"In essence, snow is distilled water. Salts and contaminants have been boiled out of it," Onishchenko, who heads the consumer rights watchdog Rospotrebnadzor, said at a press conference in Moscow.
"But our air is polluted with gases, and the water has absorbed many bad substances, so the snow should not be eaten."
However, he said that drinking tea made of melted snow makes it possible to taste the tea's aroma, in contrast to tea brewed with running water.
The official did, however, warn Russians against drinking too much such tea, as not only harmful, but also beneficial substances are boiled out from snow when it is melted.
Onishenko said this could cause bone fragility and loss of teeth.
The doctor also warned Russians against eating too many pancakes during Maslenitsa celebrations.
Maslenitsa, also known as Cheesefare Week or Pancake Week, is marked in Russia during the week preceding the start of Great Lent, a period of fasting in Christianity, which this year begins March 18.
"If you consume too many pancakes, they will become a dangerous product, accumulating around your waist in half a day and staying there for a long time," Onishchenko joked.