What is the Immune System
The immune system is a complex organ system in the body comprised of white blood cells, skin, mucus, and bacteria. Its central role is to seek, recruit, attack, and destroy foreign invaders, such as bacteria and viruses that enter the body. There are two main levels of immunity.
1. Innate immunity system
The first level is called the innate immune system. This system provides a quick first line of defense and acts against a wide range of pathogens. The innate immunity system refers to nonspecific defense mechanisms that come into play immediately or within hours of an antigen's appearance in the body. These mechanisms include physical barriers such as skin, chemicals in the blood, and immune system cells that attack foreign cells in the body. The chemical properties of the antigen activate the innate immune response.
2. Adaptive Immune System
The second main level of immunity is called the adaptive immune system. This level refers to antigen-specific immune response. The adaptive immune response is more complicated than innate. The antigen first must be processed and recognized. Once an antigen is identified, the adaptive immune system creates an army of immune cells specifically designed to attack that antigen.
Adaptive immunity also includes a "memory" that makes future responses against a specific antigen more efficient.
Keywords explained:
Antigen - Anything that causes an immune response is called an antigen. An antigen may be harmless, such as grass pollen, or harmful, such as the flu virus.
Pathogen - Disease-causing antigens are called pathogens. The immune system is designed to protect the body from pathogens.
How to Support Your Immune System
The immune system is precisely that — a system, not a single entity. For it to function well, it requires balance and harmony. Researchers are still exploring the effects of diet, exercise, age, psychological stress, and other factors on the immune response.
In general, a healthy lifestyle is the single best step you can take toward naturally keeping your immune system strong and healthy. Every system in your body, including the immune system, functions better when following balanced and healthy strategies such as these:
• Eating a whole food diet with plenty of fruit and veg
• Exercising regularly
• Staying hydrated
• Maintaining a healthy weight
• Getting enough sleep
• Reducing stress
• Drinking alcohol in moderation
• Not smoking
Diet & Your Immune System
There is some evidence that various micronutrient deficiencies (think vitamins and minerals) could alter immune responses. However, the impact of these immune system changes on health is less clear, and the effects are yet to be assessed.
So, if you suspect you may have micronutrient deficiencies, make sure you eat a varied diet with ample amounts of fruit and vegetables or support yourself with a good quality multivitamin.
(Read the information below to find out which are the best immunity boosting fruit and vegetables and how to incorporate them in your diet.)
Vitamins, Minerals & Antioxidants for Your Immune System
Vitamin D:
Research shows that vitamin D supplementation may reduce the risk for viral infections, including respiratory tract infections, by reducing the production of pro-inflammatory compounds in the body.
Supplementation:
The body produces vitamin D from cholesterol, provided there is an adequate amount of UV light from sun exposure.
For moderate supplementation, a 1,000-2,000IU dose of vitamin D3 is sufficient to meet the needs of most of the population. The safe upper limit in the United States and Canada is 4,000IU/day.
Vitamins C and E:
Vitamins C and E are antioxidants that help to destroy free radicals and support the body's natural immune response.
Vitamin C Sources:
• red bell peppers
• oranges
• strawberries
• broccoli
• lemons
Vitamin E sources:
• almonds
• spinach
• avocado
• olives
Vitamin C Supplementation:
Vitamin C is often supplemented to reduce the symptoms of the common cold. Supplementing vitamin C can reduce the duration of a cold by 8-14% in any population, when it is taken as a daily preventative measure, or at the beginning of a cold.
The Recommended Daily Intake (RDI) of vitamin C is 100-200mg. This is easily attained through the diet, so supplementation of such low doses is usually unnecessary. Higher doses of vitamin C, up to 2,000mg, are used to support the immune system (for athletes) or reduce the duration of the common cold.
Vitamin E Supplementation:
Maintaining adequate levels of vitamin E in the body can be achieved through very low daily doses of 15mg (22.4 IU) or less. This dose of vitamin E can be acquired through the diet, making supplementation unnecessary in many cases. An older person supplementing vitamin E to improve immunity should take a 50-200mg dose.
Beta-Carotene:
Beta-carotene is a powerful antioxidant that can reduce inflammation and boost immune function by increasing disease-fighting cells in the body.
Sources:
• sweet potatoes
• carrots
• green leafy vegetables
Zinc:
Zinc is a mineral that can help boost white blood cells, which defend against invaders.
Sources:
• pumpkin seeds
• sesame seeds
• beans
• lentils
Supplementation:
Zinc has two standard dosages. The low dosage is 5-10mg, while the high dosage is 25-45mg. The low dose works well as a daily preventative, while the high dosage should be taken by anyone at risk for a zinc deficiency.
Allicin:
Allicin is the principal bioactive compound present in the aqueous extract of garlic. When garlic is chopped or crushed, the alliinase enzyme is activated, and allicin is produced. When cooking with garlic, it is recommended to crush or chop it and leave for 10 mins for the enzyme to be activated.
The benefits of garlic to health have been proclaimed for centuries; however, only recently, it's been proposed as a promising candidate for maintaining a healthy immune system.
Most studies on garlic use a dosage range of 600-1,200mg a day, usually divided into multiple doses. The minimum effective dose for raw garlic is a single segment of a garlic bulb (called a clove), eaten with meals two or three times a day.
Astragalus:
Astragalus membranaceus is an important herb in traditional Chinese medicine. It has been used in a wide variety of herbal blends and 'natural' remedies. This Chinese herb has been researched for its cardioprotective, anti-inflammatory, and longevity effects.
Supplementation:
Astragalus membranaceus and Angelicae Sinensis are highly synergistic, meaning they are more powerful when taken together. This combination is traditionally called Dang-gui buxue tang.
The starting point for the preparation of Dang-gui buxue tang in traditional Chinese medicine is 30g of Astragalus membranaceus root paired with 6g of Angelicae Sinensis. This is a 5:1 ratio, which is ideal for extracting the bioactive ingredients of the plants.
The main bioactive compound in Astragalus membranaceus is astragaloside IV, which can be supplemented by its self. The standard dose for astragaloside IV is 5-10mg.