Chicken soup is good for the soul, they say. And as a homespun remedy for everything that might ail you during winter, there are few things as deliciously soothing.  Could such a broth be more than just a cold comfort? According to the latest scientific study, the answer is yes.

Research in the American Journal of Therapeutics showed that a compound found in chicken soup – carnosine – helped the body’s immune system to fight the early stages of flu.  The authors warned this benefit ended as soon as the soup was excreted by the body, so that means you may need to have a fairly constant supply.

The study wasn’t the first to look at this. More than a decade ago, Dr Stephen Rennard, of the University of Nebraska Medical Center, Omaha, wanted to find out why his wife’s recipe for chicken soup, handed down through generations, was so healing.

Using blood samples from volunteers, he showed that the soup inhibited the movement of the most common type of white blood cell, neutrophils, which defend against infection.

Dr Rennard theorised that by inhibiting the migration of these infection-fighting cells in the body, chicken soup helps reduce upper respiratory cold symptoms.

What he couldn’t do was identify the exact ingredients in the soup that made it effective against colds.  The tested soup contained chicken, onions, sweet potatoes, parsnips, turnips, carrots, celery stems, parsley, salt and pepper.

The researchers also found many commercial soups had a similar inhibitory effect. It is probable that the combination of nutrients worked in synergy to provide the beneficial effect.

Another study, from Miami, also suggests chicken soup has more than a placebo effect. It looked at how consuming it affected air flow and mucus in the noses of 15 volunteers who drank cold water, hot water or chicken soup.

It proved what ENT surgeons (experts in the upper airways, including the larynx) have long known: hot fluids help increase the movement of nasal mucus.  This in turn clears the airways, easing congestion, but soup did a better job than the hot water as it also improves the function of protective cilia, the tiny hairlike projections in the nose that prevent contagions from entering the body.

Researchers at the University of Nebraska found the combination of vegetables and poultry in soup could help alleviate respiratory tract inflammation that results in feeling bunged-up.

All nutrients have some involvement in the complex workings of the immune system. But we know certain things about some of the common ingredients of broth.

2 tablespoons/15ml coconut oil

1 teaspoon/5ml salt

1/2 teaspoon/2ml ground black pepper

1 whole chicken, about 4 to 5 pounds

2-2.5kg3 large leeks, cleaned and sliced thin

3 carrots, sliced in bite sized rounds

3 celery sticks, diced

6 cloves garlic, thinly sliced

2 teaspoons/10ml fresh thyme, minced

2 whole sprigs fresh rosemary, minced

2 tablespoons/30ml flour

1 cup/250ml white wine, sherry or vermouth

6 cups/1.5 liters low sodium chicken stock

2 bay leaves

4 large handfuls of winter greens, chard, kale, beet greens, chopped

1/4 cup/60ml parsley, chopped

Remove all but 2 tablespoons of oil in pot, you can reserve the drippings and rendered chicken fat for dumplings or just discard. Saute leeks, carrots and celery until soft, about 4-5 minutes. Add half of the thinly sliced garlic and minced herbs, stirring for another 30 seconds. Sprinkle with flour and stir for another minute.

Using a heavy wooden spoon, scrape of the browned bits from the bottom of the pot as you add the wine. As the bottom becomes clean add chicken stock. Return chicken and any accumulated drippings to pot. Cover and cook until chicken is tender and will easily pull apart, about 40-50 minutes. If using chopped potatoes, turnips, parsnips or sweet potatoes, add after 20 minutes.

Remove chicken and whole herbs from pot, discard herbs. Remove meat from chicken, discarding bones. Return chicken meat to pot and stir in along with the rest of the garlic, greens and parsley. Cook until greens are tender, about 5 minutes. Serve hot, alone, with noodles, or wild rice.