According to two studies, untreated high blood pressure and vision impairment can increase the risk of dementia. A study published in the journal JAMA Ophthalmology has found that nearly one in five dementia cases could be attributed to vision impairment.
Researchers looked at the prevalence of dementia and one of three main types of vision impairment, including near visual acuity, distance visual acuity or contrast sensitivity in 2,767 people aged 71 and older.
About 19 per cent of dementia cases could be attributed to one or more types of vision loss, suggesting that dementia could have been prevented in nearly 20 per cent of cases if vision problems had been addressed. Nearly 90 per cent of vision problems in older people are preventable or correctable, according to researchers.
The second study published in the journal Neurology finds that untreated high blood pressure can increase the risk of Alzheimer’s. Researchers followed 31,250 people from 14 countries with an average age of 72 for around four years. Of them, 1,415 developed Alzheimer's disease during follow up.
The study found that 9 per cent of the participants had untreated high blood pressure, 51 per cent were taking blood pressure medications, and 36 per cent did not have high blood pressure. People with untreated high blood pressure had a 36 per cent increased risk of Alzheimer's disease compared with people without high blood pressure, and a 42 per cent increased risk of Alzheimer's when compared with people on blood pressure medication.
"These results suggest that treating high blood pressure as a person ages continues to be a crucial factor in reducing their risk of Alzheimer's disease," the study said.