Some good news for the industry on Tax Day.
Consider the following headline: “Re-evaluation of the traditional diet-heart hypothesis: analysis of recovered data from Minnesota Coronary Experiment (1968-73).”
Based on that mouthful, it doesn’t sound like a very scintillating story, does it?
But the research study published by the British Medical Journal attempted to “examine the traditional diet-heart hypothesis . . . and to put findings [from the Minnesota Coronary Experiment] in the context of existing diet-heart randomized controlled trials through a systematic review and meta-analysis.”
Allow me to translate that into English, or given the source, into “American:” You can eat meat, cheese and butter, and you won’t drop dead from a heart attack.
You already knew that, but when a group of high-profile researchers, epidemiologists and medical scientists publishes a lengthy disclaimer in one of the world’s most prestigious medical journals, it adds a level of credibility that counters the relentless fascination of mainstream media with the “red meat will kill you” stories that amount to sound bites and snippets from retrospective analyses about diet and health that almost always end with the sentence, “More studies are needed.”
Which never deters reporters, writers and bloggers from jumping to conclusions unsupported by the very studies they try to quote.
Back to the future
The Minnesota Coronary Experiment attempted to examine the effects of eating either saturated fats or vegetable oils on mortality and heart disease rates. Some 9,000 participants were fed either on diets containing meat, milk and cheese or on diets with polyunsaturated fats, such as vegetable oils.
You might wonder, how did the researchers control the diets of 9,000 people? By using patients who were confined to either nursing homes or mental hospitals, back when the latter institutions still housed millions of people. After close to four years, which is what gives this study its aura of legitimacy, the researchers determined that eating plant-based oils did, in fact, reduce cholesterol levels in participants assigned to that diet.
And if you were around back in the ’70s and ’80s, you’ll recall the “horror” that high cholesterol levels triggered among nutritionists and medical professionals. Still does, only now it’s not a cudgel used to bend the Dietary Guidelines toward plant-based diets, but as a platform used to market a portfolio of profitable drugs like Crestor, Lipitor and Livalo.
Here’s why the BMJ’s resurrection of the Minnesota study matters: The original researchers noted that while consuming plant-derived fats did lower cholesterol values, it did not affect heart disease statistics.
To repeat: Avoiding meat and cheese lowered patients’ cholesterol levels, but it didn’t impact the incidence of heart disease.
However, and this is where the damage was done, those 1970s researchers theorized that, had their study continued, the (alleged) benefits of replacing saturated with unsaturated dietary fats would have positively affected the rates of heart attacks, strokes and other cardiovascular diseases.
Although the British scientists’ review noted that the results of the Minnesota study were never fully published, the researchers reported some of their results at a major American Heart Association conference 1975, and guess what the takeaway from that presentation was?
To paraphrase the Terminator, “Eat only plants if you want to live.”
To quote from an analysis of the British Medical Journal review on Reason.com, “The BMJ data recovery and reanalysis now finds that . . . for participants over age 65, lower cholesterol led to higher, rather than lower risks of death.”
So how has the American Heart Association responded to what was a thorough debunking of its “saturated fat = heart disease and death” hypothesis?
And I quote: “Eating foods that contain saturated fats raises the level of cholesterol in your blood. High levels of LDL cholesterol in your blood increase your risk of heart disease and stroke.”
Complete contradiction of not only the BMJ analysis, but those of numerous other analyses of other large-scale controlled trials.
But let’s end not with AHA’s simplistic and self-serving statement. Here’s the British researchers’ conclusion, and given the highly conservative language scientists use in discussing their findings, it amounts to a ringing endorsement of animal foods:
“Available evidence from randomized controlled trials shows that replacement of saturated fat in the diet with linoleic acid effectively lowers serum cholesterol but does not support the hypothesis that this translates to a lower risk of death from coronary heart disease or all causes. Findings from the Minnesota Coronary Experiment add to growing evidence that incomplete publication has contributed to overestimation of the benefits of replacing saturated fat with vegetable oils rich in linoleic acid.”
And “overestimation” is a serious underestimation of the damage done by 40 years’ of dietary gurus telling Americans that red meat bad, corn oil good. □
Dan Murphy is a food-industry journalist and commentator