Mediterranean Diet Study Retraction Is The Plan Still Good For Heart Health

The findings from the paper were held up as one strong example of how the style of eating — rich in fruits, vegetables, fish, whole grains, legumes, and moderate wine consumption — can improve health and longevity. To the shock of many readers and health professionals alike, this study (called the PREDIMED trial) was recently retracted from the NEJM for fraudulent data used in the results, raising the question: Is the Mediterranean diet all it’s cracked up to be for health and wellness? Long story short: Yes. But the retraction still matters, say researchers who weren’t involved in the study. RELATED: 10 Easy Mediterranean Diet Swaps to Make Today

A Closer Look at Why the Mediterranean Diet Study Was Retracted

One of the research associates on the retracted study, Yoshitaka Fujii, has been called out regarding the validity of the data he provided. It’s not the first — or 50th — time his work has been panned. In 2012, he was found to have fabricated data on 100 research papers, according to Retraction Watch, earning him the moniker “most prolific fraudster” in medical science. By 2015, the number of his retracted papers had reached 183. The current retraction sprang from a statistical analysis published in June 2017 by John Carlisle, of Torbay Hospital in the United Kingdom, who took various papers Fujii was involved in and analyzed the likelihood his data had actually been randomized. Randomization in research trials is necessary to determine if there is a cause-and-effect relationship between two factors, to eliminate the possibility that something else could be responsible for a study’s results. In considering the data set Fujii supplied to PREDIMED, Carlisle found that it was highly unlikely to have been randomized. While Carlisle’s analysis has resulted in many of the researcher’s papers being retracted, the NEJM article is noteworthy, especially in health research. In the study, the randomization groups allowed researchers to attribute the outcomes directly to the diet, which strengthens the results. Many studies looking at food intake and health outcomes rely on dietary recall, which isn’t as credible.

What the Updated Study Suggests About the Benefits of the Mediterranean Diet

In the new article — published on June 13, 2018 — the authors note that after learning of the inconsistencies from Carlisle’s report, they withdrew their previous study, reran the data, and revised the findings. Of the 7,447 initial participants, they excluded data from 1,558 of them because of fabrication. The new results: Those who ate a Mediterranean diet supplemented with olive oil or nuts enjoyed about a 30 percent reduction in cardiovascular events compared with the low-fat group. Put differently, the results are just about the same. “The general findings and conclusions of the PREDIMED study remain intact,” says Alice H. Lichtenstein, a senior scientist and the director of the Cardiovascular Nutrition Laboratory at the Tufts University Jean Mayer USDA Human Nutrition Research Center on Aging in Boston, who was not involved in the research. “The study authors took the appropriate steps of reanalyzing the data and informing the scientific community of the situation. As a result of the reanalysis, the findings and interpretation of the data were virtually unchanged,” she says. RELATED: 8 Budget-Friendly Ways to Follow a Mediterranean Diet There’s been another small shift: in the language describing the results. Rather than assert a cause-and-effect relationship, the authors write that there’s an “association” between these types of supplemented Mediterranean diets and lower cardiovascular risk. “Because randomization procedures were inadvertently violated in this trial, the authors have softened their language, presumably to satisfy editorial requirements,” says David Katz, MD, MPH, the founding director of Yale University’s Yale-Griffin Prevention Research Center, who also wasn’t involved in the study. “But when they reanalyze the data using only the properly randomized participants, the same association was observed, suggesting [it’s] as much ‘cause-and-effect’ as it ever was,” he adds. The bottom line, says Dr. Katz: This story really isn’t about the diet at all, but rather “the policing of the scientific literature by scientists,” he says. And clearly, that’s not a bad thing. “I think the scale of the problem in the PREDIMED study was sufficient to warrant retraction — I was surprised by the extent to which the intended random allocation process had been compromised (without the authors knowing),” Carlisle says. Doing these checks is important, he says, as scientists understand the idea that they’re never completely correct; searching for those errors is necessary. “This retraction illustrates how scientists and journals can work together to correct errors in science,” Carlisle adds.

Where the Mediterranean Diet Stands Overall After the Study Retraction

As Katz points out, because the results are virtually the same, the diet itself really isn’t in question. What’s more, the medical community’s knowledge surrounding the health benefits of this style of eating isn’t based solely on this study. “The Lyon Diet Heart Study showed the same a decade earlier,” says Katz, referencing a study published in Circulation. “Two of the world’s five blue zone populations have Mediterranean diets. Conclusions in science are virtually never based on one study. We have many studies and many populations showing the health benefits of a Mediterranean diet.” RELATED: Is the Mediterranean Diet Best for Diabetes? Another example: a study published in July 2016 in the European Heart Journal that looked at 15,000 people with heart disease from 39 countries found that those who followed the Mediterranean diet more closely were less likely to experience a subsequent stroke, heart attack, or death related to heart disease compared with those who followed it less closely. For comparison, the Standard American Diet — which is rich in animal fat, soft drinks, chips, cookies, and cake — may be responsible for nearly half of all deaths from stroke, heart disease, and type 2 diabetes, suggests a March 2017 study in JAMA. Now that you know the Mediterranean diet’s reputation as one of the healthiest plans to follow, you can feel confident sitting down to a hearty plate of garlicky greens and beans drizzled in olive oil. Though, as Katz points out in his own research review, there is no “best diet” that everyone should follow. What matters most: “minimally processed foods close to nature, predominantly plants.”

title: “Mediterranean Diet Study Retraction Is The Plan Still Good For Heart Health " ShowToc: true date: “2023-01-07” author: “Christopher Fennell”

The findings from the paper were held up as one strong example of how the style of eating — rich in fruits, vegetables, fish, whole grains, legumes, and moderate wine consumption — can improve health and longevity. To the shock of many readers and health professionals alike, this study (called the PREDIMED trial) was recently retracted from the NEJM for fraudulent data used in the results, raising the question: Is the Mediterranean diet all it’s cracked up to be for health and wellness? Long story short: Yes. But the retraction still matters, say researchers who weren’t involved in the study. RELATED: 10 Easy Mediterranean Diet Swaps to Make Today

A Closer Look at Why the Mediterranean Diet Study Was Retracted

One of the research associates on the retracted study, Yoshitaka Fujii, has been called out regarding the validity of the data he provided. It’s not the first — or 50th — time his work has been panned. In 2012, he was found to have fabricated data on 100 research papers, according to Retraction Watch, earning him the moniker “most prolific fraudster” in medical science. By 2015, the number of his retracted papers had reached 183. The current retraction sprang from a statistical analysis published in June 2017 by John Carlisle, of Torbay Hospital in the United Kingdom, who took various papers Fujii was involved in and analyzed the likelihood his data had actually been randomized. Randomization in research trials is necessary to determine if there is a cause-and-effect relationship between two factors, to eliminate the possibility that something else could be responsible for a study’s results. In considering the data set Fujii supplied to PREDIMED, Carlisle found that it was highly unlikely to have been randomized. While Carlisle’s analysis has resulted in many of the researcher’s papers being retracted, the NEJM article is noteworthy, especially in health research. In the study, the randomization groups allowed researchers to attribute the outcomes directly to the diet, which strengthens the results. Many studies looking at food intake and health outcomes rely on dietary recall, which isn’t as credible.

What the Updated Study Suggests About the Benefits of the Mediterranean Diet

In the new article — published on June 13, 2018 — the authors note that after learning of the inconsistencies from Carlisle’s report, they withdrew their previous study, reran the data, and revised the findings. Of the 7,447 initial participants, they excluded data from 1,558 of them because of fabrication. The new results: Those who ate a Mediterranean diet supplemented with olive oil or nuts enjoyed about a 30 percent reduction in cardiovascular events compared with the low-fat group. Put differently, the results are just about the same. “The general findings and conclusions of the PREDIMED study remain intact,” says Alice H. Lichtenstein, a senior scientist and the director of the Cardiovascular Nutrition Laboratory at the Tufts University Jean Mayer USDA Human Nutrition Research Center on Aging in Boston, who was not involved in the research. “The study authors took the appropriate steps of reanalyzing the data and informing the scientific community of the situation. As a result of the reanalysis, the findings and interpretation of the data were virtually unchanged,” she says. RELATED: 8 Budget-Friendly Ways to Follow a Mediterranean Diet There’s been another small shift: in the language describing the results. Rather than assert a cause-and-effect relationship, the authors write that there’s an “association” between these types of supplemented Mediterranean diets and lower cardiovascular risk. “Because randomization procedures were inadvertently violated in this trial, the authors have softened their language, presumably to satisfy editorial requirements,” says David Katz, MD, MPH, the founding director of Yale University’s Yale-Griffin Prevention Research Center, who also wasn’t involved in the study. “But when they reanalyze the data using only the properly randomized participants, the same association was observed, suggesting [it’s] as much ‘cause-and-effect’ as it ever was,” he adds. The bottom line, says Dr. Katz: This story really isn’t about the diet at all, but rather “the policing of the scientific literature by scientists,” he says. And clearly, that’s not a bad thing. “I think the scale of the problem in the PREDIMED study was sufficient to warrant retraction — I was surprised by the extent to which the intended random allocation process had been compromised (without the authors knowing),” Carlisle says. Doing these checks is important, he says, as scientists understand the idea that they’re never completely correct; searching for those errors is necessary. “This retraction illustrates how scientists and journals can work together to correct errors in science,” Carlisle adds.

Where the Mediterranean Diet Stands Overall After the Study Retraction

As Katz points out, because the results are virtually the same, the diet itself really isn’t in question. What’s more, the medical community’s knowledge surrounding the health benefits of this style of eating isn’t based solely on this study. “The Lyon Diet Heart Study showed the same a decade earlier,” says Katz, referencing a study published in Circulation. “Two of the world’s five blue zone populations have Mediterranean diets. Conclusions in science are virtually never based on one study. We have many studies and many populations showing the health benefits of a Mediterranean diet.” RELATED: Is the Mediterranean Diet Best for Diabetes? Another example: a study published in July 2016 in the European Heart Journal that looked at 15,000 people with heart disease from 39 countries found that those who followed the Mediterranean diet more closely were less likely to experience a subsequent stroke, heart attack, or death related to heart disease compared with those who followed it less closely. For comparison, the Standard American Diet — which is rich in animal fat, soft drinks, chips, cookies, and cake — may be responsible for nearly half of all deaths from stroke, heart disease, and type 2 diabetes, suggests a March 2017 study in JAMA. Now that you know the Mediterranean diet’s reputation as one of the healthiest plans to follow, you can feel confident sitting down to a hearty plate of garlicky greens and beans drizzled in olive oil. Though, as Katz points out in his own research review, there is no “best diet” that everyone should follow. What matters most: “minimally processed foods close to nature, predominantly plants.”