With cold and flu season upon us, there’s good reason to question the most common parables about immunity. Here, we leverage science to help deconstruct five of the most fabled assertions about health and the human condition.

Myth: Vitamin C prevents colds.

Truth: Not really, but it may reduce suffering time — a little bit. Meta-analyses examining whether prophylactic doses (200 milligrams) of vitamin C could prevent a cold revealed that there was no reduction in the frequency of catching a cold and only a little evidence — 8 to 14 percent — that it helped reduce the duration of colds. However, when looking specifically at skiers and marathoners in training, researchers found that a 200-plus-milligram dose of vitamin C cut their odds of getting a cold in half. If you regularly do high-intensity workouts, ensure you get your daily recommended 75 milligrams either through supplementation or through diet by way of dark leafy greens, bell peppers, tomatoes and sweet potatoes.

Myth: You should feed a cold and starve a fever.

Truth: Meh, sort of. There is an iota of veracity to this 16th century axiom, but in absence of conclusive scientific evidence, whether you should nosh really comes down to honoring your body cues. Fevers often spike because of bacterial infection, which also can cause nausea and suppress appetite, so it stands to reason that you’re probably not craving a pepperoni pizza if your temp is on the rise. In these instances, don’t force a feeding but rather focus on hydration. Colds, on the other hand, are viral and might not put a governor on your appetite, so go ahead and eat if you’re hungry.