(P19-015-24) The Effects of Watermelon Seed Consumption on Postprandial Glucose, Blood Pressure, and Gastrointestinal Comfort Perception

Objectives: Watermelon seeds are rich sources of protein, fat vitamins, minerals and fiber as well as phytochemicals. In spite of the various potential nutritional properties, the watermelon seeds are often discarded. There is also limited research on effects of watermelon seed consumption on health in human subjects. The objective of this study was to determine the effects of watermelon seed consumption on blood pressure, postprandial glucose, gastrointestinal response (GI), and bowel habits.

Methods: This study was conducted using a two trial, randomized crossover study design. Study participants (n=25; mean age 25.6 ± 6.6 years; BMI 24.2 ± 4.0 kg/m²) consumed watermelon seeds (170 kcal) or isocaloric unsalted pretzels (control) with a four-day washout. Participants completed questionnaires on gastrointestinal (GI) discomfort at baseline and 20, 40, 60 and 80 minutes post consumption using a visual analog scale. Bowel movement frequency was recorded each trial on the day before the trial and the trial day. Blood pressure was measured at baseline and twice every 20 minutes after consumption for 80 minutes. Blood glucose was measured at baseline, 40 and 80 minutes.

Results: Both watermelon seed and pretzel snacks demonstrated no significant change on GI discomfort (nausea, cramping, distension, or flatulence) but interestingly, reduced bowel movement frequency (P=0.006). Both snacks lowered systolic and diastolic blood pressure (P < 0.001). Watermelon seed consumption did not increase postprandial glucose while pretzel consumption caused a significant increase in postprandial glucose (P < 0.001).

Conclusions: This study concluded that watermelon seed consumption was associated with a significant improvement in postprandial blood glucose by limiting spikes in blood sugar. The consumption of watermelon seeds does not cause significant GI discomfort symptoms, indicating that watermelon seeds may serve as a healthy snack option and may be beneficial in reducing the risk of type two diabetes. Further research is warranted to explore long-term health outcomes as a function of watermelon seed consumption.

Funding Sources: This work was supported by the National Watermelon Promotion Board (DTD 11-03-23) and the SDSU 302L Advanced Nutrition Laboratory class.