Does the immune-boosting diet even exist? It is important to understand some basic information before digging into how diet influences the immune system. The immune system is composed of both the innate immune system, defenses people are born with and the adaptive immune system, defenses that are developed after exposure to "germs" (aka microbes).1 Nutrients from various foods play an essential role in the development of the immune system but overall, adequate nutrition is necessary for all cells of the body to perform their various tasks.2
The One's Hard at Work
Vitamin A
Vitamin A is most known to support eye function, but it also plays a vital role in helping the immune responses.3 There are different forms of Vitamin A, but overall, it is important to know that it can be found in the skin and cells of mucous that line the airways, digestive tract and urinary tract. This means that these various barriers made of Vitamin As and other materials are often the first line of defense against unknown germs. Dietary sources of Vitamin A include, but are not limited to, cod liver oil, sweet potato, pumpkin, carrots, cantaloupe, butternut squash and spinach.
Vitamin D
When we think of vitamin D, we think of sunshine. The active form of vitamin D in the body, the form that does the work, is vitamin D3. Adequate intake can prevent the body from viral infections. It plays a role in the creation of proteins that make up the barriers in between and around cells so they can protect from infections. Vitamin D3 is not found naturally in a lot of foods but 10-30 minutes of sunlight at midday can allow for it to be created from what is already present in the body. Dietary sources include pink salmon, mackerel, tuna, dairy products fortified with vitamin D, fortified cereal, and orange juice fortified with vitamin D.
Vitamin C
Vitamin C is often the first thought people have when they think about immune support. It is an antioxidant, so it has the power to reduce the harmful molecules in the body by offering parts of itself. It also works to stimulate the efficiency of white blood cells, which are a part of the immune system. Sources of vitamin C in foods include kiwifruit, grapefruit juice, orange juice, red bell peppers, strawberries, oranges, broccoli and most fruits and vegetables.
Vitamin E
The active form of the vitamin works only slightly differently than vitamin C in the way that it also gives part of itself in order to neutralize the harmful molecules in the body. Sources of vitamin E include meats such as salmon and beef; vegetables such as spinach, broccoli, and tomatoes; nuts and seeds such as sunflower seed kernels, almonds, hazelnuts, and peanuts; and vegetable oils.
Selenium
Selenium is one of the many antioxidants that give part itself up in order to protect the body from harmful molecules. Sources include brazil nuts, garlic, onion, broccoli, wheat, soy, clams, and tuna.
Fatty Acids
Fatty acids are different than vitamins and minerals because they are included under the macronutrient category of fats rather than being considered a micronutrient. Three fatty acids connected to a glycerol backbone make a triglyceride, the storage form of fat. Diet-derived fatty acids are a component of the layer on the outside of the cell[SO1] .4 This layer protects the cell from harmful molecules entering. Sources include vegetable oils, seeds, nuts, and fish oils.
The Team Players
Iron
Iron is a team player when it comes to the immune system. It helps to regulate the T-cells, which are immune cells.3 It is involved in the reactions in which other vitamins and minerals give themselves up to decrease the number of harmful molecules in the body. Heme sources of iron include those that are derived from animals and non-heme sources include those that are derived from plants. Heme sources of iron are easier for the body to absorb and use for functioning. Vegetarians and vegans only consume non-heme sources of iron. Heme sources are beef, chicken, liver, oysters, clams, tuna, mussels, and pork. Non-heme sources are fortified cereals, enriched bread, beans, lentils, nuts and seeds.
Zinc
Zinc helps antioxidants neutralize harmful molecules in the body, much like iron. Sources of zinc include oysters, crab, beef, fortified whole grains, turkey, soybeans, chickpeas, and black beans.
Copper
Copper assists other antioxidants in eliminating harmful molecules in the body. Sources of copper include beef liver, cashew nuts, sunflower seed kernels, firm tofu, chickpeas, and dark chocolate.
Amino Acids
Amino acids are the building blocks of proteins and also assist in the reactions that allow for vitamins and minerals to protect the body. Specific amino acids are involved in the regulation of the immune response. It is important to try to consume the 9 essential amino acids. Sources of all 9 include beef, poultry, fish, eggs, soy, quinoa, and buckwheat.
The biggest takeaway from this article should be that a balanced diet, with a variety of all 5 food groups, has the ability to support the immune system. If more guidance is needed when looking to modify the diet, reaching out to a dietitian is an option. The Dietary Guidelines for Americans 2020-2025 provide numerous resources on achieving a well-rounded diet and a link will be posted below for exploring!5 Always consult a doctor or registered dietitian before taking over-the-counter supplements.
References
1. Johns Hopkins Medicine. The Immune System. https://www.hopkinsmedicine.org/health/conditions-and-diseases/the-immu…. Published January 5, 2022. Accessed March 1, 2023.
2. Noor S, Piscopo S, Gasmi A. Nutrients Interaction with the Immune System. Arch Razi Inst. 2021 Dec 30;76(6):1579-1588. doi: 10.22092/ari.2021.356098.1775. PMID: 35546980; PMCID: PMC9083862.
3. Vitamins. Linus Pauling Institute. https://lpi.oregonstate.edu/mic/vitamins. Published October 5, 2016. Accessed March 1, 2023.
4. de Carvalho CCCR, Caramujo MJ. The Various Roles of Fatty Acids. Molecules. 2018 Oct 9;23(10):2583. doi: 10.3390/molecules23102583. PMID: 30304860; PMCID: PMC6222795.
5. Dietary guidelines for Americans 2020-2025. https://www.dietaryguidelines.gov/. Published 2020. Accessed March 1, 2023.
Check Out Our New Health & Well-Being Page
Our specialists help create healthy people and healthy places in New Hampshire.
