Fads in nutrition come and go, but one diet in particular has been widely heralded for its benefits to health – the “Mediterranean diet,” rich with vegetables, fruits, fish, nuts and olive oil. For decades, researchers have shown that people in Mediterranean countries seem to show lower rates of heart disease.
And in 2013, one landmark study gave the strongest proof yet in one of the first major clinical trials to measure the diet’s heart benefits. The study, conducted in Spain, showed that consuming a Mediterranean diet can lower the risk of a heart attack, stroke or death from heart disease by about 30 per cent in those at high risk.
The five-year experiment, published in the prestigious New England Journal of Medicine, made international headlines and was hailed as a triumph.
But on Wednesday, the study’s authors took the rare step of retracting their report. The researchers chose to withdraw their original paper and publish a new one after facing criticism of the way the initial experiment was conducted.
The findings of the revised study arrive at the same conclusions as the original one – that the Mediterranean diet can prevent heart disease. But the language in the new report is a bit more modest.
The “Mediterranean diet” is rich with vegetables, fruits, fish, nuts and olive oil.
The original study concluded the diet “resulted in a substantial reduction in the risk” of major heart illness among high-risk people, while the new study said “those assigned” to a Mediterranean diet had a lower risk than those not assigned.
Despite this softened language in the report, the lead author on the study, Dr. Miguel A. Martínez-González of the University of Navarra, told The Washington Post that the causal link is just as strong as the original report.
“We are now more convinced than ever of the robustness of the trial and of the conclusions,” Martinez-Gonzalez said, particularly because “no previous trial has undergone such intense scrutiny.”
Still, the retraction and replacement of such a major study in one of the world’s most reputable journals raised eyebrows in the medical world. If the original study was so problematic that the authors chose to withdraw it entirely, could the new one be trusted?
“Sad day for credibility of major medical journals and nutritional science,” tweeted Sekar Kathiresan, a physician scientist, human geneticist and director of the Center for Genomic Medicine at Massachusetts General Hospital.
The unusual chain of events began with the work of one determined sleuth, a British anesthesiologist named John Carlisle.
Since the early 2000s, Carlisle and a few others had been noticing red flags in studies published by academic anesthesiologist Yoshitaka Fujii. Nothing much came of it until about 2009, when Carlisle wrote to the top editor of the journal Anaesthesia raising doubt that Fujii’s data was produced by real-life experiments.
The issue had to do with randomized controlled trials, which divide participants by chance into separate groups that compare different treatments. Using chance “means that the groups will be similar and that the effects of the treatments they receive can be …read more