Every day you are exposed to potential, mostly invisible threats. To counter this relentless attack, your body has developed a complex way to protect you - your immune system.

Many people never think about their immune system. However, it's a good idea to be more active in supporting your immune system health, especially as you get older.

What does your immune system consist of?
The immune system is actually a vast network of organs, tissues, and cells that work together to support health.

Your defense system allows your body to recognize what is foreign and what is “self.” The immune system uses unique methods to support your health.

In general, there are two subsystems of your immune system - the innate immune system and the adaptive immune system.

The innate immune system provides a rapid defense against potential problems, but works non-specifically. And although it is the dominant system for defense, it does not provide lasting immunity.

However, it provides specific barriers to optimal immune function.

For example, your skin acts as a mechanical barrier. Tears and urine, coughing and sneezing, and the mucus in your intestines and respiratory tract support your immune system.

Chemical barriers also help. Enzymes in tears and saliva as well as acids and enzymes in the stomach also serve to promote a healthy immune response and ward off harmful pathogens.

An example of a biological barrier is the beneficial probiotic bacteria in your gut, bacteria that should ideally be in the majority and competing with unfriendly bacteria.

There are several different types of specialized innate immune cells. White blood cells called neutrophils are the most numerous innate immune cells.

Innate cells respond quickly and comprehensively to potential problems and initiate the second type of immune response, called acquired (adaptive) immunity.

In contrast to innate responses, adaptive immune responses provide long-lasting effects. White blood cells, the B and T lymphocytes, are involved in the adaptive immune response.

Where is your immune system located?

Your immune system is spread throughout your body.

• The skin . As you've seen, your skin is your first line of defense.
• Bone marrow. The bone marrow houses stem cells that can develop into different cell types. A stem cell from the bone marrow is a precursor to innate immune cells. The adaptive immune cells - the B cells and T cells - arise from another stem cell.
• Thymus. This tiny organ is located in the upper chest in front of the heart. T cells mature in the thymus. However, as we age, the function of the thymus declines.
• Lymphatic system . This system contains a network of vessels that carry a clear fluid called lymph, as well as tissues called lymph nodes. The lymphatic system transports immune cells to approximately 600 lymph nodes located throughout the body. The lymph nodes contain white blood cells, particularly lymphocytes, which support immune system health.
• mucosal tissue. Since mucosal surfaces are potential portals of entry, special immune nodes are located in mucosal tissues such as the gastrointestinal tract and the respiratory tract. The gut contains 70% of the body's immune cells and produces the majority of antibodies.
• Spleen. This organ is located on the left side of the body behind the stomach. It contains many B lymphocytes that support the immune response.

Factors affecting immune system health

In older adults, immune cell response and antibody production may change. An older person's bone marrow can no longer produce as many stem cells that develop into immune cells.

Older people tend to suffer more from an unbalanced inflammatory response.

Nutritional issues also influence the well-being of the immune system. Older people tend to eat less food and have less variety in their diet, so their vitamin consumption may not be optimal. Research shows that vitamins and minerals support immune system function.

Mental health also affects the immune system at any age. Mood swings and excessive stress can affect immune function.

How to improve immune system function

Because the aging process and other factors affect immune function, it is important to know how to support immune system health. Here are some simple strategies:

• Avoid smoking and minimize alcohol consumption . Tobacco smoking and excessive alcohol consumption can affect immune system function.
• Stay active and maintain your optimal weight . Exercise supports antibody production and immune cell health and promotes healthy levels of stress hormones. When it comes to weight, recent Australian research has found that even modest weight loss can boost immune system health.
• Manage your stress levels and emotional health. While short-term stress can promote immune system well-being, long-term stress cannot. Research shows that immune cell activity is reduced in mood problems and social isolation. Therefore, it is important to engage in social relationships, learn stress-reducing techniques, and seek professional help for emotional problems.
• Get enough sleep . Good sleep promotes the immune response. Most health experts recommend 7 to 9 hours of good quality sleep per night for adults of all ages. Prolonged lack of sleep can lead to unbalanced inflammatory responses.
• Pay attention to diet and supplementary nutrients. For optimal immune health, it's good to stock up on foods rich in phytonutrients and antioxidants: dark green leafy vegetables, tomatoes, peppers, broccoli, berries, and other colorful fruits. Foods to avoid for better immune system health include all processed foods, sugar, trans fats, refined vegetable oils, and white flour. Certain nutrients have been shown to boost immunity. Supplements containing omega-3 fatty acids, found in fatty fish or marine oil, support immune function. Probiotic supplements support the population of “friendly” intestinal bacteria for optimal mucous membrane immunity. Other plant nutrients, vitamins like vitamins C and D3, and minerals like zinc also help support immune system health.