Is Bone Broth Good for You? Grandma Was Half Right

Creator: Robin Berzin MD
Published: 2026-10-20T13:00:00.000Z

Bone broth isn’t liquid gold. Here’s what the evidence says about broth, miso, seaweed, protein, iodine and building a better winter bowl.

By Robin Berzin MDColumbia-trained physician · Founder of Parsley HealthPublished October 20, 2026·9 min read

Robin's Short Version

Bone broth is a useful source of protein and hydration, but it is not a meaningful mineral supplement or a proven gut-healing cure.
Fermented soy has the strongest longevity evidence: higher miso and natto intake was associated with lower mortality in a large Japanese cohort.
Seaweed can supply iodine, but kombu and frequent seaweed soup can push intake too high—especially during pregnancy, breastfeeding or with a thyroid condition.
For a more complete meal, choose broth with about 10 grams of protein per cup and add egg, chicken, tofu or beans.

Bone broth isn't liquid gold. But the right broth might be the easiest longevity habit of the winter.

I grew up on chicken soup as a salve in various forms: instant, matzah ball, homemade. Every cold, every sick day, a bowl appeared. Nobody questioned it.

This week in New York, the temperature dropped 20 degrees. Fall showed up overnight. And I've been craving broth again, a substance I haven’t thought about once in six months and now it’s all I want as I stand shivering on the soccer field with my kids.

Right on cue, I was introduced to OMA by a friend — a Korean seaweed soup made with beef bone broth. Two minutes, just add water. I am hooked.

Which made me want to dive into the science more deeply. Is bone broth a superfood? What about miso? Seaweed? Chicken beef or marine? Or is it all just comfort in a cup?

Short answer: some of it holds up. A lot of it is hype.

This week: what's real, what's not, and what I'm sipping this winter.

⚡ Forward this protocol

One warm mug a day. Make it count.

One warm mug of broth a day. Here’s how to make it count.

Choose bone broth or miso. Look for bone broth with ~10 g protein per cup. Miso is the fermented option, the one most linked to longevity.
Make it a meal. Add an egg, chicken or tofu to get past 20 g of protein. For seaweed, a pinch of wakame or nori. Kombu only occasionally: it’s so high in iodine that daily can be too much for your thyroid.

👉 Forward this to the friend who drinks bone broth like it's a supplement.

What to know: Broth is a vehicle, not a miracle.

❌ The old assumption: Bone broth is liquid gold, packed with minerals and collagen that heal your gut.

✅ The new reality: Broth is a warm, hydrating way to deliver whatever you put in it. The magic is in the mug, not the bones.

Grandma was half right.

Hot chicken soup sped up mucus clearance more than hot water did. Cold water slowed it down ¹. In a lab dish, chicken soup also calmed the white blood cells that drive cold inflammation — and the chicken and every vegetable in the pot had the effect on their own ².

Decongestant? Yes. Cure? No.

Bone broth is protein, not a mineral supplement.

Homemade and store-bought broths delivered under 5% of your daily calcium and magnesium per serving ³. The collagen building blocks varied wildly from batch to batch, and fell well short of a 20-gram collagen supplement ⁴.

And the claim that bone broth “heals your gut”? The best evidence so far is in mice. In mice with colitis, bone broth calmed inflammation in the colon ⁵. Promising, but we don’t have human trials yet.

What a good bone broth does give you: about 10 grams of protein in a warm, hydrating mug. Useful. Just not magic.

Miso has the best receipts.

In 92,915 Japanese adults followed for almost 15 years, those who ate the most fermented soy (miso and natto) had about a 10% lower risk of dying. Tofu and soy milk? No link ⁶. Fermentation seems to be the point.

And for women, miso on its own was enough: 11% lower risk.

In 21,852 Japanese women, miso soup and soy isoflavones were linked to lower breast cancer risk, especially after menopause. The highest isoflavone intake: 54% lower ⁷.

The salt? How often people ate miso soup wasn't tied to their blood pressure ⁸. It's still salty. If your blood pressure runs high, it counts.

❝ In women, miso alone was linked to an 11% lower risk of dying.

Seaweed: the dose is everything.

Japanese gut bacteria borrowed seaweed-digesting genes from ocean bacteria ⁹. Your microbiome adapts to what you feed it.

But seaweed's big nutrient is iodine. You need 150 micrograms a day, 290 if you're breastfeeding. The upper limit is 1,100 ¹⁰. Kombu has the most, and boiling it releases about 99% of its iodine into the water ¹¹. Translation: kombu broth is where the iodine lives. Healthy adults eating 15 grams of kombu a day saw their Thyroid Stimulating Hormone (TSH) rise, above normal in some ¹².

New moms, this one's for you. Korean postpartum seaweed soup averages about 1,700 micrograms of iodine per bowl, and most new moms in Korea eat it three times a day the first week ¹³. That iodine passes into breast milk. Doctors have reported newborns with underactive thyroids linked to mom's seaweed soup ¹⁴.

A beautiful tradition. Just not five bowls a day.

What to do: Build a better bowl.

1️⃣ Pick a real bone broth.

Read the label, not the marketing.

~10 g protein per cup
under ~400 mg sodium
short ingredient list, organic or grass-fed bones
it jiggles when cold (that's the gelatin)

My picks: Brodo — born in a window in the East Village, 10 g protein and 350 mg sodium per cup — and Kettle & Fire for the pantry, 19 g protein per carton.

2️⃣ Make miso your weeknight broth.

1 Tbsp miso per cup of hot (not boiling) broth or water, stirred in off the heat to keep the live cultures
add tofu, scallions and a pinch of wakame
plant-based? Add ½ cup white beans for more protein

3️⃣ One seaweed serving a day.

wakame or nori day to day; kombu occasionally
one OMA bowl covers it: 35 calories, 310 mg sodium and about 113% of your daily iodine. Add an egg or chicken to make it a meal. Heads up: it contains wheat so it not GF for those who avoid gluten.
don't stack seaweed soup + kombu dashi + kelp supplements (too much iodine!)
pregnant, breastfeeding or have a thyroid condition? Talk to your doctor first or limit frequency

4️⃣ Sick? Go hot.

Hot soup beats cold drinks for congestion. Load it with garlic, ginger and vegetables.

⭐ If you do one thing: Swap your afternoon snack for a mug of real bone broth or miso.

The goal: Keep the ritual. Upgrade what's in the mug.

Living Longevity

This weekend my husband threw me a surprise party. I don’t think I’ve ever had a surprise party in my life, and I loved it. The occasion: my transition from CEO of Parsley to board chair and Chief Health Officer after 11 years. My best friend decoyed me with drinks, and when I walked into my house, 30 people — including my 9-year-old — yelled SURPRISE!!! It was such a great feeling.

I’m at a fulcrum moment in my life: turning 45 this year, closing out my fertility, entering perimenopause, and evolving my career meaningfully for the first time since I left medical training. Marking the occasion is part of how I’m celebrating my own longevity. We can experience time as a celebration. We can ignore it as we power through life. Or we can use it as a measuring stick: Have I accomplished what I wanted to at this point in my life? Why or why not? Has my definition of success changed?

This week I’m working on my talk on female longevity for the upcoming Eudēmonia event in West Palm Beach. I’m speaking four times! If you’re thinking about coming, get a ticket — it’s going to be great. My keynote is on what’s real and what’s myth in female longevity, a space where we’re marketed a lot of solutions but can have trouble sorting signal from noise. My big takeaway: if we aren’t able to see the measurable impact of something we’re doing for our health and longevity in real time — at least within a year — it probably isn’t improving our healthspan or our lifespan. The things that are good for us long term make us better now, not just later. For the science behind why I believe this, you’ll have to come to the talk.

The number one thing I’m doing for my longevity this week is introducing novelty: reading a new book (currently You Are the One You’ve Been Waiting For by Richard Schwartz), giving a new talk on longevity for the Summit community, and trying a new workout, hot Pilates. Simple things, but all new ways of expanding my neurons little by little. A plastic brain is a healthy brain.

I hope you do something different this week too. I hope you give yourself permission to keep changing. And I hope you celebrate the changes along the way.

One more thing... My bone broth recipe

Makes about 3 quarts. Mostly hands-off. Mostly waiting.

Ingredients

3–4 lb bones: chicken backs, necks or wings, plus 1 lb chicken feet for gelatin (or beef knuckle and marrow bones)
2 Tbsp apple cider vinegar (the acid pulls more minerals out of the bones)
1 onion, 2 carrots, 2 celery stalks, roughly chopped
1 head garlic, halved, and a 2-inch piece of ginger
1 bay leaf and 1 tsp peppercorns
a handful of parsley and thyme

How

Beef bones? Roast at 425°F for 30 minutes first. Chicken goes straight in.
Add everything but the herbs to a big pot. Cover with cold filtered water by 2 inches.
Bring to a bare simmer and skim the foam.
Simmer 12–24 hours for chicken, 24–36 for beef. (Instant Pot: 2–3 hours on high.)
Add herbs in the last 30 minutes. Strain, cool, refrigerate.
It should jiggle when cold. Keeps 4–5 days in the fridge, 6 months in the freezer.

To serve

Heat a mug, stir in 1 tsp white miso off the heat, and top with a pinch of wakame and scallions.

References

Originally published in the Off Script newsletter. Join Robin’s readers for weekly functional medicine insights.

As always, this newsletter is for informational and educational purposes only and is not intended as medical advice. Always consult your healthcare provider before making any health decisions or changes to your treatment plan.

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