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.

Those are some of the conclusions of reports in the British Medical Journal’s annual Christmas issue, a compilation of the weird and light-hearted papers its editors accumulate over the year.

The supposed toxicity of poinsettias has been a subject of warnings as long as 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 Dr. Rachel C. Vreeman and Dr. 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 even produced any symptoms. Moreover, feeding experiments in animals show no effects even at very high consumption, they found.

Similarly, they 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, minimizing suicidal thoughts.

Other myths also are not supported by fact, they said. A variety of studies show 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 more 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 cure for a hangover that consistently works.