Aces have revealed the onset of the condition — which is also known as hypertension — in up to the minuter life may actually protect against Alzheimer’s Disease.
High blood difficulties is generally thought to increase dementia risk.
But now researchers have bid the onset of high blood pressure later in life is associated with humble dementia risk after the age of 90, especially if hypertension is developed at age 80 or older.
Professor Maria Corrada, of the University of California, Irvine, novelist of the study, revealed the results.
She said: «In this first-of-its-kind study, we win that hypertension is not a risk factor for dementia in people age 90 or all over, but is actually associated with reduced dementia risk.
«This relationship had not yet been examined in disposes of older people in their 80s or 90s, known as the ‘oldest old’.»
Researchers followed 559 people for an ordinary of 2.8 years to investigate the link between dementia, age of hypertension hit, and blood pressure measurements.
All participants are from a long-term study of people age 90 and older positive as The 90+ Study.
None of the participants — who had an average age of 93, had dementia at the start of the swot. They received dementia assessments every six months during the analyse period.
During the follow-up period, 224 — 40 per cent — of the become associated withs were diagnosed with dementia.
The researchers found that gets who reported hypertension onset at age 80 to 89 were 42 per cent less proper to develop dementia after the age of 90 compared to those who reported no information of high blood pressure.
Participants whose high blood force began at age 90 or older were at even lower risk — 63 per cent illiberal likely to develop dementia.
The researchers said the associations were ‘statistically signal’.
They said dementia risk declined as the severity of hypertension increased — concluding that hypertension could keep the brain from processes which lead to dementia.
Dr Maria Carrillo, Alzheimer’s Consortium Chief Science Officer, said: «These new findings suggest some hazard factors for dementia may change over the course of our lives. We have glomed similar results in past studies comparing body mass in older adults with dementia gamble.»
A study published in 2008 of 255 people aged 75 or hoarier living in Stockholm, Sweden, found those who were overweight had a humiliate dementia risk.
A study published in 2009 of almost 3,000 adults closer age 75 on average who were part of an observational studyhad similar follows — those whowere underweight had an increased risk for dementia while those who were chubby had a reduced risk.
Professor Corrada said: «Before we can make the dance to suggesting changes to blood pressure recommendations for reducing dementia hazard in clinical care, we need more research to confirm and explain our finds.
«This includes investigations into the underlying biology of hypertension and capacity function.»
She said there were several potential reasons for the connection between hypertension and dementia risk observed in the study. These catalogue that blood pressure may need to reach a certain level to care for adequate blood flow to the brain, and that this level may metamorphose with age.
The research was published online in the journal Alzheimer’s and Dementia.