Lemon, however, showed its merits without fail. There are anecdotes and websites galore that claim lemon juice lowers glycemic index. Neither my researchers nor I could find any controlled studies showing evidence of a GI-lowering effect for lemon, lime, or citric acid. The closest was citrate, a salt or ester of citric acid in combination with other things like insoluble calcium. In my personal trials, three tablespoons of fresh-squeezed lemon juice just prior to eating (not store-bought with preservatives and artificial additives) appeared to lower blood sugar peaks by approximately 10%.
