Garlic is full of many beneficial nutrients that have been known for centuries. Garlic is very rich in antioxidants which help the body's protective mechanisms in case of oxidative stress. Taking high doses of garlic supplements may raise antioxidant enzymes in the body long term, and greatly reduce oxidative stress. This is especially the case when it comes to people with high blood pressure. Garlic may also prevent cancers, Alzheimer’s and dementia. It’s also known to boost the immune system and reduce cholesterol.