Introduction: It's not long since summer began, and the sweet, red lychees have already arrived on the market in abundance. While everyone enjoys this delicious fruit, they can't help but worry about symptoms like limb weakness and a sore throat after eating it, which are often attributed to "heatiness." But why does eating lychees cause this so-called "heatiness"?
The most prominent characteristic of lychees is their sweetness. Generally, the sweetness of fruit is determined by two types of sugars: sucrose (which can be broken down into glucose and fructose) and fructose. Our bodies prefer glucose, as virtually all cellular activities rely on it for energy. Fructose, on the other hand, requires the liver to go through a process of converting some of it into glucose before the body can use it. The sweetness of lychees mainly comes from fructose. Due to the lack of glucose, parts of the body, including the brain, cannot function properly. Furthermore, people tend to eat less in the summer, which exacerbates the insufficient glucose supply, leading to symptoms of hypoglycemia such as dizziness, paleness, and fatigue—symptoms commonly mistaken for "heatiness."
Additionally, a small number of people may experience loss of appetite, diarrhea, and swelling after eating lychees. This is because their bodies lack the enzyme needed to metabolize fructose.
As for symptoms like a sore throat, fever, and sores, they are unrelated to eating lychees and certainly not linked to the quantity consumed. This misconception arises because lychees ripen during the summer, a period when various illnesses are common. For instance, Zhang San eats two jin of lychees and happens to get a sunstroke in the afternoon, leading to dizziness and other symptoms. Or, Li Si eats five jin of lychees and coincidentally catches a cold.
Therefore, to avoid "heatiness" when eating lychees, the most crucial factor is to maintain a stable blood glucose level. Some say that eating lychees soaked in light salt water prevents "heatiness," but in reality, salt water barely penetrates the lychee shell. Even if some salt soaks in, it doesn't affect the fruit's composition, nor does it raise blood glucose levels.
Others suggest drinking water boiled with lychee shells, but this is not advisable. There are no magical substances in lychee shells that can increase blood glucose. Moreover, the dust and preservatives that accumulate on the shells during transport might introduce new problems. The correct approach is to limit the amount of lychees you eat each time, ensuring it doesn't interfere with your regular diet, thereby reducing the burden on the liver to convert fructose. While eating lychees, also consume some starchy foods like bread or crackers. This helps maintain blood glucose levels and prevents "heatiness."