Contrary to popular belief, poinsettias are not toxic to people or animals, suicides do not increase over the Christmas holidays, and sugar does not make kids hyperactive. Also, Wales winning the rugby grand slam does not influence the death of popes, and douching with Coca-Cola is not an effective contraceptive method.
Those are some of the conclusions of reports in the British Medical Journal's annual Christmas issue, a compilation of the weird and lighthearted papers its editors accumulate over the year. In a related vein, a report in the journal Lancet details the curious case of a woman who fainted every time she ate a sandwich.
The supposed toxicity of poinsettias has been a subject of warnings ever since the red and white flowers have been associated with the Christmas holiday, but numerous reports from poison control centers do not support the warnings, according to Drs. Rachel C. Vreeman and Aaron E. Carroll of the Indiana University School of Medicine.
They reviewed nearly 900 calls to such centers reporting poinsettia consumption and found that none of the incidents resulted in serious illness and few produced any symptoms at all. Moreover, experiments with animals show no effects even at very high consumption, they found.
Similarly, researchers reviewed data on suicides in the United States for the last 35 years and found no increase before, during or after the holidays. In fact, despite widespread talk about winter gloom's effects on humans, they found that suicides peak in the summer and are lowest in winter. They conclude that people actually receive additional emotional and social support during the holidays, which decreases suicidal thoughts.
Other common beliefs are also not supported by fact, they said. Studies showed that children who consume large amounts of sugar are no more hyperactive than those who don't. But parents who think their kids have eaten sugar, even when they haven't, tend to rate them as being hyperactive.
The ill-mannered behavior, the authors wrote, was "all in the parents' minds."
Other myths that have been disproved: Not wearing a hat causes one to lose excessive body heat, and eating at night makes you more likely to pack on the pounds. Also, they found, there is no consistently effective cure for a hangover.
Coca-Cola douches for pregnancy prevention were a part of folklore in the 1950s and 1960s, before the contraceptive pill. People thought that the acidity of the soda would kill sperm and that the classic Coke bottle provided a convenient "shake and shoot" applicator.
Dr. Deborah Anderson of Boston University School of Medicine had previously reported that Coke can impede the mobility of sperm in a test tube. But further study, she said, shows that sperm get to the cervical canal so quickly that postcoital spritzing is ineffective.
For it to work, she wrote, the soda would have to be put in the vagina before sex, "but that would undoubtedly be messy."
Urban folklore in Britain holds that every time Wales wins the rugby grand slam, a pope dies -- except for 1978, when Wales was really good and two popes died. A grand slam occurs when, in a given season, a nation succeeds in beating all other competing teams in every match. Wales won a grand slam this year, and researchers were concerned for the health of Pope Benedict XVI.
Dr. Gareth C. Payne of University Hospital of Wales in Cardiff and his colleagues examined historical records and found that, of the eight pontiffs who have died since rugby events became common, five died in grand slam years. Wales accounted for only three of those grand slams, however, with England and Scotland achieving the others.
They found only a very weak statistical link between Welsh grand slams and papal deaths but, based on Wales' strong win over Italy this year, concluded that about 0.62 (about three-fifths) of a pope would die this year. "We do not believe the Vatican medical staff can fully relax until the new year begins," they wrote.
And finally, Drs. Christopher J. Boos and Howard Marshall, cardiologists at University Hospital Birmingham, treated a 25-year-old woman who suffered repeated fainting episodes, particularly when eating a sandwich or drinking a fizzy drink.
A full medical work-up showed her to be healthy overall, but the team ultimately diagnosed a condition called swallow syncope, which caused her heart to stop beating for as long as three seconds after some types of swallowing -- especially sandwiches, for no clear reason.
The woman was fitted with a pacemaker and has had no fainting episodes since, Boos and Marshall reported in the Lancet. They suspect that many other patients suffer the problem without being diagnosed.