Cream cheese bagel.
© Linda Nylind
Cream cheese bagel.
The degree of legal peril in eating a poppy seed bagel, long rumoured and feared by the public, became clear only when two doctors conducted an experiment.

Elizabeth J Narcessian and HoJung Yoon, both at the University of Medicine and Dentistry of New Jersey, published their finding in a 1997 study called "False-Positive Urine Drug Screen: Beware the Poppy Seed Bagel" It concerned a patient whose urine mysteriously tested positive for morphine.

"The patient denied any use of illicit substances and denied obtaining medication from any other sources. Her pharmacy confirmed that I [Narcessian] was the only doctor prescribing Schedule II medications [illegal/classified drugs]. The patient was then questioned about her diet. She reported that her diet consisted predominantly of oatmeal cereal and bagels.

"The patient was requested to not eat any poppy seed bagels or poppy seed-containing food for a period of two weeks. She was requested to come to my office on 22 April 1997 with a poppy seed bagel. A urine sample was obtained from the patient at 9am before her ingesting the bagel. The patient was then observed eating one half of a poppy seed bagel.

"[The] results confirmed that ingestion of poppy seeds can result in a positive urine toxicology for morphine. The urines may remain positive from 24 to 48 hours after ingestion."

The degree of legal peril in eating a pumpernickel bagel, less well known to the public, was put on the public record years earlier. A terse, unsigned report called "Niacin Intoxication from Pumpernickel Bagels - New York", was published in 1983 in the Morbidity and Mortality Weekly Report.

"On 27 April 1983, 14 of 69 persons attending a brunch had acute onset of rash, pruritus and sensation of warmth ... Of 25 persons who ate the bagels, 14 became ill, whereas none of the 44 persons who did not eat pumpernickel bagels became ill.

"Because the bagels were very light in colour, the ingredients were suspected. Investigation revealed that, in an attempt to enrich the pumpernickel flour, a large quantity of niacin had been added. Laboratory studies revealed 60 times the normal level of niacin in the flour. On the basis of these data, each bagel contained approximately 190 milligrams of niacin. The recommended dietary allowance for niacin is [about] 13 milligrams/day for the average adult."

Thus we know that the risk of public intoxication from bagel consumption, though rare, is real.

- Marc Abrahams is the editor of Annals of Improbable Research and organiser of the Ig Nobel prize