Experts are calling for an increased emphasis on health promotion as studies
draw links between high blood pressure and dementia.
The Women's Health Initiative Memory study of 1,403 participants, published in
the Dec. 2009 online issue of the Journal of Clinical Hypertension, is the most
recent report of its kind. It determined that people with hypertension (elevated
blood pressure) developed significant amounts of white matter lesions over the
eight years of the study.
Such lesions, usually the result of damage to the small blood vessels in the
brain, are a risk factor for dementia.
Hypertension is a major risk factor "not just for classical strokes, but also
for mini mini-strokes," says Dr. Frans Leenen, director of the hypertension unit
at the University of Ottawa Heart Institute. "A mini-stroke on its own doesn't
do much, but several together over the years, each closing tiny blood vessels in
the brain, cause progressive changes in personality, mood and cognition,
ultimately leading to a form of dementia called vascular dementia."
Hypertension is a growing concern in many age groups, including younger adults.
According to the annual report of the Heart and Stroke Foundation released in
January, rates of high blood pressure among all Canadians rose 77 per cent
between 1994 and 2005. In adults from age 35 to 49, the prevalence of high blood
pressure soared by 127 per cent. Leenen says between 60 and 70 per cent of
people over 60 have high blood pressure.
Sylvia Wassertheil-Smoller of the Albert Einstein College of Medicine in New
York, a lead researcher on the WHIM study, says although "we don't know whether
hypertension treatment will prevent white matter lesions from developing, we do
have suggestive evidence that the progression of these brain lesions can be
slowed by anti-hypertensive therapy.
"The bottom line is that we don't know how to prevent dementia, but controlling
blood pressure is one way, probably the only way at the moment. We know how to
control hypertension. Yet the majority of people who have it don't do anything
"The important message," says Dr. Christopher Patterson, chief of geriatric
services at Hamilton Health Sciences, "is that this is just another good reason
for making sure your blood pressure is treated and that you live a healthy
lifestyle. Risk factors such as high blood pressure, being overweight and having
a sedentary lifestyle are not additive. They multiply. The key is a healthy
Dr. Howard Bergman, scientific director of the Fonds de la recherche en sante du
Quebec and chair of a provincial task force on Alzheimer's disease, strongly
advocates individual health promotion to protect against the devastating impact
of cognitive decline.
"If you want to protect against Alzheimer's disease," says Bergman, "you are
really talking about all the lifestyle issues: not smoking, not drinking too
much, nutrition, protecting your head from brain injuries and the early
detection and control of hypertension and diabetes.
Source : Canwest News Service