Researchers from the U.S. Department of Agriculture conducted a clinical study examining the effects of watermelon juice on healthy individuals. Participants consumed three and a half cups of watermelon juice, containing 780 grams of lycopene, daily for three weeks. The study found that this intake could double blood lycopene levels, reaching amounts comparable to those from tomato juice, although tomato juice contains more beneficial dietary fiber.
Dr. William W. Li, in his study "Eat to Beat Diet" (Lifestyle Publishing, 2024), noted that the optimal amount of watermelon juice provides maximum lycopene levels, as increasing the juice intake further did not enhance blood lycopene levels.
One advantage of watermelon over tomatoes, according to Dr. Li, is its citrulline content. This amino acid is metabolized by the body to produce nitric oxide, a chemical signal that regulates various life-sustaining cellular processes. Laboratory studies suggest that nitric oxide may enhance the production of brown fat for thermogenesis, protect vascular health, and lower blood pressure, countering metabolic syndrome. Additionally, nitric oxide promotes stem cell activity, aiding the regeneration of tissues and organs damaged by metabolic diseases.
For those interested in making their own watermelon juice, fresh watermelon yields a more refreshing taste than store-bought options, which often contain added sugar and artificial colors and flavors. Eating fresh watermelon pieces provides the benefits of juice along with added fiber. However, it's important to note that one cup of watermelon juice contains 2.2 times more sugar than tomato juice, so it should be consumed in moderation and not as a daily beverage.
Water is the best drink for hydration, followed by tea and coffee, which should be the primary choices for metabolic health. Other beverages should be consumed sparingly. It's crucial to listen to the body's thirst signals to avoid excessive fluid intake, which can be dangerous.
Excessive consumption of any liquid, including water, can lead to water intoxication, causing dangerous brain swelling. Limit fruit juice intake and focus on those with the highest health benefits. Most beverages can be easily made at home using a blender or juicer, and tea and coffee can be prepared with hot water. Cold tea or coffee can be stored in the refrigerator for a few days in glass or metal containers to avoid chemical leaching from plastic.