Citrus fruits

  • Vitamin C contributes in increasing the production of white blood cells. The key cells to fighting infections

  • Because your body doesn't produce or store it, daily intake of vitamin C is essential for consistent good health

  • Fruits rich in vitamin C are oranges, lemon, amla, strawberries, kiwis, papaya

Yogurt

When selecting yogurt, look for ones that have "live and active cultures" printed on the label. According to the American Journal of Clinical Nutrition, these cultures can stimulate your immune system to help fight diseases.

Garlic

Garlic is found in almost every cuisine around the world. It adds a little zing to the food and it's a must-have for good health. Studies by the National Institute of Food Science and Technology have shown that garlic helps to lower cholesterol and may prevent hardening of arteries. Garlic’s immune-boosting properties seem to come from a heavy concentration of sulfur-containing compounds, such as allicin.

Almonds

Vitamin E is the key to a healthy immune system. Vitamin E is a fat-soluble vitamin, meaning, it requires the presence of fat to be absorbed properly. Nuts (especially almonds) are packed with vitamin E. A half-cup serving provides nearly 100 percent of the recommended daily amount.

Turmeric

A key ingredient in many curries, this bright-yellow, bitter spice has been used for years as an anti-inflammatory in treating both osteoarthritis and rheumatoid arthritis. A recent study published in the Journal of Ethnopharmacology demonstrates that high concentrations of curcumin, which gives turmeric its distinctive color, helps to reduce inflammation and fever.

Green tea

Green tea really has high levels of epigallocatechin gallate, or EGCG, another powerful antioxidant. The fermentation process black tea goes through destroys a lot of the EGCG. Green tea, on the other hand, is steamed and not fermented, preserving EGCG. If that wasn't enough, it's also a good source of the amino acid L-theanine. L-theanine aids in the production of germ-fighting compounds in your T-cells.