Sugar molecules have been found in interstellar space, in meteorites, and on the asteroid Bennu, yet the same molecule sits at the center of a modern health crisis. This episode starts with the chemistry of simple and compound sugars, including glucose, fructose, galactose, lactose, maltose, and sucrose, and explains why humans evolved to crave sweetness.

We trace the word sugar from Sanskrit to English and follow sugarcane from India and New Guinea to the Caribbean plantations that drove the transatlantic slave trade. Then we cover how cane and beet sugar are refined, the ICUMSA purity scale, the 2008 Imperial Sugar refinery dust explosion, insulin resistance, WHO and American Heart Association limits, myths about cancer and hyperactivity, and industry-funded research in the 1960s.

• How glucose, fructose, and galactose share one chemical formula but behave differently, and galactose’s role in blood type
• How European sugar demand rose from about two pounds a year in 1650 to 90 pounds, fueled by slavery
• How cane and beet sugar are made, and why a lower ICUMSA number means purer white sugar
• Why sugar dust can explode, and how refined sugar leads to blood sugar spikes and insulin resistance
• What research says about sugar, cancer, and kids’ sugar rushes, and how the industry shaped dietary advice