Traditionally an issue for older people, blood pressure is rising among younger adults. An NIH study of more than 14,000 men and women between the ages of 24 and 32 found that nearly one in five had high blood pressure. That number is about five times higher than in previous studies. Other research, published in the American Heart Association's journal Hypertension, found that magnesium effectively lowers blood pressure. In clinical trials with a total of more than 2,000 people, daily magnesium supplement doses ranged from 240 to 960 mg.