Garlic

Garlic is incredibly beneficial to your immune system because it offers a triple-whammy: it's antibacterial, antiviral and anti-fungal. We should be eating garlic every day. One of the best things about garlic is that bacteria, viruses, and yeast build up no resistance to it, unlike with synthetic antibiotics. Garlic contains antioxidants that protect against cell damage and ageing. It may reduce the risk of Alzheimer's disease and dementia. Garlic contains allicin, a chemical that is anti-carcinogenic. It also has been shown to lower LDL, lower total cholesterol, lower blood pressure, reduce your risk of blood clots and stroke, lower homocysteine, and even prevent insect bites --including mosquitoes and ticks. 
Garlic was shown to significantly reduce lead toxicity and related symptoms in one study.

For optimal benefits, garlic should be fresh since the active ingredient is destroyed within one hour of smashing the garlic cloves. In other words, garlic capsules are basically useless. Fresh garlic can be kept on hand to add to so many dishes. It even comes in it's own protective packaging!