You are a thoughtful person, good!
Your question is best understood from China's most basic philosophy. One of China's most basic philosophical thoughts is to follow the trend. In today's language, its philosophical point of view is to guide the situation according to the development trend of things.
To put it in vernacular Chinese, winter is a cold season, and the human body will collect the sun inward with the cooling of nature to reduce the external temperature. As a cold food for the human body, radish can promote the human body to collect the sun quickly and adapt to climate change. When the human body adapts to the climate, it won't get sick. Similarly, ginger is a hot food. Eating ginger in summer helps the human body to generate yang as soon as possible and adapt to the natural climate.