A study in Scotland showed that at-risk men (overweight, hypertensive, with abnormal lipid patterns benefited from drinking cranberry cocktail daily. Their blood pressure dropped and their lipids improved (LDL dropped, HDL rose.)
Cranberries are a great source of antioxidants, and are high in vitamin C. The blood pressure effect could be because Vitamin C is a diuretic and diuretics lower BP, or the cranberry juice may have a direct effect on BP.
Commercial cranberry juice cocktail contains artificial sweeteners which have recently been suspected as possibly confusing the brain about hunger pangs: they do not convince the brain that you should stop eating. So weight gain may be a problem. In the Scottish study their was weight loss, but that happens often just because patients know they are being observed and measured. And on principal we are against artificial anything.
Our experience, although not a clinical trial, is that a mixture of orange juice and cranberry juice is just as effective as cranberry cocktail, and is satisfying from the hunger point of view.
Cranberry juice is bitter and needs some help to make it palatable. 2/3 orange juice to 1/3 cranberry juice passes the taste test for our volunteers.
We recommend 1/2 cup of this mixture twice a day.
If the BP effect is partly because of the vitamin C diuretic effect, the orange juice adds to this, being high in vitamin C.
Try taking a coenzyme Q 10 at the same time: it also acts on BP and lipids.