Lemon juice boosts gastric secretions and emptying rate, and reduces blood sugar response to starchy food, potentially due to acid-inhibition of digestion enzyme in saliva.
In this randomized, crossover study, 10 subjects consumed either water, lemon juice diluted in water, or black tea with bread at breakfast. Using magnetic resonance imaging, the finger-prick method, and visual analogue scales, researchers measured gastric volumes, the concentrations of glucose in the blood, and the perception of appetite over a period of three hours.
Discussion of Results: Lemon juice consumption resulted in a significant increase in gastric content volume, as well as a faster rate of gastric emptying, compared to water. It also elicited a lower glycemic response compared to water. However, no significant effect was observed with tea consumption. Correspondingly, changes in appetite perception and gastric volumes showed a strong correlation, though there were no significant differences among the different drinks. The findings suggest that the observed reduction in glycemic response could primarily be attributed to the interruption of starch digestion due to the acid-inhibition of the salivary enzyme responsible for starch hydrolysis.
