Autoimmune conditions occur when your immune system mistakenly identifies normal organs as abnormal and starts to attack them. With psoriasis that attack takes the form of scaly patches on the skin. These diseases are sometimes referred to as “modern plagues” because we’ve seen such an explosion in their incidence. To understand what’s behind that increase, we need to take a look under the hood at what’s going on in the GI tract
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On today’s show…psoriasis. An autoimmune condition where skin cells accumulate into itchy, scaly patches – usually on your knees, elbows, trunk and scalp. A quick refresher on what an autoimmune disease is: it’s when your body mounts an immune response to its own tissue. So your immune system mistakenly identifies normal organs as abnormal and starts to attack them. With psoriasis that attack takes the form of scaly patches on the skin, with ulcerative colitis it’s ulcers in the colon, with rheumatoid arthritis it’s the joints, with MS it’s the brain. There are now over 100 different autoimmune conditions, and 1 in 4 Americans suffers from one – and lots of people suffer from more than one. Autoimmune diseases are sometimes referred to as “modern plagues” because we’ve seen such an explosion in their incidence. And to understand what’s behind that increase, we need to take a look under the hood at what’s going on in the GI tract.
Both genetic predisposition and environmental factors play a role in the development of most autoimmune diseases. But even for diseases where there’s a strong genetic component, it’s ultimately the environmental triggers that turn a genetic predisposition into an actual disease; and a lot of those triggers are happening in the gut.
To illustrate how this works, let me tell you about a brand new study published in the British Journal of Dermatology in July 2024 that provides some insight into what kind of triggers we’re talking about when it comes to psoriasis. Specifically, the role of breastfeeding and early nutrition.
This study used data from a large registry called ABIS, which stands for All Babies In Southeast Sweden and it includes over 17,000 babies born between 1997 and 1999 that have been followed for more than 20 years. The study involved questions about nutrition, infections, psychosocial factors, living conditions, life events, starting at birth and continuing into young adulthood.
One of the first questions the researchers set out to answer was whether breast-feeding was protective against developing psoriasis. And the results showed that yes, it was. Children who were breast-fed for less than four months had a higher risk of psoriasis. And introducing infant formula before four months of age doubled the risk of psoriasis. Human milk oligosaccharides (HMOs) are the third-most common ingredient in breast milk, despite the fact that they’re completely indigestible by infants, because they’re not there to feed the baby. They’re there to feed the baby’s bacteria—species like Bifidobacterium that repel Staphylococcus and other harmful microbes on the mother’s nipple. Compounds in the breast milk like HMOs feed the baby’s growing army of good bacteria that help protect the baby from more harmful species. Breast-fed babies in the US have a 20% higher survival rate than formula-fed babies – and less autoimmune diseases like psoriasis in childhood and adulthood.
The Swedish study also found that early introduction of cow’s milk during infancy was a risk factor for developing psoriasis. And it’s unclear whether that’s because of the milk itself, or because it’s displacing the positive impact of breast milk. Eating a lot of fish from the Baltic Sea was also a risk factor. These are fish that are known to contain a lot of toxic compounds, including heavy metals, that can affect the gut. Similar effects to what we’re seeing in the gut from emulsifiers and preservatives in ultra-processed foods.
One of the major conclusions of the study was that nutrition matters. And in this study, nutrition early in life at age one, was more important than nutrition at age 3. It’s not that nutrition at age 3 wasn’t important, but what the baby was eating in that first year of life was critical for preventing diseases like psoriasis.
That makes sense based on what we know about the development of the microbiome: although it continues to develop up until around age 18, it’s most fragile early in life, when those new species are colonizing the gut and the rest of the body. And that’s why antibiotic use in early childhood when the microbiome is really tender is so devastating, and so strongly associated with autoimmune disease later in life.
Now if you’re an adult and you already have psoriasis you may be thinking that there’s not much you can do about whether you were breastfed or not and what you ate as a baby. And that’s true, but even though the microbiome is relatively stable in adulthood compared to infancy, what you eat is still THE most powerful tool to improve the composition and diversity of your gut microbiome. It’s not prebiotics or probiotics or short chain fatty acid supplements. It’s food. And of course, that dietary influence on your gut can be either positive or negative depending on what you’re eating.
We could spend days talking about the impact of food on the gut microbiome and how that can affect different diseases, but Michael Pollan actually summed it up nicely in seven words: “Eat food, not too much, mostly plants”. And the plant part is easy, right? Fruits, vegetables, nuts, seeds, beans, whole grains, herbs, spices. That’s the easy part. It’s the food part that’s a challenge because so much of what is presented to us in the supermarket and at restaurants and in the airport is not actually food. It’s edible food like substances. Long shelf-life products that are derived from food, and full of chemicals that are engineered to make us want to eat lots of them. They’re full of emulsifiers, artificial sweeteners, dyes, and preservatives, and these ultra processed foods are damaging our gut lining and our microbiome and contributing to this explosion of autoimmune diseases.
I’m not a dermatologist. I’m just a lowly butt doctor, but a lot of the patients I treat with autoimmune GI diseases like Crohn’s and ulcerative colitis also have psoriasis, and I’ve witnessed dramatic improvements in their skin when the inflammation in their gut clears up through a food as medicine approach. And that is part of why I’m so interested in the gut-skin connection, because I’ve seen firsthand how what’s going on in the gut profoundly impacts what’s showing up on the skin.
So I want to leave you with three takeaways about what you can do to improve your skin if you are struggling with a condition like psoriasis.
- Take the ultra-processed foods out of your diet completely. Those industrially manufactured food products with a long list of chemical ingredients. If you want to learn more about what an ultra-processed food is check out the Nova classification.
- Ramp up your consumption of unprocessed plant foods. I’m talking green leafy vegetables, fruits, beans, nuts, seeds, spices, herbs, whole grains. If you had to focus on just two, I strongly suggest beans and greens.
- Medications like steroids and biologics can be life changing for people with autoimmune diseases, but they come with significant risk because when you are suppressing the immune system, you are also increasing the risk of infection and cancer and other problems. Talk to your doctor about other options like coal tar.
For more on a gut-based approach to skin conditions like psoriasis, including specifics on what to eat, ingredients to avoid, safer ways to cleanse the skin, and my favorite edible skincare product recipes you can whip up in your kitchen, check out the Gutbliss Guide to Healthy Skin, which you can find at Gutbliss.com under GUT GUIDES.
Coming up next week on the Gutbliss Podcast: the final episode in our gut-skin series where I’ll be talking about eczema and rosacea.
