Food for the body and soul

Chicken soup, in its many guises, has long been associated with curing illnesses, but how?

There is something strangely reassuring about a classic that's not at risk of being updated. It may not be glamorous, but when made well and using good ingredients, a good chicken soup is hard to beat.

Recently, I made a pot of velvety, tart, Greek avgolemono, known as tarbiya in Arabic: a soup with lemon, egg, white rice and chunks of roasted chicken. I'm considering spending my retirement running an International House of Chicken Soup - a pop-up restaurant whose location migrates by the season and goes where cold and flu are thriving. It offers the kind of psychic nourishment that's capable of countering excess, supplementing a deficiency, and it's guaranteed to make just about anyone happy.

Chicken soup recipes are proof that grandma really did know best; it's food for body and soul. The staggering series of feel-good books – and now films, too – released under the Chicken Soup for the Soul trademark umbrella just further compounds the soup's reputation for being pretty benevolent. Chicken soup is the Little Miss Perfect of the food world.

The recipe I use for chicken soup is based on a widely cited study published in the medical journal Chest in 2000. Dr Stephen Rennard of Omaha, Nebraska, conducted lab tests to try to find out why chicken soup appeared to help colds, and he started with his wife Barbara's recipe, passed down by her Lithuanian grandmother. What Rennard found led him to believe that chicken soup could play an active role in curbing the likelihood of developing upper respiratory cold symptoms, by inhibiting the migration of neutrophils (infection-fighting white blood cells).

Nobody could identify the specific ingredient or synergy of ingredients in the soup that explained its efficacy in fighting cold and flu symptoms. Some say it's just a magical combination. The recipe contained chicken, onions, sweet potatoes, parsnips, turnips, parsley, carrots, celery stems, salt and pepper. There's a lot of information out there demystifying the healing properties of chicken soup, singing its praises, and claiming that what it lacks in mystery it makes up for in magic, like having superior anti-inflammatory powers.

The researchers also compared a number of soups, and interestingly enough, those were also found to affect neutrophil migration. It might explain why my college roommate, who lived exclusively on canned chicken noodle soup, never seemed to get sick, whereas my sandwich diet seemed to land me everything that came down the pike.

The world is filled with greatness in the form of chicken soup. Ajiaco is a Colombian chicken and potato soup, eaten with sliced avocado and boiled corn on the side. Individual diners are left to their own devices with serve-yourself bowls of shredded chicken, cool sour cream, briny little capers to cut through the richness and an onion and coriander-based chilli sauce for garnishing the soup to their liking.

Canja de galinha is a delicious chicken and pasta soup with lemon and mint, eaten in Portugal and Brazil, where it is widely believed to help a person overcome colds, digestive problems and other mild forms of sickness. And though I'd like to feel differently, I've never really liked Chinese egg-drop or egg-flower soup, a dish of wispy ribbons of beaten egg in steaming chicken broth. I love to use a traditional clay cazuela to make a Spanish chicken soup with smoked paprika to serve with toasted bread slathered in aioli.

Generally, however, it's all about the broth. Bouillon, in French cuisine, is simply broth, usually made by the simmering of a bouquet garni and mirepoix (celery, onions and carrots) with bones and vegetables in boiling water. Cock-a-leekie is a Scottish chicken and leek soup whose integrity depends on the quality of the stock used. A bowl of the greatest handmade Japanese noodles is a total travesty without a richly flavoured broth.

My favourite Asian soups are, not surprisingly, chicken soups. Korean samgyetang, a slow-cooked chicken and ginseng soup with garlic, jujubes, chestnuts and sticky rice, is traditionally served on the hottest day of the year. And soto ayam is an Indonesian spicy shredded chicken soup with rice cakes and a variety of garnishes, which may include powdered prawn crackers, a hard-boiled egg and slivers of crispy fried onion.