In patients with hypertension, what was the effect of a daily exercise regimen on reducing blood pressure compared with a dash diet In one year?
is this a good PICO question?
Sorry, I have no idea what a PICO question is. You might want to post your question publicly; you're likelier to get help.
As for the study: you'd have to find a group of people with hypertension who would be willing to follow the DASH diet faithfully for one year and forego all exercise. And you'd have to find another group willing to exercise but forego the DASH diet. Would that mean they couldn't eat anything on the DASH diet?
I don't think anyone's physician would advocate participation in such a study. They'd be much more likely to encourage their patients to embrace a regimen of diet and exercise. If this type of study hasn't already been done, there's probably a reason for it.