, including the blood vessels in the brain, as well as the heart and lungs.”