David George Bailey, a Canadian track phenom turned doctor, died on August 27 at the age of 77. He is best known for his accidental discovery that certain fruit juices negatively impacted the efficacy of certain medications. He passed away at his home in London, Ontario, of a likely heart attack, according to The Globe and Mail.
Bailey was born on March 17, 1945, in Toronto. He was adopted by George and Barbara Bailey, a salesman and a homemaker, respectively. His mother’s cousin, a pediatrician, helped spark Bailey’s interest in science by showing him how insulin could help people with diabetes. As a child, he lost an eye in an accident, and even though this precluded him from participating in many sports, Bailey began running and found immense success.
Bailey made history in 1966 by becoming the first Canadian to run a mile in less than 4 minutes. In 1967, Bailey medaled in the 1,500-meter run at multiple international competitions, taking home the bronze medal at the Pan American Games in Winnipeg, Manitoba, and the silver the World University Games in Tokyo. The following year, he was on the Canadian Olympic team, competing at the 1968 games in Mexico City. He narrowly missed out on going to the semifinals after coming in sixth in his first-round heat (only the top five could advance).
He began studying pharmacy science as an undergraduate at the University of Toronto in 1964. He stayed there for his PhD, earning his degree in pharmacology in 1973. He completed a postdoc at the University of Saskatchewan and went on to work at the company now known as AstraZeneca, the Globe reports. In 1986, he began teaching at the University of Western Ontario (now known as Western University). The university had a partnership with what is now called the Lawson Health Research Institute, allowing Bailey new avenues for his research.
A few years later, Bailey was studying the interactions between alcohol and felodipine, a blood pressure medication. In one clinical trial, he tried using fruit juice to cover up the sharp taste of the alcohol before giving it to participants. He noticed that those who had the juice had much higher concentrations of the drug in their blood afterward, though it wasn’t clear at first whether it was the alcohol or the juice creating the odd reaction.
“So I decided to do a pilot study, on me, to find out,” he told Inside, a publication of the London Health Services Centre, in 2013. “Once I took the drug with water, then I took it with grapefruit juice. My drug levels were five times higher with grapefruit juice. That was a big eureka moment.”
In subsequent research, Bailey and others tested new combinations of drugs and juices to see if they reacted similarly, and also tested whether the timing of juice consumption mattered. Ultimately, he found that an intestinal enzyme, CYP3A4, was inhibited by flavonoids in the juice, which suppressed the metabolism of the drug and caused its concentration to reach unsafe levels.
Felodipine was far from the only medication to react with grapefruit juice. Over the years, it was discovered that more than 85 drugs—which treat a range of conditions from cancer to heart disease—are known to be affected by the juice. The list continues to grow each year. While some medications lose efficacy because of the juice, more than 40 are potentially lethal when consumed with juice because the body doesn’t metabolize it as quickly and it lingers in the system. The “grapefruit effect,” as it came to be known, led to labels on these medications warning patients to avoid the fruit at all times while taking the drug. Other citrus fruits were also found to produce the same effect.
According to an obituary written by his family, Bailey was predeceased in 2020 by his wife Barbara, and is survived by three children, their spouses, seven grandchildren, and a large extended family.