Eating low fat dairy products, along with lots of fruits and vegetables on a regular basis, is associated with lower blood pressure. All of these foods are rich in magnesium, as well as calcium and potassium. A large clinical study of more than 8,500 women found that a higher intake of dietary magnesium may decrease the risk of high blood pressure in women. A few studies also suggest that magnesium supplements may help lower blood pressure, although not all studies agree.