We’ve been getting some real health shocks in recent years.
The first came when studies showed people with high cholesterol are smarter, have a reduced risk for dementia and live longer.
Then three major studies demonstrated that being overweight or even obese can be protective against dementia.
And now a new study has really thrown the cat among the pigeons. It suggests hypertension (high blood pressure) can substantially reduce the risk of Alzheimer’s under some circumstances.
The reasons for each of these seemingly paradoxical findings have to do with your age…
Hypertension May Have a Benefit If You’re Over 80
For the blood pressure study, 559 people aged 90 or over without dementia were included from a long-term study that began in 1981.
During the follow up period of nearly three years, 224 developed dementia.
Compared to those who did not have hypertension, the ones who developed the condition in their 80s had a 42% lower dementia risk, while the risk reduction for those past 90 years of age was 63%.
The study, published in Alzheimer’s & Dementia in January 2017, concluded that, “Developing hypertension at older ages may protect against dementia.”
This is the same hypertension that can cause blood vessels in the brain to leak, narrow or become blocked. The damage caused by high blood pressure reduces blood supply and leads to cell death. This in turn creates problems with thinking, reasoning and memory.
So what is the explanation for the protective effect of high blood pressure if it begins late in life?
Improved Blood Flow to the Brain
Lead author Maria Corrada, Professor of Neurology at the University of California, Irvine, suggested this explanation:
“We believe that it may be because blood vessels become stiffer with age [and] a high blood pressure is needed to pump blood to the brain. It’s a matter of creating enough pressure to get blood to oxygenate the brain adequately.”
Her sentiments were echoed by Dr. Sam Gandy, Professor of Neurology and Alzheimer’s Disease Research at Mount Sinai Hospital in New York.
He believes that high blood pressure should be divided into at least two types.
“We usually think of the young adult onset form, which, if untreated, can damage heart, kidney, eye and brain blood vessels.
“A second class may be late-life hypertension, which is driven by a brain in distress. This distressed brain, through neurological mechanisms, could be causing blood pressure to rise in an attempt to improve blood flow and relieve distress.”
Risk Factors May Depend on Your Age
Dr. Maria C. Carrillo, Chief Science Officer at the Alzheimer’s Association, commented on the findings by saying that “some risk factors for dementia may change over the course of our lives.”
In other words, strategies that apply for one age group may not relate to another.
This would also explain why attempts to treat late-life hypertension have not reduced the incidence of dementia.
Biological changes that come with aging mean recommendations may have to be adapted according to whose needs are being addressed.
Attempting to control high cholesterol in older people may be a bad idea when cholesterol is needed to protect against cancer, a disease that becomes more likely with age, and infectious diseases like pneumonia, which older people are more susceptible to.
Being overweight may also be beneficial above a certain age because fat reserves are an important source of energy and aid immunity. Extra pounds may offer protection when you fall ill and help with recovery. The operative word there is “may.” Don’t go on an eating binge because your read somewhere that fat is now okay. It’s not.
Does This Mean Anything for Patients Right Now?
First off, one study blood pressure study doesn’t settle a complicated question like this. Results may vary from one study to the next.
As far as I know, no doctor has yet tried to apply this blood pressure finding in his practice. It sounds as if a rise in blood pressure that begins after the age of 80 should be observed and monitored, not treated with drugs.
I’m no fan of drug treatments for high blood pressure anyway. A daily walk and meditation (or related practices) should be tried first. Another problem is that high blood pressure is over-diagnosed and over-treated.
The medical profession has set the bar quite low, and what used to be considered a healthy blood pressure is now considered a disease. In this, as in many things, don’t be too sure the MDs know what they’re talking about.
It’s not clear that science is on the side of the new benchmarks – which have greatly benefited the big drug companies. Just by coincidence, I’m sure.
Dr. William Campbell Douglass, a famous medical maverick, used to maintain that high blood pressure was a danger only if it was extremely high. Most cases of so-called high blood pressure, he said, should be left untreated.
I don’t know if science is on his side, either, but I suspect if you’re healthy in general then your blood pressure, whatever it is, will be healthy as well. Take a walk, put the cookie down, take a vitamin, learn to relax: good advice in all times and all places.