When you're sick, there are few things more nourishing than a warm, savory bowl of chicken soup. Though soup recipes vary, chicken broth is a remedy for cold and flu symptoms utilized around the world; its magic is recognized almost ubiquitously.

But what is it that makes chicken soup so soothing? One dietician, Sandy Allonen, at Beth Israel Deaconess Medical Center in Boston, has laid out exactly what makes this miracle food so wholesome, reports MedicalXpress.com.

"Studies have shown that a hearty bowl of chicken noodle soup may help clear nasal congestion and ease cold symptoms," said Allonen. "It's all about the ingredients."

The core of any good soup remedy is the fact that it helps keep you hydrated.

"A clear broth is warm and soothing, making it a great source of hydration while you're sick, especially if you have a sore throat," she added.

Of course, though, any old soup can keep you hydrated. One of the things that makes chicken soup so especially comforting, however, is the fact that it's an excellent source of tryptophan, which helps your body produce serotonin, a mood-enhancing neurotransmitter. This can be a real game-changer when you're dealing with debilitating cold symptoms.

Chicken can also be a good source of some key immunity-boosting nutrients like B vitamins.

Spices aren't just window dressing

It's not just about the chicken, though. The seasonings added to chicken soup recipes can enhance it significantly, even seasonings that are typically viewed as unhealthy additions, like salt.

"You may think added salt and other seasonings aren't great for you, but in moderation, these spices can help combat the feeling of dull taste buds," noted Allonen. "A loss of taste is common in a cold, but as with any flavor enhancer, salt is great for getting you to eat more."

Even noodles can be a welcome addition, because carbohydrates help add calories when you might otherwise have a loss of appetite. That gives you energy, which your body needs to combat illness.

Most chicken soups are also loaded with healthy vegetables that add to its nutrient content. Common combinations involving carrots, celery, and onion infuse the broth with vitamins C and K, as well as other antioxidants and minerals.

And then there's also just the steam that a hearty soup provides, which opens airways and even has a mild anti-inflammatory effect that can help relax your muscles.

So if you're feeling down this cold and flu season, this is one remedy that both moms everywhere and scientists can agree on: eat your chicken soup.

How chicken soup makes you feel better, according to science
The secret to chicken soup's medicinal properties have been revealed by dietician Sandy Allonen.