For patients with high blood sugar who have had the condition for a long time and exhibit poor blood sugar control, such diabetic individuals are prone to catching colds. This is because prolonged high blood sugar can cause a decline in the body's immune capacity, leading to insufficient ability to resist viruses and bacteria, thus making them susceptible to the common cold. Therefore, there is some basis to the claim that high blood sugar can lead to colds. For patients with high blood sugar, it is crucial to adhere to the dietary principles for diabetes management, which include consuming a low-sugar, low-fat diet, eating fresh vegetables, and fruits with a low glycemic index. It is also recommended that these patients regularly engage in physical exercise to enhance their immune system, improve their disease resistance, and reduce the occurrence of colds.