Winter season is also flu season...eating certain foods can pump up the immune system and help our body to knock out invaders.
This article gives a very good idea of the "colorful" food that will keep stuffy noses away: Boost your immune system
"What we eat is very important in terms of how our immune system responds to pathogens and how well it can defend itself against a pathogen," said Dr. Simin Meydani (senior scientist and leader of the nutritional immunology team at Tufts University)
https://edition.cnn.com/2021/11/16/health/food-boost-immune-system-wellness/index.html