A new study is challenging the way the link between dementia and high blood pressure is interpreted. The work carried out by the University of California, Irvine, does not suggest that high blood pressure isn’t a risk factor for dementia for the majority of a person’s lifetime. What is interesting, however is that after 80 years of age, it could protect against Alzheimer’s disease.
The research discovered that those who developed high blood pressure between the ages of 80 and 89 had a lesser chance of developing Alzheimer’s in the following three years. This was in comparison to people of the same age with normal blood pressure levels.
Blood pressure is an estimate of how hard the heart is working to pump blood and over time, someone with high blood pressure is risking damaging the organ and their blood vessels. The brain can suffer as a result, because it needs a constant supply of oxygen and nutrients from the blood.
Extreme cases of high blood pressure can lead to a stroke or vascular dementia, but there is also a link to Alzheimer’s. Damaged blood vessels in the brain can contribute to the onset of the disease, due to a lack of oxygen, but also waste products not being removed properly. These, including β-amyloid, can build up and cause problems.
As many previous studies have looked at blood pressure in middle age and the correlation with dementia later on, this new research into older people is fascinating. The findings reflect the belief that blood pressure changes across a person’s lifespan and as a person ages, their body is less able to cope with fluctuations.
The condition known as postural hypotension, which is common in the over-70s, is thought to be a response to an age-related decrease in blood pressure. It supplies extra blood to the brain and could therefore help to ward off Alzheimer’s in older people.
What this newest research suggests, when added to the already existing bank of information, is that it’s best to stick to the Goldilocks range when it comes to blood pressure. This means maintaining a level that is neither too high nor too low.
It is an area that is very interesting, however, and since dementia is an increasing problem in an ageing population, there are likely to be further studies in the future. What is clear is that there is still a lot to learn about the condition and how it can be prevented.