Our immune system is a complex interaction made up of at least six different cells, the bone marrow, lymph nodes, spleen, appendix and skin. The immune system has a vital role: to protect us from harmful substances, germs and cell changes that could make us ill. It’s also one of the most fundamental systems in the body that needs good care in order to prevent more serious and long-term conditions from creeping in.
As long as our immune system is running smoothly, we don’t notice that it’s there. But if it stops working properly illness follows. In order to do the best that we can to ensure its optimal function, we must provide it with good fuel, specifically certain nutrients from foods. These are vitamins A, C, D, E, B6 (pyridoxine), B9 (folate), B12 (cobalamin) and the minerals copper, iron, selenium and zinc.
Here we will talk about where to obtain these nutrients from and the quantity of foods to consume in order to ensure enough intake.
Vitamin A: important for T-cell activity (and also has a role in skin health). Good sources of vitamin A are eggs, dairy, dried fruits and orange/red fruits. A fresh mango will provide more than enough vitamin A for the day (roughly 1,800 IU)
Vitamin C: This popular vitamin is crucial for the function of our white blood cells (they help to fight harmful invaders), as well as maintain healthy skin. The recommended amount is 40mg per day; one medium red pepper will provide around 100mg. Because vitamin C is water-soluble, the body will use what it needs and safely excrete the rest.
Vitamin D: there is more and more compelling evidence in the relationship between vitamin D and lung health and protection from Covid-19. The minimum recommendation is at least 400iu per day. This vitamin is also vital for the health of bones, muscles and teeth. Ensure that your vitamin D is at an optimal level, not only by adequate and safe exposure to the sun, but also by consuming the relevant foods (eggs, dairy, oily fish, mushrooms) as well as supplementing with a bioavailable and synergistic kind. There is one that I personally use and recommend, so feel free to message me for information.
Vitamin E: this powerful antioxidant vitamin has a crucial effect on how our immune cells respond. It works in synergy with vitamin C to combat harmful free radicals. As it is fat-soluble, it is found in fatty foods, such as sunflower seeds; a handful contains well over half your daily recommended intake (4mg for men and 3mg for women).
B6: it helps the production of red blood cells and neurotransmitters. It is also linked with T-cell function and brain health. It is abundantly found in various types of food sources, such as meats and vegetables. For those who like to snack on nuts and seeds, a handful each of pistachios and sunflower seeds will provide half of your recommended intake of B6 (1.4mg and 1.2mg women).
Copper: another crucial trace element that helps to produce red and white blood cells. Organ meats, shiitake mushrooms and nuts and seeds are good sources. A handful of sesame seeds provide more than adult daily need of 1.2mg. A handful of cashews provides almost the whole requirement.
Iron: Iron is an essential mineral for both the first and secondary immune response. Seventy per cent of our iron is stored in our red blood cells and muscle cells. People who are deficient in iron are more prone to infections. Men need around 9mg and women around 15mg (aged 19-50). Dark green veg, legumes, pumpkin and sesame seeds are good sources of iron. To enhance absorption, combine foods with those containing vitamin C. A cup of cooked lentils will provide around 6.6mg of iron.
Zinc: this trace element can have a serious impact on the immune system if there is deficiency. In optimal levels, it can increase the numbers of T-cells and Natural Killer cells of the immune system. Men need 9.5mg and women 7mg. Good sources are nuts, seeds and pulses. Hemp seeds are a good source ( 3mg per handful).
Vit B12: this is the only B vitamin that is not present in plants. It helps keep the body’s nerve and blood cells healthy and helps make DNA. It is crucial in preventing megaloblastic anaemia. Good sources of vitamin B12 are meat, eggs, dairy and fortified foods. Baker’s yeast is an excellent source of vitamin B12; a 5g serving will deliver 2.2mcg, which is more than the recommended daily amount (1.5mcg). Yeast is also a great source of other B vitamins, as well as immune-boosting zinc, selenium, iron and copper.
Folate (B9): known as folic acid in its manufactured form, this is the vitamin that is crucial in preventing spina bifida in the unborn babies. It is also thought to play a role in the development of immune cells. An adult needs 400mcg and the best plant-based source is lentils (100g cooked lentils will provide nearly half of the amount needed). Other good sources are beans, asparagus, eggs and leafy greens.
Selenium is a strong anti-oxidant and is vital for the immune system in helping to reduce infection. It also helps with reproduction, thyroid hormone metabolism and DNA synthesis. Just two brazil nuts a day will provide the recommended amount of 55mcg for the average adult. Other sources are meat, fish, eggs and nuts.
Here is a sample meal plan one can have to ensure the above nutrients are present in the right amounts for a strong immune system. Remember that the body works together as a whole, so if the immune system’s needs are fulfilled, this will help it to function optimally in order to help the other systems also work at their best.
Lunch or dinner could be a lentil dish with mushrooms (add onions, garlic, peppers, spinach for extra nutrition), sprinkled with a few flakes of baker’s yeast for extra taste.
Snacks could be a couple of handfuls of mixed nuts and seeds, such as pistachios, cashews, brazil nuts, sunflower and sesame seeds. Ensure you get out in the sunshine (when it’s out! We live in England after all), to boost your body with some vitamin D production. Breakfast could be wholemeal toast (B vitamins) with some slices of avocado (omega 3 fatty acids) and a little drizzle of olive oil (omega 3 fatty acids) and lemon (vitamin C).
If you eat meat, a good quality, organic and free-range steak of venison (iron) accompanied by a raw mixed salad (zinc, copper, etc) and baked asparagus (folate) and sweet potato (vitamin A). Peppercorn sauce is a good option and a few hemp seeds can be incorporated in there for extra iron.
The important matter is to ‘play’ around with foods every day to enhance the synergy of nutrients between them. Once we understand how nutrients work with each other, we have a better chance of getting the correct combination to ensure optimal function of not just our immune system, but all other systems too. Happy play!