TLDR:

• After 35 years of completely controlling Crohn's disease with azathioprine I ran into some serious problems.
• Turns out I can't tolerate an increased dosage of azathioprine (toxicity).
• Plan B: Trying to crash body weight to increase the effective dosage of the drug (mg/kg), without actually taking more.
• Unexpected: Ketogenic diet has substantial anti-inflammatory effect. If you suffer from an inflammatory disease it is actually worth giving it a try.

Update (8 weeks in)

• Lost 4 kg, which is a lot less than I hoped. But my strength has improved (benchpress 8 reps => 12 reps with consistent weight), so it seems there is some body recomposition going on due to weight training, and actual fat loss is probably more than that. But increasing muscle mass is counter-productive to my goal.
• Inflammation still very much improved over baseline, but the benefits plateaued after the first 4 weeks.
• I'm a lot more sensitive to 'bad' food now, but I have an alternative take on this: I think when you're on a 'normal' diet your normal state is kind of trash so you have no idea that some foods are messing you up. But after spending some time on an anti-inflammatory diet, your baseline state is much "cleaner", so when you eat something problematic it is immediately obvious. Standout inflammation villain: Deep fried foods in heavily reused (palm?) oil.

Plan B: Keto diet

Plan A was to increase the dosage of azathioprine, as I thought I had plenty of room to move. Turns out I don't, the metabolites hit this-will-kill-you levels and the doctor actually called and told me to stop. I had to go back to the original dose. Which sucks, because in terms of controlling Crohn's it was 100% effective.

Since I can’t tolerate a higher azathioprine dose, I am trying another approach: weight loss. My plan is to lose, say, 10 kg to increase the effective dose of the drug on a mg per kg basis without actually taking more.

My experience is that strict keto diets are good (easier) for weight loss, so I’ve been avoiding carbs for the last four weeks. I eat the bare minimum, and unintentionally this turned into a 'kinda' carnivore diet. I'm mostly eating meat (including fish and whey protein), olive oil, mushrooms, cottage cheese, nuts, incidental vegetables that get in my way and supplements. I would call it 'mostly carnivore'. I also resumed weight training to try and conserve muscle. So far, I’ve lost 3 kg. 

Unexpected consequences

After a couple of false starts, I got serious about it.

Here's the surprise: After two weeks, my symptoms improved, signficantly. Looking back, even during the false starts my symptoms were improving up until I blew the diet. After three weeks I was not quite normal but felt ok most of the time. Improvements seem to have plateaued around four weeks. There is still damage going on, so long term this is not great, but at least now I can function normally. 

I am certain that this diet is significantly reducing my symptoms, which was quite unexpected. I am equally certain that the disease will ramp up again if I resume normal eating.

Why is it working?

I don’t know why there is a substantial anti-inflammatory effect, but I have a few theories to test:

• Is it simply eating a lower volume of low-residue food?
• Do carbohydrates fuel Crohn’s?
• Does ketosis itself reduce symptoms?
• Is the full carnivore diet necessary or will a diverse keto diet work too?

Bowel rest is a known Crohn’s treatment, so it could be the low food volume. But I’ve previously had severe symptoms while physically starving, so I doubt that’s the answer.

Carbohydrates? Trust me when I say that everyone that gets Crohn's disease tries an elimination diet, and that for standard dietary patterns this does not work. But it is also true that people will normally rotate out the usual suspects such as wheat in favour of "safe" options like rice. Very few people would have tried eliminating carbohydrates as an entire class. 

Ketosis? There is mounting scientific evidence that ketogenic diets including paleo and carnivore can be effective treatments for a surprising range of disease. These include remission or reversal of type 2 diabetes, epilepsy, mental health disorders and a range of immune diseases. There are also some peer-reviewed case studies (not clinical trials) of individuals being successfully treated for Crohn's disease with such diets under medical supervision. I plan to review these in due course.

How does it work?

There are a few possibilities:

• Low carbohydrate intake decreases insulin secretion, which in turn reduces hyperglycaemia-induced inflammation. Basically, lower insulin levels correlate with reduced activation of inflammatory pathways.
• Ketones produced during ketosis directly inhibit inflammatory pathways, reducing systemic inflammation.
• Reducing grains, sugars and processed foods reduces intestinal permeability ("leaky gut"), decreasing immune activation by dietary irritants.

The first two points are real, scientifically-validated effects (although not in terms of their impacts on Crohn's disease). The third does not appear to be a consensus view as yet, but has gained a degree of crediblity.

Testing the hypothesis

After I hit my target weight (two to three months or so) I will run a few tests, gradually reducing controls to see if there are observable impacts:

1. Increase food volume (calories) to maintenance while maintaining a mostly carnivore diet. The idea here is to see whether it was simply bowel rest that improved my symptoms.
2. Shift to a keto diet with diverse plant content. I'll be adding salad and non-starchy vegetables to maintain ketosis, but abandoning a 'mostly' carnivore diet.
3. Shift to low carb (non-keto) diet. I will add small amounts of carbohydrate via whole-food sources, enough to break ketosis but I do not plan on eating huge amounts of carbs again.

My feeling is that the diverse keto diet will work, and the low carb diet will result in ramping up symptoms. But I'll do the experiement and we'll see.

Just so you know

Just to be clear, I'm still taking the azathioprine and it is still providing some degree of suppression. I can't live without it. So this is actually a combined treatment. This is not a 'cure'. There is no cure for Crohn's disease, let's just get over that and move on.

I'm also not a dietary zealot. I do not want to be on a carnivore or keto diet. I just want to eat pizza and live a normal life. But for people with Crohn's or other auto-immune diseases, sometimes the best choice you have is to take the one that is less SUCK.

Conclusion

If you are having difficulties with Crohn's disease, I suggest giving keto or carnivore a shot. It's not that bad, just make sure you include protein and fat in every meal, and you won't feel hungry. If it is going to work, my experience is that you'll start seeing tangible improvements after two weeks, ramping up over perhaps four. Frankly, the hardest part about keto is that normies think you'll immediately drop dead if you don't eat your carbs. You need to say no thank you and stay the course.

Try it for a month. If it doesn't work, you can always dump it and order a couple of pizzas, right?