Your immune system needs energy, especially when infection is present. Under attack from bacteria and viruses the body makes remarkable and rapid changes. Cells and antibodies are directed into blood and saliva but new cell production in the blood, usually a high priority for the body, temporarily stalls. Digestive processes turn off and calories are rapidly consumed by the immune system's new energy needs.
Feed a fever
Traditional biochemistry believed that fever is the bug or illness active in our body, but recent research suggests that fever is mainly your immune system in action, heating up to make the body a hostile environment for the bugs attacking us. They call this 'Immune Brinkmanship': the body making itself (and you) uncomfortable to make it 'too hot' for the bugs to survive.
Whatever the cause, fever consumes a lot of energy. Maintaining mild-fever in an 80kg person needs more than 250 calories daily. It takes the same person 168 calories to run the heart and 373 for the brain. This energy use has a noticeable cost, increased fatigue and a decreased interest in things we usually enjoy and have energy for. It's all about conserving energy for the immune system which explains our natural responses to illness of social withdrawal and lots of sleep.
Preparing beats recovering
Food is fuel so look at what and how you are eating. Understanding the Glycemic Index is a big help. Think slow-cooked food for long-lasting energy (see sidebar). An immune building food-pyramid is built on green leaves and veges. The ideal is make 30-40% of your total diet crisp (not overcooked) or raw veges. 20-30% fruit, beans and legumes, with oily fish, non-meat proteins, wholegrains making the bulk of the remainder with lean meats and dairy the smallest peak of your winter bug-battling food pyramid plan.
Edible immunity
Maximise
Make 5 plus a day servings of fruit and vege your minimum
Eat half your daily vegetables raw, to retain their micronutrients
Have a large salad of greens, tomatoes and raw vegetables every day. Try a wintry soups of beans/legumes (lentils and chickpeas), with mushrooms, garlic and onions
Nuts and seeds
Kale, watercress, Brussels sprouts, spinach, broccoli, cauliflower, leeks carrots
Citrus, kiwifruit, berries, pomegranate, cherries, plums
Minimise
All animal products
Grains
Alcohol
Caffeine
Avoid
Processed, cured or barbecued meats
Sugar
There are many supplements proven to boost immunity, which I will cover more completely in another article.
You are your immune system
Made up of multiple cells and organs, your immune system is integrated with the nervous, cardiovascular and respiratory systems. Immunity is just one of many potential biological priorities and unlike the lungs, heart and brain, the immune system demands high priority only when an infection is present.
The immune system has two key functions: recognise viruses, bacteria, fungi, microbes and parasites in the body and destroy them.
