How to Build a Good Immune System

The immune system is not a wall built in a single night; it should be like a solid building whose foundation is laid well and onto which balanced bricks are placed every day. Here is what to avoid and what to do for a strong and balanced immune system.

What to avoid (the things that bring the system down from within)

Refined sugar and processed foods temporarily paralyze the ability of immune cells (phagocytes) to destroy bacteria. Chronic stress, depression and the cortisol trap keep the body permanently in "fight or flight" mode and trigger cortisol release; this hormone is the greatest enemy that suppresses the immune response. A sedentary, inactive life slows down lymph circulation, the body's waste-collection system, and when toxins cannot be removed, the system becomes clogged.

Insufficient and poor-quality sleep is another problem, because the body produces its defense proteins, the cytokines, mainly during sleep; sleeplessness is like leaving the army without ammunition. Excessive alcohol and smoking both weaken the lung barrier and tire the liver, lowering its capacity to clear toxins. Medicines that lower immunity (cortisones, chemotherapy, and unnecessary use of antibiotics) reduce the strength of immune cells. Finally, inadequate food intake, with a diet lacking proteins, vitamins, minerals and antioxidants, gradually weakens the immune system.

What to do (the things that reinforce the system)

Eat the rainbow: vitamin C alone is not enough. The more colorful your plate, the more phytonutrients you take in. From purple cabbage to green peppers, from orange carrots to red beets, cabbage and peppers, every color supports a different defense unit.

Probiotic and fermented foods matter because 70–80% of the immune system is in the gut. These foods strengthen the gut flora and increase the number of "friendly bacteria." Foods rich in probiotics include homemade yogurt, cheese, tarhana, pickles and kefir. Foods rich in prebiotics include okra, leeks, garlic, apples, Jerusalem artichoke and bananas.

Vitamin D supplementation, taken in a controlled way, is also important: vitamin D is a key for the activation of immune cells. Not being deprived of sunlight and taking vitamin D supplements strengthen immunity. Vitamin D levels below the 30s can bring out immune problems.

Do not underestimate the power of spices. Turmeric (curcumin), ginger, cinnamon, red pepper and garlic (allicin) act as natural antibiotics and anti-inflammatories. Never leaving these off the table strengthens the fortress from within. Drinking enough water matters too, since water is the main component of blood and lymph fluid; drinking water speeds up the delivery of nutrients to the cells and the removal of waste.

Spend time outdoors and do moderate exercise: a 30-minute brisk walk a day helps immune cells patrol the body faster. Protein and omega-3 are valuable as well; adding protein-rich foods such as eggs, white and red meat, dairy and legumes, and omega-3-rich fish such as sardines, anchovies, mackerel and salmon (steamed or baked) to the diet strengthens the immune system.

If you want an even stronger immune system, make use of antioxidants too, especially catechins (black and green tea), lycopene (tomato, watermelon), quercetin (apple, onion), anthocyanins (black plum, black grape, cherry, sour cherry) and beta-carotene (carrot, pumpkin). And do not forget good relationships and a good life: happiness hormones strengthen immunity.

Remember, your immune system is like an insurance policy; you build it up "in installments" over time through healthy habits such as diet, sleep and exercise. If you stop investing in your policy, you will sadly find it out of coverage just when you need it most. The choice is yours: either take good care of your body and keep your immunity strong, or leave the doors defenseless against invaders.