The methodology and conclusion of a recent study linking consumption of Goji berry juice to improved energy and happiness have been criticized.
Paul Gross, PhD., contacted NutraIngredients shortly after our report of the study to voice his concerns. The study, which was funded by Arizona-based FreeLife International, a goji berry juice supplier, was also conducted by FreeLife employees.
According to the study’s findings, published in the Journal of Alternative and Complementary Medicine (JACM), people consuming the juice for 14 days reported increased ratings of energy levels, quality of sleep, mental acuity, calmness, and feelings of contentment, as well as improved regularity of gastrointestinal functions.
However, Dr Gross questioned the validity of the study, pointing out what he considered to be serious flaws in the plan, design and execution of the study. By both authors and all subjects being affiliated with FreeLife, the company sponsoring the study, Dr Gross said this creates “immeasurable potential for bias and lack of trust in the outcome by the scientific community.”
Dr Gross, the self-titled Berry Doctor, also asked why the company did not engage the services of a contract research organization and completely novel investigators and subjects.
Further questions were raised concerning the use of only two beverages, and no other experimental juices for comparison, while Dr Gross states that the researchers failed to control for the diets or personal habits of the subjects.
Looking further into the study methodology and findings, Dr Gross stated: “The study should have included larger numbers of subjects and should have had a longer duration. The fact that five female subjects were menstruating during the study indicates that hormonal effects may have influenced mood and subjective feelings of well-being.”
Dr Gross also noted that no data were provided concerning the entire nutrient analyses of the beverages.
Questions were also asked of the importance of the phytochemical LBP. Dr Gross said that a demonstration of the survival of LBP to the stomach and its presence in circulating blood was necessary. This would establish the bioavailability of LBP. He also stated that, despite references to Chinese abstracts, there exists no “scientifically acceptable evidence that LBP is the “most valuable” chemical constituent.”
“This project as a whole is a preliminary pilot study at best and is NOT a clinical trial, as is stated in Abstract and Methods,” said Dr Gross.
In his final statement, Dr Gross challenged FreeLife on its additional research to support the present study. “Despite claiming it is “#1 in Goji Research”, FreeLife has never published any study of goji in a reputable journal or engaged in any scientific forum about the goji berry,” he said.
Arizona-based FreeLife International was contacted for a response to Dr Gross’ comments. Peter Reilly, the company’s chief operating officer, told NutraIngredients that Freelife “welcomes a healthy and vigorous debate concerning the benefits of the goji berry and GoChi.”
“In FreeLife's initial groundbreaking study published in the Journal of Alternative and Complementary Medicine, participants drinking just four ounces daily of GoChi saw positive results in multiple health categories in as little as 14 days. This study was peer reviewed by two independent scientists.
“Building on the results of this first study, FreeLife completed two subsequent clinical studies showing that drinking 4 ounces of GoChi on a daily basis significantly improved the body's immune system and antioxidant capacity within just 30 days.
“These two additional studies were conducted at a prestigious research medical institution. Furthermore, the participants and scientists had no affiliation with FreeLife, and had no familiarity with GoChi or Himalayan Goji Juice prior to their start. Both studies have been submitted to journals and are pending for publication. FreeLife is currently conducting additional studies on the benefits of GoChi,” said Reilly.