[Cholesterol] levels are highest in the winter and lowest in the summer, according to a 2004 study in the journal Archives of Internal Medicine.
Out of 517 healthy people, 22 percent more people had high cholesterol (240 milligrams per deciliter of blood, or higher) in the winter months than in the summer months, according to the study.
The change in cholesterol levels could be attributed to people exercising less in the cold months, the study said, though more research is needed to find the exact reason why.
May I suggest starting that "more research" with an exploration into month-by-month eggnog consumption? Or the seasonally-adjusted frequency of parties with hot hors-d'oeuvres that can be described with the phrase "bacon-wrapped." I'd suggest a nutritional assay of fruitcake, but no one actually eats that.