(In eighth paragraph, removes incorrect ratio reference to those with celiac disease.)
By Kathleen Kingsbury
BOSTON, Feb. 25 (Reuters) - When Alice Bast was diagnosed with celiac disease in 1994, she had to scour local health-food stores and send away to Canada for the gluten-free food her condition necessitated.
Two decades later, Jennifer Dillon received the same diagnosis but found gluten-free choices much closer to home - in the way of takeout from the Chinese restaurant down the street, options at the local supermarket, and on the shelves of a nearby CVS.
"I even bought gluten-free Girl Scout cookies last month," says Dillon, an attorney who lives in Arlington, Virginia.
Despite the difference in when the two women went gluten-free, they have something in common: The lofty price of their gluten-free diets is hard to swallow, coming at a significant premium to the price of conventional food items.
Dillon estimates that where she used to spend $90 per week on groceries for her family of four, her weekly bill now is at least $130.
Overall, Americans will spend an estimated $7 billion this year on foods labeled gluten-free, according to consumer research firm Mintel.
It can be twice as expensive to eat gluten-free, says Bast, who is president of the National Foundation for Celiac Awareness. "Our surveys tell us this is the number-one stressor for celiac patients, especially the newly diagnosed."
The University of Chicago's Celiac Disease Center estimates that about 3 million Americans have celiac disease, an autoimmune disorder that causes inflammation in the small intestine and leads to malnutrition.
Going sans gluten means more than giving up wheat-based bread, cereal, pasta, and beer. It's also found in less obvious products, such as soy sauce, salad dressing, even toothpaste.
Many people without celiac disease are excluding gluten as well from their diets, to combat food allergies, to ease gastrointestinal issues or arthritis, even to lose weight.
Indeed, avoiding gluten has quickly become the latest food fad in a long list, ranging from the low-fat diets of the 1980s to the Atkins and other diets in which the consumption of carbohydrates is avoided or limited.
According to consumer research firm Nielsen, the proportion of households reporting that they buy gluten-free products has jumped to 11 percent, from 5 percent in 2010. Celebrities such as Miley Cyrus and Elisabeth Hasselbeck have touted its benefits.
Health-conscious consumers are sold. A March 2013 survey by market research firm the NPD Group found that 29 percent of Americans were cutting back or avoiding gluten all together.
That number appears likely to rise.
"This is the health issue of the day," says Harry Balzer, chief industry analyst at NPD.
Brands as diverse as Anheuser-Busch and General Mills, betting that the hunger for gluten-free products will only grow, are promoting "gluten-free" versions of some of their best-selling products.
Indeed, burgeoning demand will help the gluten-free market to grow by some $4 billion by 2017, at no small cost to the consumer.
One 2008 study done at Canada's Dalhousie Medical School compared prices of 56 ordinary grocery items containing gluten with their gluten-free alternatives. All of the gluten-free products were more expensive, on average costing a jaw-dropping 242 percent more.
British researchers who conducted a similar study in 2011 found that the premium for gluten-free groceries ranged between 76 and 518 percent more than their wheat-based counterparts.
Part of the outsized prices come from the higher cost that manufacturers incur to make and market gluten-free products. In August, the U.S. Food and Drug Administration issued new, strict guidelines for certifying and labeling a food as "gluten-free."
While going gluten-free is the only treatment option for celiac patients, for others, gluten-avoidance may well be a waste of money.
In a 2012 essay in the Annals of Internal Medicine, Italian celiac researchers Antonio Di Sabatini and Gino Roberto Corazza note that there is no good test to diagnose nonceliac gluten sensitivity and, despite the hype, there is not enough scientific evidence of the health benefits that have been associated with going gluten-free.
Without further research, the authors warn against a "gluten preoccupation from evolving into the conviction that gluten is toxic for most of the population."
For those determined to eat gluten-free, fewer choices and availability continue to drive up the cost.
That's despite the fact that plenty of widely available, more reasonably priced food - such as fruit, vegetables, dairy and non-processed meat - is naturally gluten-free.
Still, more discount chains and big-box stores, including Wal-Mart, now carry gluten-free products. This benefits the consumer as it's somewhat brought down costs, and contributed to an improvement in the taste and texture of gluten-free foods, according to Bast.
"It used to be that a piece of gluten-free bread tasted like the cardboard box it came in and a pound of pasta cost $9.99," she says. "Today, finding less expensive (gluten-free) options is just a matter of shopping around and being more creative in your cooking." (Editing by Lauren Young and Bernadette Baum)