In a Korean supermarket checkout area, I spotted a tub of gum making an unusual promise. Lotte’s I’m Control Banaba (아임 컨트롤 바나바) says it may help 식후 혈당상승 억제—limit the rise in blood sugar after eating. That is a lot of responsibility to give a piece of gum.

First, banaba (바나바) is not banana (바나나). Banaba is a tropical tree whose leaves contain compounds such as corosolic acid (코로솔산). The tub says it contains 0.7% banaba leaf extract powder. Lotte says each piece supplies 0.15 mg of corosolic acid. Its suggested routine is one piece before or after each of three meals, for 0.45 mg a day. (lotternd.com)