Having a healthy immune system if vital to keeping yourself free from illness year round, and especially key during cold and flu season. The season lasts from October to March, and peak activity normally occurs in January and February. A special report by Harvard Health Publications says that the first step to protecting yourself and strengthening your immune system is adopting a healthy lifestyle. It goes on to list several factors, like maintaining a healthy weight, not smoking, controlling blood pressure, regular exercise, and adequate sleep.
Diet is important — and the report advises one rich in fruits, vegetables, and whole grains, but low in saturated fat. Speaking on diet more specifically, it says that although a trend has been noticed between malnutrition, and vulnerability to infectious diseases, causation has not been established. When certain nutrient deficiencies occur in animals, there is also an altered immune response. Some research has been done, but more is needed. The following are the eight nutrients that have the potential to be immune boosters and the foods where you can find them.
According to the National Institutes of Health, most people in the U.S. are not at risk for selenium deficiency. It is nutritionally essential in a person’s diet, containing more than two dozen selenoproteins, which are important for reproduction, DNA synthesis, thyroid hormone metabolism, and protection from oxidative damage and infection. The recommended intake of selenium is 55 micrograms. The foods that are highest in selenium are organ meats and seafood. Dairy, muscle meats, and cereals also tend to be good sources of the nutrient. Examples include tuna, halibut, brazil nuts, oatmeal, spinach, milk, and baked beans.
2. Vitamin A
This vitamin is composed of fat-soluble retinoids, like retinol, retinal, retinoic acid, and retinyl esters. A key aspect of vitamin A’s functions is its ability to maintain the normal function of organs like the lungs, kidneys, and heart. Adult men need about 900 micrograms, women 700. Vitamin A also regulates cell growth and associations between certain cancers and vitamin A has been observed. When proper levels of vitamin A are not present in a diet, researchers have noticed impaired immunity and a higher risk for infectious diseases. Vitamin A can be found in milk, eggs, and a variety of fruits and vegetables. Sweet potatoes, carrots, peppers, ricotta cheese, and pistachios are all good sources of vitamin A.
3. Vitamin B2
Also known as Riboflavin, this nutrient is important for keeping energy levels up. B2 doesn’t only keep you going, but it also will regulate the other B vitamins necessary for your health. There is a strong relationship between B1, and B2. When you reach proper amounts of B1 in your diet, it can help boost your B2 levels. It is important to keep this in balance with neither too much nor too little. Eating green beans, eggs, asparagus, and eggs are ways to incorporate vitamin B2 into your diet.
4. Vitamin B6
Vitamin B6 is the generic name given to six compounds. It preforms numerous functions in the body, including a healthy, functioning immune system. Adults need between 1.3 and 2 micrograms, depending on age, gender, and other factors. There have been several studies linking B6 deficiency to depressed immune response when a moderate dose was added, the immune functions were restored to proper levels. Foods containing vitamin B6 include bananas, cottage cheese, seedless raisins, and chickpeas.
5. Vitamin C
Although there is no solid support that vitamin C improves the immune system, even if it does not, it is possible the nutrient works in conjunction with others. The research does not indicate that it prevents a cold or the flu, but it may lessen the amount of time you are sick. It is important to regularly eat foods with vitamin C, because adding it after you are already ill does not appear to be beneficial. Vitamin C is necessary to form a protein that is used to make skin, ligaments, blood vessels, and tendons. It also has reparative functions for wounds, bones, and teeth. Most fruits and vegetables will have some amount of vitamin C, but cantaloupe, citruses, strawberries, tomatoes, and winter squash are all rich with the nutrient.
6. Vitamin D
Researchers are investigating whether the same properties that cause vitamin D respond to the bacterium that causes tuberculosis can also trigger a similar response with other diseases. Vitamin D is also known for its bone-health properties and ability to prevent osteoporosis. More groups are at risk for vitamin D deficiency than other nutrients on the list, including older adults and those with limited sun exposure.
Many people get their vitamin D from sunlight, and not many foods do not naturally contain vitamin D. Those that do are salmon, tuna, cheese, and egg yolks. Fortified milk is an important source of vitamin D for many in the U.S., and breakfast cereals will have the nutrient added as well.
7. Vitamin E
A number of fat-soluble compounds fall under the vitamin E umbrella. Three surveys have found that most Americans do not meet the daily requirements of vitamin E. Research indicates that when taken at proper levels, it may have anti-inflammatory and immune-enhancing properties. Studies show it is at least involved in immune function and metabolic processes. Nuts, seeds, and vegetable oils all contain vitamin E. Specifically, almonds, hazelnuts, sunflower oil, and mango are all sources.
When a person does not consume enough zinc, T cells, and other immune cells lose their ability to function as they should. Taking too much zinc also causes problems. In addition to immune system functions, zinc is important for protein synthesis, and would healing. There is no zinc storage system in the body, so it important to get the recommended intake daily. Men need 11 micrograms and women 8. Most Americans get zinc from meat and poultry, but it is also in cashews, yogurt, fortified breakfast cereals, kidney beans, peas, and cheese. Oysters are also incredibly high in zinc.