This isn’t the first time that data from long ago have run against current recommendations. In 2013, an analysis was published of recovered data from the Sydney Diet Heart Study, a randomized controlled trial of a similar nature performed in men with a recent heart attack or angina. 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 Frantz and 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.