Dietary Guidance in Psoriasis: Evidence-Based Supportive Strategies

Announcer:
You’re listening to On the Frontlines of Psoriasis on ReachMD. And now, here’s your host, Ryan Quigley.

Ryan:
This is On the Frontlines of Psoriasis on ReachMD. I’m Ryan Quigley, and today I’m joined by Dr. Peter Lio to discuss the evolving role of diet in psoriasis care. Dr. Lio is a Clinical Assistant Professor of Dermatology and Pediatrics at Northwestern University Feinberg School of Medicine and a dermatologist at Medical Dermatology Associates of Chicago.

Dr. Lio, welcome to the program. It’s great to have you back joining us.

Dr. Lio:
Thank you so much for having me. It’s a pleasure.

Ryan:
Absolutely. So, first off, I want to start off with some basics here, Dr. Lio. What can you tell us about the relationship between diet and psoriasis pathogenesis?

Dr. Lio:
So it’s really an exciting area, and there has been a lot of progress just in the last few years. This is one of those evergreen topics where it seems like no matter when you dip into the literature, you’re going to have new learnings and new ideas. And honestly, all of this is contributing more to our understanding that psoriasis really is a systemic disease, that it is pretty complex, and that the overall health of the patient has an enormous effect on psoriasis itself. So we’ve really gone from this being a skin thing that’s just inflammatory to now having this holistic view of it where diet really makes a difference for a lot of patients.

Ryan:
And now, given that relationship, what types of dietary triggers have shown the strongest association with psoriasis flares, at least from your vantage point?

Dr. Lio:
Again, this is a little bit contentious, so I’ll start with the least controversial. I think it is now generally accepted—everybody pretty much agrees—that being overweight definitely makes psoriasis worse for many patients, and we have a whole bunch of interesting mechanisms. It seems to be pro-inflammatory. It probably alters the microbiome, all these different pieces. When we look at the data for weight loss following lifestyle interventions, there is really substantial data that this helps. So losing weight, for patients who are overweight, makes a big difference. I think that is pretty much agreed upon, which is awesome and important.

Now, it’s not easy, and that I think is why some of the new weight loss medications are playing such an important role. And we’re even seeing cross-marketing of the idea that you can be on a psoriasis medicine plus one of the weight loss medicines. That can make a big difference for these patients. And a lot of the details remain to be seen, but I still think the basic concept is right there.

Now, as we get a little bit more contentious or controversial, there’s this connection with celiac disease and gliadin, or gluten sensitivity. So a fascinating point is that, in general, there does seem to be a higher prevalence of patients with celiac disease in the psoriasis population, and thus, those patients, if they really do have an immune response to gluten or gliadin aspect of the gluten and they take that out of their diet, they do better.

Now, that’s not all-comers, but because it seems to be a higher number than the background rate, it’s not ridiculous for psoriasis patients. Ideally, we’d test them first. But even if they didn’t want to be tested, in theory, they could try to be gluten-free or really gliadin-free. You have to be careful because gluten can be in all sorts of different products, from things like soy sauce to being added into other things, so we want to be careful, but it really can make a difference for those patients. And I think that’s on the edge because you can’t make that as a universal statement, but it really does seem that, at least for those patients, that can be a big difference.

And then we sort of go to maybe the most contentious thing, which we’re still learning a lot about, but it’s the idea of just eating healthier overall. And the example that’s often used is a Mediterranean diet. It seems that even when you remove the idea of weight loss, which often happens, obviously, when you’re eating a better diet, eating a Mediterranean diet seems to decrease the risk of psoriasis and decrease the severity. And again, this may be through some other mechanisms and just the fact that it’s an anti-inflammatory diet and things like that, so it’s fascinating.

And then, on the other side, what kinds of triggers are there? There are some interesting studies where patients talk about things that trigger, and gluten and carbs come up. Sugary foods come up. Alcohol comes up. And even things like red meat will come up. So it’s interesting to see that patients attribute certain foods to flare-ups, although I would say that is the least clear in terms of our understanding, except for the gluten piece.

Ryan:
Thank you very much for that. And how about supportive strategies? Are there specific anti-inflammatory foods that show promise in reducing symptoms or improving treatment response? And what would those foods specifically be? Is there anything that stands out immediately to you?

Dr. Lio:
I think the best evidence is for fish oil supplementation, so eating a lot of fish. But when you look at the studies, they are using a lot of fish oil—I mean, a crazy amount. When I pulled these studies, there were a couple. Full disclosure and full transparency, there are other studies that suggest that there wasn’t much measurable improvement. So we have literature that’s a little bit spotty here, but I think there are at least a couple of studies that suggest that for some patients, they’re going to have some good response with fish oil supplement.

When I pull it, it’s so much that I usually am recommending one of the liquid fish oil-based preparations as opposed to capsules because you end up having to take something like eight or nine capsules a day. I have that on my handout. I’m like, “You can also do this, but it’s an awful lot of pills to take.” So you can take the liquid form and just mix it into something or just take it. It tastes kind of gross, but many of the good preparations have a little bit of lemon flavoring, so it’s not that bad.

But they had patients with psoriasis. They all got phototherapy, and then they randomly assigned them to take either fish oil—again, quite a bit—versus an olive oil control, and they really did show a very dramatic difference between these groups. So I feel like fish oil is something we could recommend. Now, again, it’s not totally safe. Some people get some diarrhea with it. It’s very caloric, so again, keeping that in mind. And you have to pick a good quality one because there’s the potential that it could contain heavy metals and other additives and things that are not good for us. But all those caveats aside, I think that’s important.

Other oils have been studied including seal oil, which is kind of interesting—oil from seals compared to soy oil—and they actually found that it seemed to be a little bit better in the seal oil group, and it moved some of their markers towards an anti-inflammatory profile. That one seems a little bit more difficult for us to get, but I think that fish oil could be helpful.

Vitamin D is something that’s also been explored, and it does seem like there’s an inverse correlation. So the lower your vitamin D, the worse your psoriasis is, but again, the literature is a little bit spotty. In fact, in one of the papers—it was pretty good as a randomized controlled trial of 65 patients—they concluded that vitamin D supplementation at a monthly big dose of 100,000 international units per month was not effective for psoriasis. But other ones have suggested there may be an effect. And to me, this suggests that it might depend on the patient population. There might be certain groups of patients who respond well and others who don’t.

Ryan:
For those just tuning in, you’re listening to On the Frontlines of Psoriasis on ReachMD. I’m Ryan Quigley, and I’m speaking with Dr. Peter Lio about dietary triggers and modifications in psoriasis care.

So, Dr. Lio, to continue the conversation, how do you counsel patients about these dietary modifications, especially when the evidence, like you just mentioned, is still evolving?

Dr. Lio:
As we all know, we do not have a whole lot of time per visit. So that’s the other challenge. We’re trying to maximize the 15 minutes, or if you’re really lucky, 30 minutes for a new patient. Some people are even less lucky, and they’re doing two patients in a 15-minute slot, so you have seven and a half minutes to do the entirety of the visit, and you’re trying to really do the highest impact things first.

And that’s why sometimes my patients will come in and all they want to talk about is diet, and I will say, usually, “Listen, I agree with you. I want you to eat healthy, but typically, in my experience, that’s not where the money is. We usually don’t find a great response by just interacting with the diet. I want you to try to eat healthy.” And I usually have some handouts ready. But I’ll say, “We can look at this, but I’m trying to do more higher-impact things first,” and that’s why we’ll focus on things like biologic agents and topical agents to really make a huge difference because I think the dietary things tend to be more of an adjunctive or supportive piece for most patients.

But if they’re totally insistent upon it, I will start with that, but I just don’t want to waste too much time because in my honest experience, when you look at these studies, almost nobody has complete clearance. It’s not like their psoriasis is cured from these things. It just gets a bit better. And that’s important to know because I think a lot of patients assume or want to believe—and I would love it if this were the case—the “root cause” is just dietary stuff, so all you’ve got to do is fix your diet and things will get better. But I remind my patients that psoriasis is a truly ancient disease. It was mentioned in the Ebers Papyrus, and I don’t think the ancient Egyptians were eating pizza and junk food, right? I mean, they didn’t have it.

Ryan:
And now, Dr. Lio, before we wrap up, what are some key takeaways that you would like to leave with our audience about the relationship between diet and psoriasis?

Dr. Lio:
I think my big takeaways are it’s really important not to just dismiss it—I think it upsets patients, and I’ve learned this the hard way many times over the years. You don’t want to dismiss it, so talking about it at least a little bit is important. I think putting it into the proper context, though, is important, too—“This probably, unfortunately, isn’t the root cause. This isn’t going to solve everything. That being said, it is really important that you eat healthy, and I think we can talk about avoiding things that seem to make it worse, like alcohol and lots of red meat and some of the processed foods that seem to drive this. Keeping an eye on our weight and staying at a healthy weight is really important. Doing that either with conventional dietary and lifestyle change, that’s A+.” That’s what we want, but a lot of patients can’t. So then also talking about weight loss techniques and medications that may help, I think, is very reasonable.

And then the third piece is putting it into the context of also doing this alongside of the best treatments that we have because psoriasis is pretty terrible, and if people are just suffering and waiting for the diet to make a huge difference, I don’t think that’s fair to them. Ideally, we would use the powerful treatments that we have alongside these lifestyle changes and then hopefully get to the point where they say, “Gosh, I don’t really need my strong medicines anymore,” or, “I’m using way less of my topical steroids, and my quality of life is improved.” At the end of the day, that’s really what we’re aiming for.

Ryan:
Well, that is a great way to wrap up our program. And I want to thank my guest, Dr. Peter Lio, for joining me to share his insights on the role of diet in psoriasis management.

Dr. Lio, it was a pleasure having you on the program. Thanks so much for doing this.

Dr. Lio:
Thank you again for having me back.

Announcer:
You’ve been listening to On the Frontlines of Psoriasis on ReachMD. To access this and other episodes in our series, visit On the Frontlines of Psoriasis on ReachMD.com, where you can Be Part of the Knowledge. Thanks for listening!