Immune System and Nutrition: New Insights from Research

Boosting the immune system - but how?

The good news right away: A strong immune system is able to defend itself against many intruders. If everything runs optimally, our defense ensures that troublemakers do not even enter the body and cannot multiply. However, poor sleep, stress, medication intake, but above all an unhealthy diet and an unbalanced micronutrient balance can weaken our immune system.

Micronutrients that support the immune system

For decades, we believed that only Vitamin C and Zinc were THE solution for a strong immune system. This has been disproven. Among the vitamins and trace elements that support the immune system are not only vitamin C and zinc, but also vitamin A, vitamin D, folic acid, vitamin B6, vitamin B12, iron, selenium, and copper. The processes in the immune system are complex. Therefore, a broad base of vitamins and trace elements is important. Isolated nutrients can lead to imbalances and furthermore, vitamins and trace elements support and complement each other - like small wheels in a finely tuned clockwork.

Important: Only if you eat a varied diet consistently and are well supplied with all necessary micronutrients, your immune system has the best possible conditions to defend itself against intruders.

Eating to strengthen the immune system - here's how to do it

For an immune-boosting diet, naturalness and variety are particularly important - these are important findings of current nutritional research. Researchers from Bonn examined how a typical German average diet affects our immune system: The combination of many unhealthy fats, lots of sugar, few fibers, and generally few micronutrient-rich foods "confuses" our immune system and leads to inflammatory reactions similar to a bacterial infection¹ - not to mention that it does not provide our immune system with the micronutrients it needs. The problem is: if our defense is constantly busy with inflammation, there are no free capacities for other tasks.

Because our overall health also influences how well our immune system deals with intruders. It has long been known that conditions such as obesity, cardiovascular diseases, etc. weaken our defenses. Dr. Fiona Godlee, physician and editor-in-chief of the renowned British Medical Journal, therefore points out in an editorial the importance of a healthy diet²: Fruits, vegetables, whole grains, and legumes should be consumed more, while processed foods and meat should be minimized.

Another recent study confirms the dramatic consequences of malnutrition for our immune system: A diet high in salt (corresponding to the typical average diet) also significantly affects the immune response. Excessive salt consumption made infections more severe and weakened certain immune cells³. On a low-salt diet, the immune cells were significantly better at dealing with intruders and fewer germs could be detected. The World Health Organization (WHO) also recommends limiting daily salt intake to a maximum of five grams. However, in Germany, on average, we consume more: women consume about 8 grams, men 10 grams per day.

Strengthening the defense smartly & optimally

Choosing the right decisions for our diet daily benefits our immune system. Our tips:

• Professional societies recommend consuming at least five portions of fruits and vegetables per day. They not only provide us with micronutrients, but also with secondary plant substances. For example, beta-carotene, which is converted into vitamin A in the body, can be found in red, yellow, and orange-colored vegetables and fruits such as pumpkin, oranges, and carrots. Vitamin A supports healthy mucous membranes, the first important defense barrier of our immune system. If the defense is already able to repel intruders here, they don't even have the chance to multiply in the body.

• A part of the consumed fruits and vegetables should be eaten raw as salad or raw vegetables. Many vitamins are sensitive to heat. Therefore, uncooked fresh food is an important source of vitamins for us.

• Broad base of micronutrients: Do not reduce your immune system to just Vitamin C and Zinc. Immune cells "work" more complexly than many think and rely on all ten of the total immune-supporting micronutrients. Almost every step requires micronutrients, which also complement each other. Therefore, pay attention to a broad base of micronutrients and raise your micronutrient levels as broadly as possible to avoid imbalances.

• No single food provides all the necessary micronutrients. Nutrition experts recommend eating 25 different types of vegetables and fruits per week in order to benefit from as many important nutrients as possible. So-called superfoods are a good addition from time to time - but a diverse diet is the basis for strong immune defenses.

• Cooked vegetable dishes warm you up from the inside, which is beneficial during the cold season. Now is the time to use regional vegetables such as celery, Brussels sprouts, beetroot, all types of pumpkin, broccoli and pointed cabbage, which are still rich in micronutrients thanks to short transport routes and storage times. With peppers, tomatoes, and other produce that travel long distances, there is often not much left in terms of vitamins. Try to also pay attention to organic farming. Studies show that organic vegetables contain more secondary plant substances.

• Enhance your dishes cleverly with valuable onions, garlic, and ginger. The pungent substances in them are considered to be antibacterial.

• Instead of seasoning with salt, it is better to use fresh herbs, as too much salt weakens the immune system. Even in small quantities, they enrich our diet with valuable vitamins and trace elements.

• Dietary fibers serve, among other things, as food for our good gut bacteria. As most immune cells are located in the gut, a healthy gut flora determines our immune system. Eat a source of fiber with every meal, such as whole grain products like whole grain bread, buckwheat, lentils, beans, barley, whole grain couscous, or oatmeal. Vegetables also provide fiber. Cabbage, carrots, and chicory are particularly rich in fiber. Resistant starch, which forms when potatoes and pasta are cooled, is also a good source of fiber, as are flaxseeds, nuts, and seeds.

• Iron-rich foods: According to the National Consumption Study II, women in particular should make sure to eat enough iron-rich foods. Iron also supports the immune system. In addition to nuts, seeds, legumes, and whole grains, iron can also be found in peas, cabbage, spinach, and black salsify. If we eat something rich in vitamin C such as vegetables, herbs, or fruit with it, this increases the absorption of iron - this is just one example of how micronutrients are needed and complement each other. However, coffee and black tea should be avoided during and shortly after meals, as they inhibit iron absorption.

• Vitamin D: During the sunless season, our body is not able to produce vitamin D (which is actually a hormone) in the skin. Our vitamin D levels drop to their lowest point. Since vitamin D is involved in immune function, we should pay attention to good sources of vitamin D in our diet, especially during this time. Read this article to find out how you can get your vitamin D even in winter.

• Green leafy vegetables, nuts, and whole grains provide us with vitamin B6 and folic acid - two still rather unknown, and therefore unjustly underestimated vitamins for our immune system.

• Better to leave out: You should minimize sugar, convenience food, and salt. It's best to reduce animal products and pay attention to the best quality and origin. A recent study once again showed how replacing animal proteins with plant-based proteins can reduce our mortality rate⁴. It has also been proven that alcohol and nicotine weaken the immune system.

For our immune system, it is important to eat a varied, natural, and not too one-sided diet. This way, we have a good chance of getting through this autumn and winter with the best possible conditions. In addition, a healthy diet can also help prevent other risk factors such as diabetes and cardiovascular diseases. So, opt for diversity. And stay healthy!