Evidence check: LCT in the context of blood sugar

The question about LCT (lactase gene) in the context of blood sugar is relevant because lactase breaks down lactose into glucose and galactose. In individuals with lactase non-persistence (genetically determined by the LCT -13910 C/T polymorphism), lactose is poorly digested, leading to reduced glucose absorption from dairy. Studies indicate that lactose-intolerant individuals show a lower blood sugar rise after milk consumption compared to lactase-persistent individuals. However, the evidence is moderate: most studies are small or non-randomized. Additionally, dairy products contain fat and protein that modulate the glycemic response. For blood sugar management in diabetes or prediabetes, the impact of LCT status is generally small unless large amounts of milk are consumed. Importantly, lactose intolerance does not require complete avoidance of dairy; fermented products like yogurt or cheese are often well tolerated. The clinical relevance for blood sugar is limited, so individualized dietary advice is more useful than genetic testing alone. Caveat: No direct sources from the provided context; statements are based on general medical knowledge.