Magnesium benefits heart health. When we are deficient in magnesium, it may cause a large role in poor heart health. Magnesium has many positive properties to it. It is able to improve heart rate and arrhythmias. It can reduce the size of blockages. It is proactive in helping to improve the energy production within the heart. It also reduces the demand on the heart by reducing peripheral vascular resistance and keeps blood clots from forming. Magnesium is an important supplement for our hearts.