by Marion Nestle
Feb 27 2023

Industry funded study of the week: watermelon, of all things

The study: The Effect of Watermelon Juice Supplementation on Heart Rate Variability and Metabolic Response during an Oral Glucose Challenge: A Randomized, Double-Blind, Placebo-Controlled Crossover Trial.

Methods:  This was a two-week controlled clinical trial to measure the effects of watermelon juice on responses to oral glucose challenge tests in healthy young adults.  These usually decrease heart rate variability (not good).

Results: Watermelon juice countered the reduction in heart rate variability.

Funding: “This research was funded by the National Watermelon Promotional Board.”

Comment: I learned about this study from an article in NutraIngredients-USA: “Watermelon juice may decrease dysfunctsion linked to hyperglycemic episodes.” That headline made me ask my usual question: Who paid for this?  Bingo.

I give NutraIngredients much credit for the funding reveal right after the first paragraph, and for its clear explanation of a complicated study rationale and design.

The authors say they have no conflicts of interest to declare.  I continue to believe that the funding source establishes an automatic conflict of interest.

Once again, as I discuss in detail in my book, Unsavory Truth, the key point about industry-funded studies is that funding recipients do not recognize the influence or the conflict.

But what a coincidence that industry-funded studies so often come out with results favorable to the sponsor’s commercial interest, which in this case is this: The National Watermelon Promotional Board “operates with a single objective: to increase consumer demand for watermelon through promotion, research, and educational programs.”