Runny nose, congestion, sore throat, sneezing. Yep, sounds like it could be a cold. While cold symptoms vary (and can also include headaches and fever), all colds are respiratory infections caused by more than 200 possible viruses. With so many viruses waiting to take hold, another way of thinking of it is that a cold is caused by a weak immune system that allows the virus to set in.However, there are numerous foods and nutrients that can play helpful roles in prevention or treatment of it. Including a variety of these seven foods in your diet to maintain (or regain) a healthy immune system.

SARDINES:-Fatty fish is high in omega-3 fats, which research shows helps reduce the risk of heart disease and inflammation in the body. In addition, a new animal study published in the Journal of Leukocyte Biology shows that omega-3s may also help boost the immune system by enhancing the functioning of immune cells. You might be surprised that sardines trump their fishy counterparts when it comes to omega-3s: A three-ounce serving of canned sardines provides 1,259 milligrams of omega-3s, while the same amount of rainbow trout has 905 milligrams, salmon has 840 milligrams and canned tuna has 196 milligrams. Sardines also provide other important nutrients to keep your immune system running strong. For example, a quarter-cup serving of BPA-free canned, sustainably wild-caught BELA sardines in olive oil contains 120 calories, 13 grams of protein and provides calcium and vitamin D for good health.

YELLOW BELL PEPPERS:-Oftentimes when people are feeling sick, the first thing they reach for is vitamin C. One of the best sources of vitamin C is a yellow bell pepper -- with one large one providing 568 percent of your daily value of vitamin C. Since it was first isolated in the 1930s, vitamin C has been thought to treat respiratory infections. Since then, research has shown that consuming vitamin C does not actually prevent colds, but dont snub your peppers yet -- vitamin C may play a role in helping to relieve cold symptoms. “Studies suggest that regular vitamin C supplementation at levels well above the daily value may help shorten a common cold’s duration and lessen symptom severity,” says Jackie Newgent, RDN. In addition, research shows vitamin C intake is particularly important to boosting the immunity of certain populations: the elderly, chronic smokers, extreme athletes and children.

MUSHROOMS:-Rich in B vitamins, selenium and antioxidants, mushrooms have long been thought to offer immune-boosting benefits. “Mushrooms have antiviral effects, and consumption of mushrooms may be associated with an increased production of cells that fight infections,” says Jackie Newgent, RDN. Reduced amounts of the mineral selenium have been associated with a greater risk of developing advanced flu symptoms. And the B vitamins in mushrooms (niacin and thiamin) help keep the immune system strong. “Maitake and shiitake mushrooms, in particular, contain plant nutrients that seem to have immune-boosting ability. Saute shiitake mushrooms and stuff them in an omelet with a little goat cheese and fresh herbs, or sprinkle fresh maitake mushrooms with olive oil, salt and pepper, and then grill them and serve on a salad or top with an egg,” adds Newgent.

ALCOHOLIC BEVERAGES:-Have you ever wondered (or heard) that since alcohol is used to sterilize things outside your body, it might also help fight infections inside your body? The reality is that it is not true. Drinking alcohol once you are sick will not wipe out the virus. In fact, drinking alcohol in an attempt to treat a cold could lead to dehydration, worsen your symptoms of congestion and may interact with certain medications. However, a daily drink might make you less likely to get sick in the first place. Some studies show that regular and moderate consumption of alcohol may be associated with lower prevalence of the common cold.Moderate alcohol intake is generally defined as up to one drink a day for women and up to two drinks a day for men.

CHICKEN SOUP:-Yes, there is science behind the age-old adage that chicken soup helps cure the common cold! At the most basic level, the warm liquid is hydrating, helps loosen mucus and eases sore throats. In addition, preliminary research shows the ingredients in chicken soup may have unique medicinal properties.The broth, vegetables and chicken in a soup tested in a lab all showed anti-inflammatory properties. The movement of neutrophils (white blood cells) and found they were reduced by chicken soup, suggesting the soup might have an anti-inflammatory effect, which may ease symptoms and shorten upper respiratory tract infections. “Grandmas Soup,” the recipe used in the study includes chicken, onions, sweet potatoes, parsnips, turnips, carrots, celery stems, parsley, salt and pepper.

CITRUS FRUITS WITH PEEL:- Since citrus fruits are packed with vitamin C, enjoying them regularly is a good idea to keep your immune system running strong. One medium orange provides 117 percent of your daily value for vitamin C. Antioxidants like vitamin C boost immunity by fighting cell-damaging free radicals.But when it comes to citrus fruits, there may be an added benefit for those suffering from severe colds. A natural chemical found in citrus fruit peels, limonene, could play a potential role in the treatment of bronchitis, though more research in this area is needed.Preliminary data also show that limonene may help fight cancer and aid in weight loss. An easy way to include the citrus peel in your diet is to make a citrusy vinaigrette: Whisk together fresh orange juice and a generous pinch of grated orange peel (zest) with olive oil and a squirt of lemon juice.

GINGER:-Whether you prefer it in your holiday cookies or your beef-and-broccoli stir-fry, ginger is a versatile spice with one of the longest medicinal histories. For more than 2,000 years Eastern medicine has recommended ginger to help cure and prevent numerous health conditions. Ginger has been recommended to cold-sufferers for thousands of years in Japan, China and in Ayurvedic medicine. Ginger tea is thought to be helpful at the beginning of a cold with no fever, and it may also help with nausea. Plus, having a warm cup of fresh ginger tea with honey and lemon juice can be a soothing way to loosen mucus and ease discomfort and nausea.