Thought others might be interested as wellMany of us have long been told that saturated fat, the type found in meat, butter and cheese, causes heart disease. But a large and exhaustive new analysis by a team of international scientists found no evidence that eating saturated fat increased heart attacks and other cardiac events.The new findings are part of a growing body of research that has challenged the accepted wisdom that saturated fat is inherently bad for you and will continue the debate about what foods are best to eat.
For decades, health officials have urged the public to avoid saturated fat as much as possible, saying it should be replaced with the unsaturated fats in foods like nuts, fish, seeds and vegetable oils.
But the new research, published on Monday in the journal Annals of Internal Medicine, did not find that people who ate higher levels of saturated fat had more heart disease than those who ate less. Nor did it find less disease in those eating higher amounts of unsaturated fat, including monounsaturated fat like olive oil or polyunsaturated fat like corn oil.
“My take on this would be that it’s not saturated fat that we should worry about” in our diets, said Dr. Rajiv Chowdhury, the lead author of the new study and a cardiovascular epidemiologist in the department of public health and primary care at Cambridge University...
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Found the article intriguing and many of us are interested in the subject, so I thought I would share.Although the study was done from 1966 to 1973, results weren’t available publicly until three years ago. It, too, found that a diet higher in unsaturated fats led to a higher rate of death from heart disease.
Why wasn’t this research published decades ago? It’s possible that modern computer technology allows us to do analyses that couldn’t be performed then. It’s possible that researchers tried, but were unable to get the results published.
But it’s also possible that these results were marginalized because they didn’t fit with what was considered to be “truth” at the time. The two principal investigators on the Minnesota study were Ivan Frantzand Ancel Keys, the latter of whom may be the most influential scientist in promoting saturated fat as the enemy of heart health. (Mr. Keys died in 2004.)
I’m not suggesting anything sinister. I’m sure that both these scientists absolutely believed that their prior epidemiologic work established that diets lower in saturated fat led to lower cholesterol levels and better health. Research consistently confirmed the former. When that lower cholesterol didn’t translate into actual outcomes like lower mortality, though, they must have been baffled.
Like others today, they may have been able to rationalize the result away and decide that it “has no relevance.” Unfortunately, other, similar controlled trials seem to support the notion that the case against saturated fat isn’t as robust as many think.
We all must be concerned about publication bias, which occurs when results of published studies are systematically different from results of unpublished studies. Research has shown that studies with statistically significant results are more likely to be published than those without. Studies with a low-priority topic or finding may be less likely to be published.
One of the reasons that epidemiologic evidence often leads us to conclusions that can’t be supported is likely publication bias. Studies that find significant associations between foods (like meat) and scary findings (like cancer) are more likely to be published than those that don’t find those associations. When controlled trials are finally done, though, the scary results often can’t be replicated.
But the most common reason research isn’t published is because researchers don’t write it up and submit it. That could be because they think it won’t be accepted. It could also be because they don’t believe the results. In the charged environment of nutrition research, when people’s careers are built on certain hypotheses, it’s hard not to imagine our biases creeping into play.
Unfortunately, the health of Americans and others is at stake. Should we be eating more polyunsaturated fats? Should we be avoiding saturated fats? The honest answer is: I don’t know. Given my review of the evidence, I stand by my previous recommendations, which essentially focus more on foods and less on nutrients. I think the state of nutrition research in general is shockingly flawed.
It’s hard enough to debate the data we can see. Knowing there’s probably data out there that people haven’t shared makes everything much, much harder.