A review conducted at Brigham Young University, Provo, Utah looked at six clinical trials regarding the benefit of magnesium supplements in patients with coronary heart disease. Magnesium dosages ranged from 130 to 800 milligrams per day. A higher magnesium intake was associated with reduced risk of heart disease in male subjects but there was no decrease in the development of CHD in women who also had a high magnesium intake. The researchers suggested that “There is a possible association between a modestly lower risk of CHD in men and increased magnesium intake; therefore, it is reasonable to encourage diets high in magnesium as a potential means to lower the risk of CHD.” See http://www.raysahelian.com/magnesium.html
Comments: I don't know why this study did not find magnesium was of benefit to women with heart disease, I still think it is worthwhile for women who have heart disease to take 100 to 200 mg a day of this mineral since it is quite safe.