Realizing that there was little actual research into the effects of caffeine on human beings, the head of Coca Cola`s team of scientific experts suggested that a psychologist be hired to conduct a research study. After several prominent psychologists were approached, the team eventually recruited Harry Levi Hollingworth, a then-instructor at Barnard College. Given the stigma associated with applied work, Hollingworth was reluctant to accept the assignment but agreed on the condition that Coca Cola not use his results in their advertising or use his name to endorse their product. With the funds provided by Coca Cola, Hollingworth and his wife Leta (who was finally able to attend graduate school as a result of the windfall) designed and carried out one of the first comprehensive double-blind studies into the effect of caffeine on human health.
Despite the time constraints involved (due to the impending trial date), the Hollingworth study was designed to be as comprehensive as possible and ran for more than forty days. Using a six-room Manhattan apartment that had been specifically rented for the experiments, sixteen subjects (ten men and six women) ranging in age from nineteen to thirty-nine were recruited. As paid volunteers, they were expected to adhere to a series of conditions including abstaining from any caffeine or alcohol during the course of the study. A physician took careful measurements on the subjects who maintained daily records of their level of alertness, sleep habits, and general health. There were actually three separate studies with the longest running four weeks and involving multiple tests of cognition, perception, judgment, discrimination, and attention. Between test periods, subjects were free to relax in a leisure room reserved for their use For the first week, subjects received placebo capsules and baseline data was collected as they became adapted to the research routine. In the next week, subjects were divided into four groups with three groups receiving different doses of caffeine and the fourth group continuing with the placebo. Since it was a double-blind study, the experimenters working with the subjects and the subjects themselves remained unaware of whether the subjects were in the experimental groups or the control group. The caffeine dosages used were intended to reflect what a typical Coca Cola drinker might consume in a given day.
The second and third studies examined post-caffeine withdrawal as well as differing caffeine doses in specially prepared Coca Cola syrup when taken with food. Although the subjects were sent home at 6:30 pm each evening, the Hollingworths, along with the graduate students who were working on the project, often worked long into the night processing the more than 64,000 different measurements that had been collected (no computers in those days). As well, the Hollingworths maintained a duplicate set of the day's data to be housed in a separate location due to fears of the information being destroyed in a fire. When the data was presented at the trial (already underway in Chatanooga, Tennessee), Hollingworth's results quickly stood out from the other expert testimony that had already been presented. In his testimony, Hollingworth concluded that there was no evidence of caffeine producing any negative effects on cognitive or motor performance. A reporter from the Chattanooga Daily Times later described Hollingsworth's testimony (his name was misspelled) as "by far the most interesting and technical of any yet introduced. cross-examination failed to shake any of his deductions". Given that the Coca Cola trial was a major media event, Hollingworth (and applied psychology in general) received a major media boost.
The trial lasted another week but never reached the jury in the case. Presiding judge, Edward T. Sanford, acting on a motion from Coca Cola's attorneys, declared the government's case invalid and directed the jury to return a verdict in favour of the Coca Cola company. Since the case was thrown out on a technicality (over whether caffeine was an additive rather than simply an ingredient of Coca Cola), the question of caffeine's harmfulness was never actually addressed in the trial. With various appeals, the Coca Cola case dragged on until 1916 before the Appeals Court in Cincinnati, Ohio upheld the lower court decision. The case also marked the end of Harvey Washington Wiley's government career and he was forced to resign from his position in 1912. Not that this silenced him, mind you. He simply jumped ship and took over the laboratories of Good Housekeeping magazine as head of their Bureau of Food, Sanitation, and Health. He would continue in that position for eighteen years and often used the magazine to rail against caffeinated soft drinks as part of his crusade for truth in advertising.
With Coca Cola's victory, the company launched a major advertising campaign proclaiming its "vindication". That including publishing a brochure titled, Truth, Justice and Coca Cola, including a prominent picture of the company trademark with the scales of justice superimposed. The pamphlet also provided the names of the various expert witnesses who testified on the company's behalf (Hollingworth's name was omitted in keeping with his prior agreement with the company). Harry Hollingworth published his caffeine research results in 1912 as a comprehensive 166-page monograph as part of Robert Woodworth's series, Archives of Psychology. Given that Wiley's anti-caffeine campaign continued to stir up controversy, Hollingworth's study was frequently cited by medical researchers investigating the effects of caffeine (and still is). As the first comprehensive behavioural study of its kind, the Hollingworth caffeine study remains a classic in the area of industrial psychology.
In the meantime, Coca Cola continues its reign as the world's premier soft drink company. The role that Harry Hollingworth's testimony played in saving the company from financial ruin so long ago seems to have been quietly forgotten.
So it goes.