The human body has its own defense mechanism to fight disease-causing pathogens and prevent illnesses. This mechanism comprises cells, tissues, organs, and cell products, like antibodies, which are collectively known as the immune system of the body. This system identifies disease-causing microbes, and destroys them to protect the body from their attack. A strong immune system can perform all these functions perfectly, whereas a weak one may make the body prone to infections. In short, a healthy immune system helps you lead a healthy life. There is no single, sure-shot way to boost the immune system, as various factors, like diet, lifestyle habits, age, etc., are linked to its function. Most of us do not realize the importance of the immune system during the pink of our health. Once this system gets weakened, it fails to protect the body from diseases. There are so many factors that are linked to healthy functioning of the immune system. They include adequate exercise, balanced diet, good hygiene, adequate sleep, good mental health, and ideal body weight. The most important among them is a healthy and balanced diet, which includes foods that boost immunity. There are many natural immune system boosters, like fruits, vegetables, mushrooms, and fish. Herbal ones include garlic, basil, ginseng, and sage. As there is no specific food or herb, which can provide you with all the minerals and vitamins to boost the immune system, a balanced diet is very much important. Given below are some of the vital factors that can affect the immune system. This is one of the important aspects of healthy living. Regular exercise helps you maintain a healthy body weight, lower cholesterol levels, and improves circulation and cardiovascular health. Physical activity helps the white blood cells and antibodies to move faster throughout the body, as it increases the rate of blood circulation. It will also help eliminate bacteria and other disease-causing microbes, through inhalation and increased output of bodily wastes. Exercise increases the rate of body temperature that may prevent growth of bacteria and other such pathogens. A daily, brisk walk for around 30 minutes may prove useful to boost your immune system. It is impossible to name a single food item that is sufficient to maintain a healthy immune system. A healthy concoction of nutrients is required for this purpose, and that can be achieved through a balanced diet only. Foods that are rich in Vitamin C, Vitamin E, zinc, carotenoids, bioflavonoids, selenium, and omega-3 fatty acids, are effective immune system boosters. But some vitamins and minerals can be absorbed into the body, only with the help of other nutrients. Vitamin C, which is very much important for the immune system, needs the help of calcium and magnesium for its absorption, and calcium works the best with vitamin D. Most of the brightly-colored fruits and vegetables are rich in nutrients. Here is a list of foods that can boost the immune system. Fruits: Apple, Guava, Papaya, Strawberries, Kiwi, Cantaloupe, Orange, Grapefruit, Pineapple, Grapes, Blueberries and red berries, Graviola, Pomegranate, Prunes, Plums, and Avocado. Vegetables: Bell peppers, Carrots, Spinach, Broccoli, Kale, Cabbage, Sweet potatoes, Cilantro, Onion, Garlic, Turnip Greens, Ginger, Mushrooms, Beets, Tomatoes, Asparagus, and Artichoke. Other Foods: Yogurt, Oats, Cereals, Nuts, Legumes, Flaxseed, Green tea, Seafood, Whole grains, Lean meats, like chicken and turkey, Tofu, Ginseng, Basil, Sage, Olive oil, Honey, Black pepper, Wheat germ, and Turmeric. This is one of the golden rules when it comes to healthy living. Stress hormones, like cortisone and adrenaline can suppress the immune system. According to studies conducted on rats, stressful conditions affect production of antibodies against viral infections. It was also suggested that rats subjected to mental stress had a shorter lifespan, when compared to rats subjected to physical stress. In short, it is concluded that stress can affect the immune system in a negative way. If possible, avoid situations that can be stressful for you. While exercising is good for beating stress, other activities, like yoga and medication may also prove effective. Even dancing and singing can beat stress to some extent. Spending time with your pet is an effective way of dealing with stress.

• Quit Smoking: This is one of the unhealthy habits that can cause damage to various bodily systems and organs. Even the immune system is not spared from the ill-effects of smoking. Smoking makes the immune system weak, and the body becomes prone to infections, like pneumonia. It also lowers the level of protective antioxidants in the blood.
• Get Sufficient Sleep: Deprivation of sleep has been linked to suppression of the immune system. It has been observed that people who don't get enough sleep are more prone to viral and bacterial infections. The ability of the immune system to produce antibodies against disease-causing microbes, also gets reduced. So try to get at least seven to eight hours of sleep daily.
• Increase Water Intake: Drinking lots of water is beneficial for the immune system in various ways. Water is needed for production of lymph, which in turn carries white blood cells and other such cells (produced by the immune system) throughout the body. It also helps in oxygenating blood, thereby enhancing the efficiency of body cells. Optimum intake of water is also linked to prevention of diseases, like arthritis.
• Avoid Junk Food: Refined and processed food products lack nutrients, and this will affect the immune system negatively. High level of fats in junk food is another cause of concern, as it suppresses this bodily system. The excess sugar hinders with the process of phagocytosis, through which the white blood cells destroy viruses and bacteria.

Another factor that can weaken the immune system is obesity. It is said that the excess fat cells in the body trigger chronic inflammation, thereby damaging healthy tissues. Animal studies have proved the fact that obesity reduces the rate of production of antibodies. So maintain a healthy body weight for a healthy immune system. In order to boost your immune system, you have to adopt a balanced diet, a healthy lifestyle, and maintain good hygiene. Apart from that, regular health check ups and medical screening tests will also prove beneficial.