Garlic is low in calories and rich in vitamin C, vitamin B6 and manganese. It also contains trace amounts of various other nutrients.
Garlic supplements help prevent and reduce the severity of common illnesses like the flu and common cold.
High doses of garlic appear to improve blood pressure for those with known high blood pressure (hypertension). In some instances, supplements may be as effective as regular medications.
Garlic supplements seem to reduce total and LDL cholesterol, particularly in those who have high cholesterol. HDL cholesterol and triglycerides do not seem to be affected.
Garlic contains antioxidants that protect against cell damage and aging. It may reduce the risk of Alzheimer's disease and dementia.
Garlic has known beneficial effects on common causes of chronic disease, so it makes sense that it could also help you live longer.
Garlic may improve physical performance in lab animals and people with heart disease
Garlic was shown to significantly reduce lead toxicity and related symptoms 
Garlic appears to have some benefits for bone health by increasing estrogen levels in females