Our immune system is made up of two separate responses: the innate (or natural) immune response and the adaptive immune response. The innate immune response is our oldest evolutionarily inherited system, and it consists of the first line of defence (with physical barriers such as the skin, mucous membranes and antimicrobial peptides) and the second line of defence (with natural killer cells, inflammation and the complement system). The adaptive immune response is the system we acquire throughout life when faced by various pathogens. It is a highly specialized system that allows the body to recognize a large variety of antigens and to create an immunological memory, leading to future protection against the same pathogen. The adaptive system can be divided up into humoral immunity (consisting of B cells) and cell-mediated immunity (consisting of T cells).
The strength of our immune response is dependent on genetic factors as well as environmental factors, such as what we eat, how much we exercise, the quality of our sleep and how much stress we have in our lives. The impact of various lifestyle factors and the need to adjust some of them can vary between individuals due to biochemical differences. Some of these biochemical differences can be identified using a DNA test. In this article we will go through some of the areas that can impact the immune response, from a genetic perspective. These areas are oxidative stress, inflammation, food responsiveness and vitamin metabolism.
Oxidative stress is a result of too many free radicals (highly reactive molecules) in the body and not enough antioxidants to neutralise them. Research has shown that certain gene variants have been associated with a poorer antioxidant status and increased oxidative stress. Long-term increased oxidative stress can lead to damages of the DNA, proteins and cell membranes as well as low-grade chronic inflammation. Inflammation in itself is not a bad thing, since it is an important part of the immune response and essential for tissue healing. However, when it becomes chronic, it can lead to a range of different diseases. For individuals carrying genetic variants that predisposes to increased oxidative stress or increased levels of certain pro-inflammatory cytokines, it is important to incorporate an anti-inflammatory diet low in saturated fats and high in omega 3, such as the Mediterranean diet. Moreover, supplements such as ginger, curcumin and trans-resveratrol (from red berries) have been shown to have a beneficial effect in supporting a normal immune response.
The food we eat can greatly impact the function and strength of our immune system. Food can serve both as a strengthening as well as a weakening factor, depending on its nutritive content and how the body responds to it. Certain food components, such as gluten, can trigger an immune reaction in some individuals. However, not many are aware of the fact that gluten can have an immunoreactive effect even for those that are not coeliac. For people that are gluten sensitive and not aware of it, consuming gluten can actually cause a state of low-grade chronic inflammation in the gut, with IBS-like symptoms as a result. By testing for certain gene variants within food responsiveness you can find out if you are one of those who would feel better by avoiding gluten. Another important area that can have a major effect on the immune system is that of vitamin metabolism. Our immune system is dependent on certain vitamins and minerals to function properly. Therefore, it is crucial to make sure sufficient intake. Yet, some individuals might risk nutritional deficiencies even when their diet is varied and covers the levels needed for adequate intake. Research has shown that some genetic variants could lead to poorer uptake and metabolisation of certain crucial vitamins, such as B12, folate, vitamin A, D and C. If that is the case, supplementation will be necessary.