Oct. 16, 2000 -- Night after night during World War II, the bomber crews of Britain's Royal Air Force (RAF) climbed into their planes for perilous missions over Germany. The pilots had trouble seeing in the darkness, though, until one man's elderly relative whipped up a batch of bilberry jam. Once the heroic lads began tucking into the preserves before missions, they hit their targets with devastating accuracy.

Or so goes the story, repeated on countless web sites that offer bilberry supplements for sale. "RAF pilots who survived and continued consuming the jam or other Bilberry products had . . . perfect vision both near and far as well as a complete absence of eye disorders throughout their lives," writes Robert Biddleman on Herb.com.

Largely on the strength of that tale, bilberry -- a European cousin of the blueberry -- has become one of the 10 most popular herbs in the United States. According to The Hartman Group, a market research firm, bilbery's sales soared to $97 million in 1999, tripling in just two years.

Fascinated, WebMD set out to learn more. What we found, however, gave us little reason to increase our bilberry intake. Rather it tended to illustrate the power of a heartwarming tall tale over the cold facts of scientific research.

The Berry Hunt

We began our inquiry by trying to contact Biddleman, a Sonoma County, Calif., herbalist. Unfortunately, he was away on an herb picking expedition in Nepal. His colleague at Herb.com, Rebecca Starm, MD, maintained that he had contacted the pilots who continued to use bilberry after the war and had confirmed their extraordinary medical histories with their doctors and families. But she could offer no documentation.

Next we approached Thomas Dobie, MD, PhD. In addition to flying a Wellington bomber during World War II, Dobie now directs the National Biodynamics Laboratory at the University of New Orleans. With his combination of medical expertise and personal experience, Dobie seemed in a perfect position to confirm the tale. But while he snacked on wild bilberries as a child in Scotland, Dobie had no recollection of slathering bilberry jam on his wartime toast.

Perhaps the bilberries were served in a different mess hall, or after Dobie's tour of duty. So we asked Col. Mark Well, PhD, head of the history department at the U.S. Air Force Academy and author of a 1995 book on the experiences of World War II airmen, what he knew about the RAF's secret weapon. "In all my work on the RAF Bomber Command, I've never run across any reference to bilberry whatsoever," he said.

Puzzled, we turned to British experts at the RAF Museum, the Imperial War Museum, the RAF Centre of Aviation Medicine and the Bomber Command Historical Society. None could find so much as a smudge of jam in their files.

Of course, it's impossible to prove that no RAF pilot ate a bilberry during the Second World War. What really matters is whether the berries provide the benefits that advocates claim. According to the web site of the Vitamin Planet supplement stores, bilberry helps "control insulin levels and strengthen connective tissue," has "positive benefits toward hypoglycemia, inflammation, stress, anxiety, night blindness, and cataracts," and "may help halt or prevent macular degeneration."