Manganese rich foods - Natural painkiller

It's proven research that manganese rich foods help to relieve pain and acts as a mild pain killer, specific in dysmenorrhoea (menstrual pain).
Some of foods like amaranth seeds (rajgira), ragi, pineapple, papaya, gogu leaves, cardamom, cloves are rich in manganese and if eaten in premenstrual period or in menses. It's better to eat natural painkiller as a food instead of medicines.