🔬 The science behind smoothies & blood sugar When you blend fruit, you release natural glucose and fructose — which can raise blood sugar more quickly if you drink fruit alone. But here’s the good news: Adding high-fiber leafy greens (like spinach, kale, or romaine) dramatically slows glucose absorption. Fiber acts like a sponge, binding with glucose and releasing it gradually into your bloodstream. Plus, greens are loaded with chlorophyll, magnesium, and antioxidants that improve insulin sensi