Bone broth is one of the better things you can reach for when you’re sick, and the reasons go beyond tradition. It delivers fluids, electrolytes, and amino acids in a form your body can absorb easily, even when eating solid food feels impossible. A single cup contains roughly 450 mg of sodium and 280 mg of potassium, two electrolytes you lose rapidly through sweat, fever, vomiting, and diarrhea.
Why It Helps With Congestion
If you’re dealing with a cold, flu, or sinus infection, bone broth works on congestion in a couple of ways. The hot steam loosens mucus in your nasal passages, making it easier to breathe. But something more interesting is happening at the molecular level: bone broth contains cysteine, an amino acid that acts as a building block for a compound called N-acetylcysteine. That compound is actually used as a pharmaceutical mucolytic, meaning it breaks apart the chemical bonds that make mucus thick and sticky, reducing its viscosity so your body can clear it more efficiently.
A well-known study published in the journal Chest found that chicken soup significantly inhibited the movement of neutrophils, a type of white blood cell that drives the inflammatory response in your upper airways. That inflammation is what makes your nose swell shut and your throat feel raw. The effect was concentration-dependent, meaning stronger broth had a stronger effect, and the anti-inflammatory activity came from a combination of the chicken and vegetables together.
Replacing What Illness Takes Away
Fever, sweating, diarrhea, and vomiting all drain your body of fluids and electrolytes fast. The National Institute of Diabetes and Digestive and Kidney Diseases specifically recommends drinking plenty of liquids to replace lost fluids and electrolytes during stomach bugs. Bone broth fits that recommendation well because it delivers sodium and potassium in a warm, palatable form that most people can keep down even when their stomach is unsettled.
Plain water replaces volume but not electrolytes. Sports drinks replace electrolytes but come loaded with sugar, which can worsen diarrhea. Bone broth hits a middle ground: it rehydrates, replenishes minerals, and provides a small amount of protein (about 5 to 6 grams per cup) without requiring your digestive system to work hard. When you have a fever or nausea, your gut is already under stress. Liquid nutrition bypasses the need for significant digestion, which is why it tends to stay down when crackers or toast won’t.
Glycine and Inflammation
Bone broth is rich in glycine, an amino acid that comes from the connective tissue and collagen that dissolve during long simmering. Glycine has notable anti-inflammatory properties. It reduces the production of several key inflammatory signals, including TNF-alpha, IL-6, and IL-1beta, while increasing production of IL-10, which is anti-inflammatory. It does this by blocking a master inflammatory switch called NF-kB.
Why does that matter when you’re sick? Your immune system’s inflammatory response is what causes most of the misery: the fever, the aches, the swollen sinuses, the sore throat. You need some inflammation to fight the infection, but your body often overshoots. Glycine gently dials down that excess without suppressing the immune response entirely. Think of it less like a medication and more like a nudge toward balance.
Gut Protection During Illness
Your intestinal lining is a single layer of cells held together by tight junction proteins, and it takes a beating during illness. Fever, stress hormones, certain medications, and stomach viruses all increase intestinal permeability, sometimes called “leaky gut,” which lets bacteria and toxins slip into your bloodstream and makes you feel even worse.
Glutamine, another amino acid found in bone broth, is the primary fuel source for the cells lining your intestines. It plays a key role in maintaining the integrity of that barrier. When glutamine levels drop, the intestinal lining deteriorates: the tiny finger-like projections that absorb nutrients shrink, tight junction proteins decrease, and permeability increases. Replenishing glutamine helps reverse that process. This is especially relevant during stomach flu or any illness involving GI symptoms, where your gut lining is taking direct damage.
What Makes a Good Sick-Day Broth
Not all bone broths are equal. The longer the simmer, the more collagen, glycine, and glutamine dissolve into the liquid. A broth simmered for at least 8 to 12 hours will have meaningfully more of these compounds than one cooked for 2 hours. You can tell a well-made broth by its texture: it should gel when refrigerated, which indicates high gelatin (and therefore amino acid) content.
Store-bought options vary widely. Look for brands that list bone broth rather than “stock” or “broth flavored” on the label, and check sodium content if you’re watching your intake. Some commercial bone broths are essentially flavored water with very little protein, so checking for at least 8 to 10 grams of protein per serving is a reasonable quality marker.
One concern worth mentioning: bones can accumulate heavy metals like lead, and long simmering can leach small amounts into the broth. Research on commercial bone broth products has found that calcium and magnesium levels per serving are relatively low (magnesium typically ranges from about 14 to 30 mg per serving). The lead levels measured in studies have generally been low, but if you make broth at home regularly, sourcing bones from pasture-raised animals and avoiding extremely long cook times (beyond 24 hours) is a reasonable precaution.
Getting the Most Out of It
Sipping bone broth throughout the day works better than drinking a large amount at once, especially if nausea is an issue. Warming it to a comfortable drinking temperature (not scalding) maximizes the steam benefit for congestion. Adding a pinch of salt if the broth tastes flat can further support electrolyte replacement.
For a cold or upper respiratory infection, the original chicken soup study found that the combination of chicken and vegetables together produced the best anti-inflammatory effect, so adding soft-cooked carrots, celery, onion, or garlic to your broth isn’t just for flavor. Each of those vegetables showed individual inhibitory activity against the inflammatory cells tested. If your stomach can handle it, tossing in some rice noodles or a beaten egg adds calories and protein when you need energy but can’t face a full meal.