Following up from my last post, I've spent the last two weeks following a strict exclusion diet (aka elimination diet) in an attempt to determine if the food I ate effected my psoriasis. The only food I was allowed during this experiment was brown rice and water (yes that meant no salt, soy sauce, olive oil or other forms of flavour).
The goal is for the restrictions to improve your symptoms to the point where they are consistently gone or much improved. Once they have stabilised in their new improved state you begin slowly reintroducing foods and wait to see what foods are problematic.
For the first week my psoriasis got slowly but steadily better, with a sudden improvement around day 8 (a Monday). However the following week it started to backtrack and by day 13 I was basically back where I started. The failure to reach an improved and stable plateau, combined with me getting quite light headed and lethargic in the final day, caused me to throw in the towel and start eating normally.
I'm disappointed, both with the results and in my bailing from the experiment. While it appears that diet doesn't play a significant role for me, my sister is sticking it out (good for her!) and is hopeful that she'll find some problem food culprits. I still believe that experimenting with diet in a controlled fashion like this is a powerful tool and could be helpful to many people. In the hope that it will be helpful to others, here is what I learned from this experiement.
The Royal Prince Alfred Hospital Allergy Unit is a wonderful resource to learn about food allergies, intolerance and elimination diets in general. I wish I'd found their site before I began my diet. They have lots of information available on their web site and have also published two books on the topic. Their first book, "Friendly Food" is primarily a cookbook which provides lots of yummy recipes for people who need to avoid a wide variety of foods. The introduction also has some great information and charts about the natural chemicals in food and how to introduce them into your diet. Most of the introduction is available online for free. I haven't read their second book, the "Elimination Diet Handbook" but I've ordered a copy and it looks great based on the introduction available online.
Following a diet this strict is hard. The challenge was the fun to start off with, but once the novelty wears off it gets boring and then a bit grim. In retrospect I think I'd try a less restrictive diet first but at the time it seemed simpler to do the hardest one first.
As your body detoxes expect waves of moodiness. Both Amy and I found day 2 and 3 particularly difficult and day 7 was brutal. Neither of us think we'd have made it if it wasn't for each others support. This also matches reports from friends who've tried similar diets.
When all you have is rice and water, get creative! There are a few different types of brown rice (short, medium and long grain). I accidentally burnt a batch of rice early on and the additional flavour was a welcome surprise. Hot water makes a surprisingly decent morning drink and sparkling water is a welcome change from tap water. Making rice tea is an easy and fun alternative too.
Make sure you eat enough. I got lazy (and really bored of rice) and wasn't eating nearly as much as I should have been. I think in part that's why day 7 was as tough as it was. After forcing myself to eat a big bowl of rice at the end of the day I perked up substantially.
Go easy with the exercise. The first week I was still running and did a big skate session on the weekend. The second week I tried running but it was unpleasant enough that I stopped. Eating only rice means you don't have the energy reserves to make exercise fun. On the last day an easy walk up the Wither Hills was enough to make me very light headed and a little dizzy.
Be careful changing your surroundings. Getting out of the city to visit my parents seemed like a pleasant change of pace, but it also took me from the environment where I'd learned my new habits. Had I stayed in Wellington I might have stuck it out for my third week, but visiting my parents provided plenty of excuses to quit (to be fair many of them were very reasonable reasons).
I kept a daily journal of my progress during the diet. I'll save the world from the details but if your are going to try this yourself and are interested in the nitty gritty I'm happy to share what I know.