Editor's Note: This story is part of a new series on HealthCentral called "Get Your Ph.D.!", which is geared toward people who've got the basics of their condition down and want to up their expertise. Who's ready to go pro?!
If you have psoriasis, you'll try anything to get your flares under control. After all, you're spending more than an hour a day just trying to get your skin to behave. Naturally, if there was magic food that would fix your condition, you'd eat it for breakfast, lunch, and dinner, right? That's one reason that the keto diet, short for ketogenic, has been spreading by word-of-mouth among psoriasis patients as a possible way to curb flares. The diet, which is high in fat (more than 70% of daily calories) and low in carbohydrates, changes how your body uses energy, burning a chemical made in your liver called ketones (and, by extension, fat) instead of its usual glucose from carbs. It is touted for a myriad of health benefits, not the least of which is its ability to lower inflammation in the body—and that's music to the ears of anyone with psoriasis.
It ony makes sense, if you're giving up 60 minutes of your life every day to battle skin inflammation, that you'd sign up for a diet that does it for you. So is the keto diet the timesaver you've been looking for?
The Psoriasis-Keto Connection
It’s a logical leap—but not necessarily the correct one. Last year, a study in the Journal of Investigative Dermatology found that certain fats in the keto diet might actually worsen psoriasis symptoms. In that study, researchers in Austria discovered that while a keto diet that included fats from olive oil, fish, nuts, avocado, and meats didn’t affect skin inflammation, a keto diet focused on using fat from coconut oil, especially when combined with omega-3 fatty acids from fish oil and plant sources (like nuts and seeds), did.
The reason for skin inflammation on the coconut oil-based diet likely has to do with the molecular structure of the fat itself, researchers say. Coconut oil (as well as palm kern oil and to a lesser extent whole milk and butter) is rich in medium-chain triglycerides (MCT), whereas olive oil and avocados, in contrast, are heavy in long-chain triglycerides (LCT).
Your body uses these MCTs and LCTs for energy. Since MCTs are shorter in length than LCTs, they burn faster. But the real issue, as far as your psoriasis goes, is that a diet heavy in MCTs appears to cause the body to produce more damaging pro-inflammatory cytokines, signaling molecules involved in the body’s inflammatory immune response. MCT-rich foods like coconut oil also lead to a build-up of neutrophils, a type of white blood cell that can trigger a psoriasis flare. For reasons scientists are still figuring out, LCTs do not trigger the same response.
A few caveats about the study in Journal of Investigative Dermatology: It’s considered “preclinical” as it was done using lab animals, not humans. Also, the study also didn’t look at a whole foods approach to keto, meaning it didn’t replicate exactly how the diet might be used IRL, says Sarah Brookes, a registered nutritional therapist in London and founder of Autoimmune Hub, a digital network of specialists who work with people with autoimmune conditions.
Still, the results of this study and others suggest that the keto diet might not be the best option for psoriasis patients, Brookes says. She doesn’t recommend the keto diet to her clients—largely because of the plan’s extreme rules. “Eating shouldn’t be such hard work and it shouldn’t socially isolate you either,” says Brookes. “I tend to focus on diets that correct and balance the gut microbiome.”
Psoriasis and Weight Loss
Keto diet or not, if you have psoriasis and you’re overweight (often determined by a BMI of 25-30) or obese (BMI over 30), it’s time to take action. Research has found a link between obesity and inflammation, and carrying extra pounds is both a risk factor for psoriasis and can worsen the existing skin condition, says Sharleen St. Surin-Lord, M.D., a dermatologist and assistant professor of dermatology at Howard University College of Medicine in Washington, D.C.
In addition, psoriasis is associated with cardiovascular disease and metabolic syndrome (which can raise your risk of a heart attack)—two conditions that are also seriously impacted by your weight. Shedding pounds can help reduce your cardiovascular risk with psoriasis, research shows.
And that’s another reason why the keto diet might not be ideal for people with psoriasis: The high-fat diet favors butter and whole-fat dairy products that can raise your LDL cholesterol level, upping your cardiovascular risk. “Since psoriasis also shares a link with other chronic diseases—liver disease, cardiovascular disease—the keto diet may not be appropriate for this population due to its non-heart healthy nutrient profile,” says Amanda A. Kostro Miller, R.D., a registered dietitian in Chicago.
A Psoriasis-Friendly Diet
So, if you want to lose weight to help with your psoriasis and improve your heart health, what should you do? Start by eating a balanced diet that’s low in processed foods, says Dr. St. Surin-Lord.
Brookes agrees. “I would suggest people aim to eat a lot of fruits and vegetables, and eat healthy fats such as oily fish, eggs, avocado, and olives,” she says. “Most importantly, I think people should eat whole foods directly from nature and focus on optimizing digestion and absorption.”
Focusing on what not to eat can be helpful, too. “It’s more of, what do you need to avoid when it comes to psoriasis, because psoriasis is an inflammatory condition,” says Dr. St. Surin-Lord. “You want to avoid inflammatory foods like sugar, red meat, and dairy.”
Keeping a food journal when your psoriasis flares can help you determine if you have particular food sensitivities. “Generally, a diet void of trigger-foods like red meat, dairy, eggs, nightshade vegetables, or gluten is suitable for anyone with psoriasis,” says Tatiana Larionova, a licensed dietitian nutritionist and certified nutrition specialist in Miami, FL.
As for whether or not you should try keto, keep in mind that it may not be the fat itself, but the type of fat, that triggers your skin’s inflammatory reaction. Stick with LCTs like olive oil over MCTs like coconut oil when you’re cooking, and smear your toast with avocado instead of butter. Even then, the keto diet may not be the best option compared to more a personalized, balanced eating plan focused on food sensitivities, Brookes says.
“There isn’t a one-size-fits-all diet, and the ketogenic diet might benefit some people. However, in the case of an autoimmune disease, the key is to heal and rebalance the gut and then personalize the diet,” she says. With a little trial and error—and some thoughtful chats with your derm and dietician—you’ll be able to come up with an eating plan that’s best for you and your skin.