Previous studies have put cognitive problems suffered by some Alzheimer's patients to low blood pressure (arterial hypotension).
However, the new study led by researchers from Osijek Medical Faculty in Croati suggests that as the patient's memory fails, they forget the causes of anxiety and worry that was causing high blood pressure: failing memory causes hypotension.
"An important question is would reduction of stressful memories and of stress exposure in everyday life help diminish the risk of getting hypertension or metabolic syndrome in the years to come," said study's author Dr Sven Kurbel of the Osijek Medical Faculty in Croatia.
If confirmed by further studies, this will affect how doctors treat the elderly, helping to target drugs more effectively and reduce risks of strokes and heart attack.
It also suggests that heart disease could be substantially reduced in old people simply by making them happier about themselves and their lives.
The study proposes that some people suffering from Alzheimer's disease experience a reduction in their high blood pressure because of cognitive decline.
The study is published in Bioscience Hypotheses.