According to a 2016 randomized controlled study published in the Journal of Clinical and Diagnostic Research, consuming guava pulp (made from the vibrant red flesh of the fruit) without the peel had a significant and favorable effect on both lipid levels and blood sugar levels. More specifically, it lowered blood sugar, serum total cholesterol, triglycerides, and LDL cholesterol levels while also increasing HDL cholesterol levels. An older study published in the American Journal of Cardiology had similar results.
Science seems to point toward the beneficial soluble fiber content in the tropical fruit, which has a hypocholesterolemic (total cholesterol and LDL cholesterol-lowering) effect on the body. In addition to fiber, guava is packed full of antioxidants like vitamin C and vitamin A, and other nutrients like calcium, iron, and potassium. You can’t talk about high cholesterol levels without considering overall heart health, and guava is thought to be beneficial for heart health too for a few different reasons.