Papayas
With 250 percent of the RDA of vitamin C, a papaya can help kick a cold right out of your system. The beta-carotene and vitamins C and E in papayas reduce inflammation throughout the body, lessening the effects of asthma.

Cranberries
Cranberries have more antioxidants than other common fruits and veggies. One serving has five times the amount in broccoli. Cranberries are a natural probiotic, enhancing good bacteria levels in the gut and protecting it from foodborne illnesses.

Grapefruit
Loaded with vitamin C, grapefruit also contains natural compounds called limonoids, which can lower cholesterol. The red varieties are a potent source of the cancer-fighting substance lycopene.