Is the cure ever worse than the disease?

This week, millions of arthritis sufferers heard that a gluten-free, vegan diet would alleviate their symptoms. Many surely rejoiced and headed to stores to stock up, but many others surely either took the news as disheartening or immediately dismissed the diet as too hard or too expensive to follow, or both. An arthritis sufferer on a limited income or even a disability check may not have the means to buy gluten-free whole grains or to live on fresh produce.

The major problem I see with this study is that a "gluten-free vegan diet" was compared to a balanced diet that was neither, but they had no groups for one or the other. Are there studies asking whether a GF but not vegan, or vegan but not GF, diet helps?

The disheartening and difficult parts of this story:
1. It was shown that there was no improvement in symptoms or weight loss by participants eating a regular, balanced diet. If there is no point in striving for healthier habits and balance, some people will give up clinging to that last shred of trying for healthy habits.
2. It gets to the point where there is literally nothing we can eat. We're down to just organic produce, particularly locally grown. But wait--citrus fruits can interfere with medication and produce inflammation. Add in a few allergies and you're really scraping (I can't eat corn, which is a pretty common ingredient in GF/vegan food, and many people with nut allergies are also allergic to soy).