Lemons may just look sour, but they are actually much healthier than many think. One lemon can provide a significant portion of the daily requirement of vitamin C. It helps support the immune system and protect cells from damage. Lemons also improve the absorption of iron from food. This is especially important for those who eat little meat. In addition, studies show that the scent of lemon can reduce fatigue and improve mood. An interesting fact: once in Europe, lemons were considered a real luxury, and only very rich people could afford them.