There’s no denying it: gluten-free has hit the mainstream. But, according to a new report, the specialty market is rising even faster than expected, and celiac disease isn’t the only reason.

Previous estimates by market research firm Packaged Facts projected that gluten-free sales would reach $2.6 billion by 2012. The firm’s latest report, however, estimates that annual sales have already passed that milestone, reaching $2.64 billion in 2010 alone. New estimates project the gluten-free market to hit nearly $5.5 billion by 2015.

While this news is a boon to the celiac and gluten intolerant community, the demand goes far beyond this niche group. According to a fall 2010 survey of 1,881 adults, including 277 gluten-free consumers, only 8-12 percent of those who purchase gluten-free goods do so because of celiac disease or gluten intolerance. Another 13 percent, however, buy gluten-free as a way to treat other conditions, according to the report. In some cases, conditions like autism and arthritis have been shown to improve with a gluten-free diet. Many consumers also believe gluten-free food is healthier and better quality, according to survey results.

Along with this report, there has been other evidence of gluten-free in the mainstream. A Chex commercial focusing on gluten-free options has won acclaim among celiac and gluten-free families. The recent Fancy Food Show showcased a number of new and popular gluten-free items, and the upcoming Natural Products Expo West will include a panel discussion, “Gluten-Free on the Menu” featuring National Foundation for Celiac Awareness Founder & President Alice Bast, along with other notables from the gluten-free scene.