An important line of defense for the immune system is the lymphatic system, which consists of approximately 500-600 lymph nodes, that produce and store cells that fight infection and disease. Regular movement plays a significant role in its being able to function correctly. The lymphatic system relies on breathing, movement, and the contraction of muscles to circulate lymph and return it to our cardiovascular system. Poor lymph circulation can lead to inflammation. Regular exercise, even walking, can promote the flow of lymph allowing cells and substances in the immune system to move throughout the body.
In addition to movement, staying well-hydrated helps optimize the lymphatic system since it is 96% water. Dehydration can hinder efficient flow. It is essential to drink plenty of fluids throughout the cold and flu season to ensure adequate hydration and proper lymphatic system function. Rehydrating properly is especially crucial for those who regularly exercise. To completely rehydrate, I recommend drinking 1 1/2 times the weight lost in sweat from exercise. Someone who loses 16 oz of fluids during an exercise session, for example, should consume about 24 oz of liquid during recovery.
Did you know that approximately 70% of the immune system resides in the gut? Gut bacteria help produce the immune system’s T cells, which are one of two primary white blood cells. We know that the food we eat has a direct impact on the population of bacteria in the gut and the overall health of our gut, so inadvertently eating for a healthy gut supports a healthy immune system. Many factors influence gut health, and when it comes to diet, high plant diversity is the number one influencer. Plant diversity means different types of nuts, seeds, non-starchy and starchy vegetables, fruits, legumes, and whole grains. Think wide variety and high quantity. Fiber and pre-biotics are what primarily feed healthy bacteria, so by eating a variety of fiber types, we can ensure we have a variety of beneficial bacteria to help protect us through the substances they produce.
In addition to including a variety of plant foods, including these nutrients, plays an integral role in immune system function:
- Vitamin C – this vitamin contributes to immune defense by supporting cellular functions of the immune system. Vitamin C also promotes the production of B and T cells of the immune system. Infection can increase our needs of vitamin C, and deficiency can hinder immune defense. Because this vitamin is water-soluble, we need a daily intake of vitamin C rich foods. Citrus fruits are rich sources. These include grapefruits, oranges, tangerines, lemons, and limes. Peppers of all color varieties are good sources as are kiwis, strawberries, kale, and broccoli. Vitamin C isfound exclusively in plant foods, and almost every fruit and vegetable have at least some quantity. So, to optimize intake, include fruits and vegetables with every meal and include several sources of vitamin C rich foods throughout the day.
- Vitamin B6 – this vitamin is another water-soluble vitamin that needs to be consumed daily. It plays a role in supporting biochemical reactions of the immune system. B6 rich foods include green vegetables, sweet potatoes, avocados, bananas, and chickpeas.
- Vitamin E – this vitamin works as an antioxidant helping to protect the body. Vitamin E is fat-soluble and so it is best absorbed with a little fat. Luckily many of the foods rich in vitamin E also provide some fat. Good sources are hazelnuts, sunflower seeds, almonds, peanuts, and spinach.
My philosophy is that a food first approach is best. Fruits and vegetables, for example, are packaged together in such a way that the body can get what it needs. When we consume an orange, we are getting so much more than just vitamin C. We are getting fiber, which feeds the healthy gut bacteria playing a role in our immunity. We are getting phytonutrients that are partly attached to the fiber and are not found in pill forms. We are getting large amounts of water that help with hydration. We are getting energy for the cells in the form of carbohydrates. We are also getting additional vitamins and minerals. With supplementation, on the other hand, it is far too easy to take in more than what is needed. For example, it is difficult to eat an entire bag of oranges, but quite easy to take in too many vitamin chews or powders. This caution is even more prevalent in fat soluble vitamins such as E, where more is not necessarily better. If too much Vitamin E is consumed, it can have the opposite effect. It is difficult to take in too much vitamin E from food alone.
In summary- To support a healthy immune system, I recommend the following basics.
- Choose a food-first diet rather than supplements
- Include a variety of plant foods of varying colors with every meal
- Stay hydrated, especially when exercising
- Remember regular movement and exercise to support lymph flow and function.