text: Garlic – Like many plants, garlic is packed with powerful antioxidants. These chemicals neutralize free radicals (particles that damage our cells, cause diseases, and encourage aging) and may reduce or even help prevent some of the damage the free radicals cause over time. Among the compounds in garlic is allicin, which has been linked to fending off heart disease and the common cold. Because stress weakens our immune system, we need foods like garlic to improve our immunity.