Garlic contains allicin, a powerful anti-inflammatory compound that may speed healing time by accelerating the production of white blood cells and increasing the activity of macrophage cells in the blood. These cells engulf dangerous invaders that may cause infection and slow recovery time. Garlic also boasts sulfur-containing compounds that help to stimulate the immune system. Garlic also increases circulation to the affected area, allowing for higher nutrient delivery through the blood. When injured tissue receives an influx of nutrients and oxygen, it is able to heal more efficiently.