In most cases high blood pressure, hypertension, is a disease of unknown cause. There are rare “secondary” causes such as hormonal abnormalities but more than 95% of cases are “primary”. The kidney regulates blood pressure by adjusting the filling of the blood vessels. The details of this “barostat” are not known. In “primitive” societies average blood pressure is very low but in “developed” societies high blood pressure occurs in up to 30% of adults and increasingly in children. Clearly there is huge environmental influence on the kidney barostat.
Serendiptiously a number of drugs have been discovered that alter the kidney barostat. In spite of the profound effect of lifestyle change on blood pressure all trials of hypertension drugs have not used lifestyle change as the first line of treatment, a clearly unethical approach.
ALLHAT is the biggest trial of hypertension drugs. It took 6 years with most subjects on two or three drugs to reduce systolic blood pressure by 11 mm Hg. This paper is not “free”, probably because no drug company would pay for it. Why? Because the results favoured the use of cheap diuretics instead of more expensive patented drugs.
In the landmark DASH (Dietary Approach to Stop Hypertension) trial the same result was accomplished in 6 weeks even with no weight loss simply by changing diet to the same sort of diet recommended to treat an prevent diabetes and atherosclerosis.
In the original DASH trial meals were prepared for the patients. The same group of investigators wanted to prove that the same result could be accomplished just by advising patients what to eat. The landmark PREMIER trial did just that. Note that the BP reduction was substantial even in the “control” group which was given just basic advice without follow-up. And all groups lost weight.
Now if every doctor who ever sees a patient with hypertension would do the same on every visit, hypertension would almost disappear and billions of dollars in drug costs would be saved. Of course the same lifestyle would prevent type 2 diabetes and atherosclerosis, saving many more billions of dollars.