When transitioning through summer and winter- our immune system is usually weakened, and our body finds it harder to meet the challenges of the new season. The sharp changes in the weather that we all experience further stresses our bodies. Apart from feeling more and more exhausted, tired and sluggish, we are more likely to get a cold, flu or parainfluenza than at any other time of the year. Therefore, it is vital to take care of ourselves and strengthen our immunity during spring/autumn.
Vitamins and minerals – why are they so important and how to ensure we are getting enough of them?
In general, the best option to get vitamins and minerals for proper immune functioning is through a balanced and varied diet. For more vitamin C- rely on citrus fruits and rose hips. The optimal thing to do is to eat seasonal fruits and vegetables that are packed with vitamins, minerals and antioxidants.
The role of fats – why are they a key element in nutrition regimes?
Immunity-important micronutrients are the fat-soluble vitamins A and E, which have a strong anti-inflammatory and antioxidant effect. They are seen in carrots, sweet potatoes, milk, butter, liver, some nuts and seeds and avocados.
Vitamin D is also fat-soluble, and it has gained a lot of popularity lately since it proposes tremendous benefits in terms of our immune functions. Despite its name, it is not a vitamin, but a steroid hormone that can affect about 2,000 genes in the human body. It produces over 200 antimicrobial peptides such as cathelicidin, which is a naturally occurring broad-spectrum antibiotic. This is one of the reasons why vitamin D is so effective against colds and the flu.
The protective mechanisms of the immune system are affected by energy intake and nutrientintake as well. High-calorie consumption is associated with impaired lymphocyte (protective cells of the immune system) response. Moreover, increased dietary intake of fats suppresses the functions of other vital immune cells- T cells and natural “killer” cells. Numerous studies suggest that the capacity of “killer” immune cells is increased when fat intake is reduced from 32% to 22% of daily energy intake. In addition to the amount of fat in the diet- it is important to address the importance of the type of fat that is consumed.. Fish oils, for example, are rich in long-chain omega-3 fatty acids, which are anti-inflammatory and suppress the release of cytokines and reduce their inflammatory action. Fats from nuts can also contain omega-3 fatty acids, mainly alpha-linolenic acids which is not a long-chain fatty acid, but it has the potential to help with the production of long-chain omega-3s in the body. It is advisable to avoid the overconsumption of sugar and sugar-rich foods since they also elevate cytokine production in the body.
The role of antioxidants
Leukocytes release free radicals in response to their interaction with an infectious agent. When they accumulate in the body, they cause the so-called “oxidative stress” which damages normal cells. Therefore, it is important to maintain an adequate antioxidant status in the body. Fruits and vegetables are rich in substances with antioxidant properties, especially those with bright and saturated colours- “traffic light colours”: vitamin C, carotenes, bioflavonoids. Green and black tea are also wonderful sources of bioflavonoids. Some minerals such as zinc, selenium, manganese serve as cofactors of enzymes that help with the proper functioning of the antioxidant system in our bodies. These minerals are contained in wholegrains, legumes and meat.
The role of proteins
Additionally, to improve our immune status, it is extremely important to consume an adequate amount of protein. Proteins are necessary for the synthesis of immunoactive molecules and receptor. Thus, they should be present in sufficient quantities in our daily diet. Vegetarians also have the potential to maintain a protein-rich diet if it is well-formulated. Animal Proteins have plant alternatives such as legumes: chickpea, lentils, soy. Other plants also contain protein: some vegetables like i.e.. broccoli, cereals, and nuts. Monodiets, the ones excluding whole groups of nutrients, shouldn’t be applied for a long time because it impairs the body’s immune function.
Immunity and gut health – how are they related?
A number of studies have documented the importance of our intestinal health in relation of the strength of the immune system. The microbiome is influenced by many factors and contributes greatly to our health status on so many levels. According to a study published in the Immunology Journal in May 2009, the complex effects of the bacteria in our body supports proper development of our defense mechanisms. Among these mechanisms is the intestinal lymphoid tissue. For example. Payer’s patches is a type of lymphoid tissue and it monitors the entry of pathogenic bacteria into the gut. When pathogens are detected, an immune response in the mucosa is generated and the immune system is activated with the help of macrophages, dendrites, B-lymphocytes and T-lymphocytes. However, gastrointestinal issues can lead to various imbalances such as vitamin, water or chemical imbalances that directly affect the health and efficiency of the intestinal lymphoid tissues. That’s why, it is extremely important to consume probiotic foods such as fermented dairy products- yogurt, kefir,. They contain bifidobacterial which can break down toxins and help in maintaining proper immune function. Moreover, they contain vitamins A, B, D and E which are essential for human health. There are many mechanisms in our intestines that contribute to the production of serotonin- the happiness hormone. On the other hand, fermented milk products contain the amino acid- tryptophan, which helps with serotonin production in the gut. Therefore, a healthy intestinal microflora can support good health.
In conclusion, balanced and varied diet rich in vitamins, minerals, antioxidants, proteins, good fats, fiber and probiotic foods is a key factor in healthy immune system. Adequate sleep, hydration and regular physical activity are no less important for our health. Do not underestimate these factors because they are as important as nutrition. Try to consume seasonal foods daily, probiotics, lean meats, more fish, wholegrains and at least 1.5-2L water every day. Moreover, do not forget to address your thoughts and emotions. Positively charge yourself by smiling more. Be happy and enjoy life as it is!
Authors: Rayna Stoyanova, MD, and Kristina Vavura