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A
Hello and welcome to Zoe Recap, where each week we find the best bits from one of our podcast episodes to help you improve your health. Today we're talking about arthritis. It might not sound as serious as cancer or heart disease, but arthritis can have a huge impact on your quality of life, turning simple movements into painful tasks. But here's the good news. Emerging research suggests that diet can have a huge impact on the symptoms of arthritis, helping to lower inflammation and even reduce the risk of the disease developing. I'm joined by Dr. Tamiko Katsumoto to explore how simple changes to what's on our plate can help protect our joints. It's been eight years since I co founded Zoe, and I think every year I've just got more and more shocked at the way in which the food that we're eating, you know, across the western world is making us so sick, but also just discovering each year about ways in which it affects us that I had no idea about. So today we're talking to you as a professor of immunology and rheumatology at Stanford about arthritis and how it's linked to food. And I never would have guessed when I found it, Zoe, that it could have anything to do with food. In fact, I would have said that was, you know, like crazy, totally non scientific. So it's amazing how much I think my understanding has changed. What is arthritis and how does that relate to this concept of inflammation, which I know is a lot about what you study.
B
I'm a rheumatologist, so I take care of patients with arthritis with a lot of other inflammation of other organs. So rheumatoid arthritis, lupus vasculitis, you know, psoriatic arthritis, you name it. I think arthritis is complex. Basically. Our joints are, are generally protected areas where you've got your bone, you've got a synovial lining, you've got this nice joint capsule that is lubricated so that it allows us to move freely. The problem is, with inflammation, there can actually be a breach of those protective barriers such that you can end up getting inflammation. There's actually connection with the gut and mucosal barriers that play into the inflammation, leading to arthritis.
A
And Tamiko, I know nothing about how my joints work. And I could see you're sort of painting a picture of. I'm sort of imagining somehow something, I don't know, a bit quite mechanical with some oil running. Is that the right analogy? Is that what you described? Could you just help me to understand a bit?
B
Yeah, I think that, you know, it's actually, I'm thinking about this. There's a lot of analogies. We talk a lot. I know Zoe talks a lot about the gut and how there's this important lining of the gut. Similarly, I think you can think about the joint in that there's an important lining called the synovial lining of the joint that can get breached when you end up having, let's say, T cells that are recognizing some of the synovial proteins. So the joint proteins there can actually be what's called an autoimmune attack, where your own T cells can end up invading the joint, causing inflammation. It causes a leaky joint, if you will. We've heard about leaky gut, and I think what we've started to learn over the course of many years of research is that these mucosal breaches, for example, in our gut, even in our mouth or oral microbiome, can stimulate certain bacteria that may actually cause our immune system to wake up. T cells that are attacking these specific bugs in our gut, in our mouth, can end up actually getting confused and attacking our joints. So this is a whole hypothesis that's coming to fruition with some very exciting science recently in terms of how our immune system can be connected to joint inflammation.
A
So, Tomiko, if I understand rightly what you're saying is, like, I'm not experiencing any arthritis today, so I can sort of move all my joints around and they're able to sort of slide around somehow really smoothly. I'm thinking a bit like a sort of Teflon pan or something like that. But you're saying that what can happen is my own immune system ends up attacking, like, parts of these joints and breaking that Teflon, and then suddenly it's both painful and does not move as smoothly.
B
Exactly.
A
I don't know if I'm stretching this analogy way too far.
B
Yes. No, it's a great one. I think that it's either immune attack that can lead to the disruption of this nice synovial barrier that can lead to arthritis. My patients end up getting very swollen, tender, red hot, painful, stiff joints. Other ways that this can happen are through damaged responses. So one thing that a lot of people may have heard about is a condition called gout, and that would be a crystal. There's a crystal called uric acid, which is a byproduct of a lot of cellular metabolism. And those uric acid crystals can end up building up in our joints, and that can end up triggering this inflammatory response as well.
A
Can you help us to understand how this change in what you're eating could suddenly stop your joints being inflamed and in pain, because, you know, the link is not obvious.
B
I think it's complex and multifactorial. Simply speaking, I will say we know a lot of our dietary components, like sugar, you know, a lot of these, you know, saturated fat, processed foods drives inflammation in various ways. I think one of the primary ways is through how it, you know, how it affects our gut microbiome. I think that, you know, we end up assaulting our important gut barrier with loading it with all this sugar and fat and these emulsifiers and food colors and other processed things that are really insulting the gut barrier. And that is leading to this systemic inflammation. And so by simply improving our diet, improving our gut health, decreasing the dysbiosis that we experience, I think that that is leading to these improvements in our joints.
A
So tell me what's on the plate?
B
You know, I like the kind of my plate. This is sort of the approach where you take a plate and you divide it up and really half of it is fruits, vegetables, you know, good stuff. The whole concept of eating the rainbow, I think really is apropos because these are foods that are high in phytochemicals, a lot of the antioxidants that are super important for calming down our immune system. Cruciferous vegetables. Vegetables. These are things like broccoli and kale and cauliflower and these really kind of the deep leafy greens that I've come to love and embrace. And they're so important. I really think food is medicine, and these are incredibly important in terms of helping our liver detoxify. You know, we're living in a very polluted world, and I think that these are super helpful foods that can help us clear our body of a lot of these toxins, these endocrine disruptors, which we haven't talked about, but there's a lot of these things that we need to be thinking about that are super helpful for my patients. So half of the plate, I think, focusing on high quality vegetables, some fruits, and then a quarter of the plate being proteins, preferably plant proteins or lean proteins, but things like beans and lentils. I'm a big fan of tofu and then whole grains. I think the thing to keep in mind is that, as we know, with our ultra processed foods, we tend to eat a lot of these very refined grains. You know, the white rice, white pasta, white bread. These things that have had a lot of the nutrients stripped out of them and a lot of the fiber stripped out. So refined Grains is where we want to go. And so really whole wheat and whole, you know, things like quinoa I love. And some of these ancient grains are also really good like farro and bulgur and millet, if you kind of imagine, I guess it's really the plate method. The pyramid method is a little more, you know, more complicated to think through. But those are the key staples that I try to encourage my patients to aim for. Again, animal products in moderation, really limiting them. If you look at the blue zones, they say that the majority of blue zones ended up eating meat less than five times a month. So really that comes down to maybe once a week. Meat should be considered a treat. The other thing I'll mention that I love about the blue zones is that one thing that was commonly shared across all the five blue zones is they all ate a, a half to 1 cup of beans a day. Beans or lentils. So these legumes that are so good for us, packed with protein, packed with fiber. Another food type that I love a lot are things like chia seeds and flax seeds. These are, I think chia seeds are the perfect food. They're high in fiber, high in omega 3, high in protein. You know, they've just got so many great components that I add them to my smoothies. I just try to incorporate them wherever I can. I get a big, you know, bottle of them and add them wherever I can.
A
Is there any view around oily fish and arthritis? Because I know that there's a sort of spread of opinion I feel between the people that I interview, but there seems to be quite a lot of people talking about oily fish as being beneficial. In general, you've been talking about very much plant centric diet. What's is, what's the evidence with people with arthritis?
B
So fish I think can be a helpful component because of the omega 3s. So we know omega 3 fatty acids are incredibly anti inflammatory. That being said, I also encourage my patients to not go too heavy on fish to eat the smaller fish. So not so much the tuna and the swordfish, things that are much larger and can end up bio accumulating things like heavy metals and toxins, trying to go for the wild caught instead of the farmed. But again, I would say what do I do? I end up taking The Vegan Omega 3, which is from algal sources, so algae. I think there are different ways of getting omega 3s. I mentioned Chia seeds also have them and there's different types. So fish, I think it can be a good thing but not to overload. And I tend to also recommend I tell my patients Check out The Monterey Bay Aquarium's resource called seafoodwatch.org Seafood Watch has a lot of the examples where fish what's sustainably caught and which ones are thought to be healthier. You know we have to be thinking about pollutants. Our oceans are not the cleanest, so we have to be thinking about that as well.
A
As you can imagine hosting this podcast, running Zoe, juggling family life. It all keeps me pretty busy. So I try as best I can to stay energized and show up well in all those parts of my life by fueling my body with the right food, by exercising, and by adding a scoop of daily 30 to my meals every day. If you haven't heard of Daily 30 yet, it's the gut supplement designed by our gut health scientists here at Zoe. It's made of over 30 high quality hand picked plants including seaweed, fungi and different types of fiber. Better yet, it contains ingredients that support gut health, digestion and energy, which is ideal for packed calendars and busy lives. Simply add one scoop a day to any meal for an extra boost of fiber and plant diversity. And because it tastes delicious on just about anything and adds a satisfying crunch, it quite quickly slots into your life, becoming a daily healthy habit you'll always have time for. By the way, whenever we talk about Daily 30 as a good source of fiber, we're required to say that it contains 4 grams of total fat per serving. Obviously that's all amazing healthy fats from plants, so order yours today@zoe.com daily30. Thanks for listening and see you next time.
Guest: Dr. Tamiko Katsumoto (Stanford Professor of Immunology & Rheumatology)
Host: Jonathan Wolf
Date: February 10, 2026
This episode of ZOE Science & Nutrition focuses on arthritis—its causes, how it’s intricately linked to inflammation, and most importantly, how diet can support joint health and reduce the risk of developing arthritis. Host Jonathan Wolf and Dr. Tamiko Katsumoto discuss the latest scientific findings connecting gut health, immune function, and nutrition to arthritis prevention and management. Dr. Katsumoto breaks down the science into relatable analogies and gives actionable advice on what to eat to lower arthritis risk.
Inflammation as Root Cause:
Dr. Katsumoto explains that arthritis is complex but fundamentally driven by inflammation, which occurs when the protective barriers of joints are breached.
"Basically, our joints are generally protected areas... The problem is, with inflammation, there can actually be a breach of those protective barriers..."
(01:35 – Dr. Tamiko Katsumoto)
Immune System’s Role & Autoimmunity:
The immune system can misidentify joint proteins as threats, attacking them and causing pain and stiffness—akin to a “leaky joint.”
"It causes a leaky joint, if you will. We've heard about leaky gut... certain bacteria... may actually cause our immune system to wake up... and attacking our joints."
(02:37 – Dr. Tamiko Katsumoto)
Role of the Gut and Microbiome:
There is a strong emerging link between mucosal breaches (like 'leaky gut') and joint inflammation. Dysbiosis (disruption of gut microbiota) can trigger or worsen inflammation in joints.
Processed Foods Drive Inflammation:
Diets high in sugar, saturated fats, and processed foods negatively impact the gut barrier and promote systemic inflammation, increasing arthritis risk.
"We end up assaulting our important gut barrier with loading it with all this sugar and fat... that is leading to this systemic inflammation."
(05:18 – Dr. Tamiko Katsumoto)
Improving Diet for Joint Health:
Moving to a whole-food, plant-based diet helps reduce inflammation:
"These are foods that are high in phytochemicals, a lot of the antioxidants that are super important for calming down our immune system."
(06:18 – Dr. Tamiko Katsumoto)
Animal products should be limited, ideally as occasional treats rather than staples.
Blue Zones & Beans:
Dr. Katsumoto references longevity research in “Blue Zones,” where lower meat consumption and daily intake of legumes are common.
"The majority of blue zones ended up eating meat less than five times a month... one thing that was commonly shared across all the five blue zones is they all ate a half to 1 cup of beans a day."
(06:18 – Dr. Tamiko Katsumoto)
Seeds as Superfoods:
Special mention is given to chia seeds and flax seeds for their fiber, omega-3, and protein content.
"Chia seeds are the perfect food... they've just got so many great components that I add them to my smoothies. I just try to incorporate them wherever I can."
(07:56 – Dr. Tamiko Katsumoto)
Fish Can Be Helpful, With Caveats:
Oily fish provide omega-3 fatty acids, which are anti-inflammatory—beneficial for arthritis. However, Dr. Katsumoto advises moderation and choosing smaller, wild-caught fish to minimize exposure to heavy metals and pollutants.
"Fish I think can be a helpful component because of the omega 3s... I also encourage my patients to... eat the smaller fish... Again, I would say what do I do? I end up taking The Vegan Omega 3, which is from algal sources."
(09:46 – Dr. Tamiko Katsumoto)
Plant-Based Omega-3s:
She personally prefers vegan omegas (from algae) and plant sources like chia seeds.
Guideline for Fish Consumption:
"Seafoodwatch.org... has a lot of the examples where fish what's sustainably caught and which ones are thought to be healthier. You know, we have to be thinking about pollutants."
(10:23 – Dr. Tamiko Katsumoto)
On the mechanical analogy of joints:
"I'm sort of imagining somehow... a bit quite mechanical with some oil running. Is that the right analogy?"
(02:20 – Jonathan Wolf)
"I think that it's either immune attack that can lead to the disruption of this nice synovial barrier that can lead to arthritis."
(04:24 – Dr. Tamiko Katsumoto)
On food as preventive medicine:
"I really think food is medicine, and these are incredibly important in terms of helping our liver detoxify... packed with protein, packed with fiber."
(06:18 – Dr. Tamiko Katsumoto)
On the prevalence of processed foods:
"With our ultra processed foods, we tend to eat a lot of these very refined grains... that have had a lot of the nutrients stripped out of them."
(07:06 – Dr. Tamiko Katsumoto)
This episode provides science-backed, actionable advice for anyone looking to prevent or manage arthritis through nutrition, emphasizing practical changes that can make a significant difference in joint health and overall well-being.